inital commit

PROGREF/0_CONTS.A

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+
+_ _  |  |  _ _
+
+
+Contents
+
+_ ________________________________________________________________
+
+1 System Calls 1
+
+ 1.1 Introduction 3
+ 1.2 Standard Character Device I/O 4
+ 1.3 Memory Management 5
+ 1.4 Process Management 7
+ 1.5 File and Directory Management 9
+ 1.6 Microsoft Networks 14
+ 1.7 National Language Support 15
+ 1.8 Miscellaneous System-Management Functions 16
+ 1.9 Old System Calls 17
+ 1.10 Using the System Calls 21
+ 1.11 Interrupts 35
+ 1.12 Function Requests 53
+
+2 MS-DOS Device Drivers 323
+
+ 2.1 Introduction 325
+ 2.2 Format of a Device Driver 326
+ 2.3 How to Create a Device Driver 328
+ 2.4 Installing Device Drivers 329
+ 2.5 Device Headers 330
+ 2.6 Request Header 334
+ 2.7 Device Driver Functions 337
+ 2.8 The Media Descriptor Byte 351
+ 2.9 Format of a Media Descriptor Table 351
+ 2.10 The CLOCK Device 353
+ 2.11 Anatomy of a Device Call 354
+ 2.12 Two Sample Device Drivers 355
+
+3 MS-DOS Technical Information 383
+
+ 3.1 Introduction 385
+ 3.2 MS-DOS Initialization 385
+ 3.3 The Command Processor 386
+ 3.4 MS-DOS Disk Allocation 387
+ 3.5 MS-DOS Disk Directory 387
+ 3.6 File Allocation Table (FAT) 390
+ 3.7 MS-DOS Standard Disk Formats 392
+
+4 MS-DOS Control Blocks
+ and Work Areas 395
+
+  iii
+
+_ _  |  |  _ _
+
+
+_ _  |  |  _ _
+
+Contents
+
+ 4.1 Introduction 397
+ 4.2 Typical Contents of an MS-DOS Memory Map 397
+ 4.3 MS-DOS Program Segment 398
+
+5 National Language Support 403
+
+ 5.1 Introduction 405
+ 5.2 National Language Support Calls 405
+ 5.3 Font Files 406
+
+6 .Exe File Structure and Loading 411
+
+ 6.1 Format of a File Header 413
+ 6.2 The Relocation Table 414
+
+7 Microsoft Relocatable
+ Object Module Formats 417
+
+ 7.1 Introduction 419
+ 7.2 Module Identification and Attributes 423
+ 7.3 Conceptual Framework for Fixups 425
+ 7.4 Record Sequence 431
+ 7.5 Introducing the Record Formats 433
+ 7.6 Microsoft Type Representations
+  for Communal Variables 460
+
+8 Programming Hints 463
+
+ 8.1 Introduction 465
+ 8.2 Interrupts 465
+ 8.3 System Calls 466
+ 8.4 Device Management 467
+ 8.5 Memory Management 468
+ 8.6 Process Management 468
+ 8.7 File and Directory Management 469
+ 8.8 Miscellaneous 471
+
+
+iv
+
+_ _  |  |  _ _
+
+
+_ _  |  |  _ _
+
+
+Figures
+
+_ ________________________________________________________________
+
+Figure 1.1 Example of the 8088 Registers 25
+
+Figure 1.2 Sample Program with Common Skeleton 26
+
+Figure 2.1 Sample Device Header 330
+
+Figure 2.2 Attribute Word for Character Devices 333
+
+Figure 2.3 Attribute Word for Block Devices 333
+
+Figure 2.4 Request Header 335
+
+Figure 2.5 Format of a Boot Sector 352
+
+Figure 2.6 Format of a Clock Device 354
+
+Figure 4.1 Program Segment Prefix 402
+
+Figure 5.1 Font File Structure 407
+
+Figure 7.1 Location Types 427
+
+
+
+  v
+
+_ _  |  |  _ _
+
+
+_ _  |  |  _ _
+
+
+Tables
+
+_ ________________________________________________________________
+
+Table 1.1 Standard Character I/O Function Requests 4
+
+Table 1.2 Memory Management Function Requests 5
+
+Table 1.3 Process-Management Function Requests 7
+
+Table 1.4 Predefined Device Handles 9
+
+Table 1.5 File-Related Function Requests 10
+
+Table 1.6 File-Sharing Function Requests 11
+
+Table 1.7 Device-Related Function Requests 12
+
+Table 1.8 Directory-Related Function Requests 12
+
+Table 1.9 File Attributes 13
+
+Table 1.10 Microsoft Networks Function Requests 14
+
+Table 1.11 National Language-Support Function Requests 15
+
+Table 1.12 Miscellaneous System-Management Function Requests 16
+
+Table 1.13 Old System Calls and Their Replacements 17
+
+Table 1.14 Format of the File Control Block (FCB) 18
+
+Table 1.15 Error Codes Returned in AX 22
+
+Table 1.16 MS-DOS Interrupts, Numeric Order 27
+
+Table 1.17 MS-DOS Interrupts, Alphabetic Order 27
+
+Table 1.18 MS-DOS Function Requests, Numeric Order 28
+
+Table 1.19 MS-DOS Function Requests, Alphabetic Order 31
+
+Table 1.20 Bit values for Function 29H 133
+
+Table 1.21 Sharing Mode Bit Values 174
+
+Table 1.22 Access Code Bit Values 175
+
+Table 1.23 MS-DOS Data Bit Values 193
+
+Table 1.24 Contents of the Parameter Block 239
+
+Table 1.25 Contents of the Parameter Block 243
+
+Table 1.26  250
+
+Table 1.27 Allocation Strategy 263
+
+Table 2.1 For Character Devices: 331
+
+vi
+
+_ _  |  |  _ _
+
+
+_ _  |  |  _ _
+
+  Contents
+
+Table 2.2 For Block Devices: 331
+
+Table 3.1 MS-DOS Standard Removable-Disk Formats 393
+
+Table 3.2 MS-DOS Standard Removable Disk Formats (High-Density) 393
+
+Table 7.1 Object Module Record Formats 419
+
+Table 7.2 Combination Attribute Example 438
+
+
+
+  vii
+
+_ _  |  |  _ _
+

PROGREF/0_FRONT.A

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+
+_ _  |  |  _ _
+
+
+Microsoft (R)  MS-DOS
+Version 3.3
+_ ________________________________________________________________
+
+Programmer's Reference
+
+Microsoft Corporation
+
+_ _  |  |  _ _
+
+
+_ _  |  |  _ _
+
+All rights reserved.
+
+Simultaneously published in the United States and
+Canada.
+
+Microsoft(R), the Microsoft logo, MS-DOS(R), and XENIX(R) are registered trademarks
+of Microsoft Corporation.
+
+IBM(R), IBM Personal Computer(R), IBM PC(R), and PC-DOS(R) are registered trade-
+marks of International Business Machines Corporation.
+
+INTEL(R) is a registered trademark of Intel Corporation.
+
+Document No. 410630014-330-R04-0787 
+
+_ _  |  |  _ _
+

PROGREF/3_TECH.A

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+
+_ _  |  |  _ _
+
+  MS-DOS Technical Information
+
+ _ _______________________________________
+
+
+3.1 Introduction
+
+This chapter describes how MS-DOS initializes and how it allocates disk
+space for the root directory, the File Allocation Tables (FAT), and the
+data area. For programmers writing installable device drivers, this
+chapter explains MS-DOS disk directory entries and File Allocation
+Tables. At the end of the chapter, Tables 3.1 and 3.2 describe MS-DOS
+standard formats for floppy disks.
+
+3.2 MS-DOS Initialization
+
+MS-DOS initialization consists of several steps. When you reset your com-
+puter or turn on its power, the ROM (Read Only Memory) BIOS is invoked
+and performs hardware checks and initialization. The ROM BIOS then
+examines drive A for the boot sector. If it locates a boot sector, the ROM
+BIOS reads it into low memory and gives it control. If it doesn't find the
+boot sector, the ROM BIOS then looks in the active partition of the hard
+disk. If it still doesn't find the boot sector, the ROM BIOS then invokes
+ROM BASIC.
+
+On a removable disk (3.5-inch, 5.25-inch, or 8-inch disk), the boot sector
+sector is always located on track 0, sector 1, side 0 of the disk. On a hard
+disk, the boot sector begins on the first sector of the MS-DOS partition.
+The hard disk boot sector also includes a partition table. This table
+identifies the active MS-DOS partition and any other partitions, such as
+an extended MS-DOS partition, on the hard disk. Note that extended
+MS-DOS partitions are not bootable.
+
+The boot sector then reads the following files, in the order listed:
+
+io.sys
+msdos.sys
+
+_ ________________________________________________________________
+
+Note 
+
+ Versions of MS-DOS prior to 3.3 required the io.sys file to be contigu-
+ ous. This is no longer a requirement.
+
+_ ________________________________________________________________
+
+Next, the system initialization routine SYSINIT loads all of the resident
+device drivers. Then, it searches for a config.sys file on the boot disk.
+SYSINIT allocates memory for buffers and files, based on settings in the
+config.sys file, or system default settings. If the config.sys file specifies any
+
+  3
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+
+
+_ ______________
+
+installable device drivers, these are installed next.
+
+Finally, SYSINIT executes the MS-DOS command processor,
+command.com.
+
+3.3 The Command Processor
+
+The command processor command.com consists of three parts:
+
+ o A resident part resides in memory immediately following msdos.sys
+ and its data area. This part contains routines to process Inter-
+ rupts 22H (Terminate Process Exit Address), 23H (CONTROL-C Exit
+ Address), and 24H (Critical-Error-Handler Address), as well as a
+ routine to reload the transient part, if needed. All standard
+ MS-DOS error handling is done within this part of command.com.
+ This includes displaying error messages and processing the Abort,
+ Retry, Fail, or Ignore messages.
+
+ o An initialization part follows the resident part. During startup, the
+ initialization part is given control; it contains the processor setup
+ routine in the autoexec.bat file. The initialization part determines
+ the segment address at which programs can be loaded, and because
+ it is no longer needed, is overlaid by the first program that
+ command.com loads.
+
+ o A transient part is loaded at the high end of memory. This part
+ contains all the internal command processors and the batch file
+ processor.
+
+ The transient part of the command processor produces the system
+ prompt (A>, for example), reads commands from the keyboard (or
+ from batch files), and causes them to be executed. For external
+ commands, the transient part builds a command line and issues
+ Function 4BH (Load and Execute Program) to load and transfer
+ control to the program.
+
+
+3.4 MS-DOS Disk Allocation
+
+The area on a disk partitioned for use by MS-DOS is formatted as follows:
+
+ 1. Reserved area\(emvariable size
+
+ 2. First copy of File Allocation Table\(emvariable size
+
+
+
+4
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+  MS-DOS Technical Information
+
+ _ _______________________________________
+
+ 3. Additional copies of File Allocation Table\(emvariable size (optional)
+
+ 4. Root directory\(emvariable size
+
+ 5. File data area
+
+Space for a file in the data area is not preallocated. The space is allocated
+one cluster at a time. A cluster consists of one or more consecutive sectors
+(the number of sectors in a cluster must be a power of 2); the cluster size is
+determined at format time. All the clusters for a file are "chained"
+together in the File Allocation Table, discussed in greater detail in Section
+3.5, "File Allocation Table (FAT)." MS-DOS normally keeps a second copy
+of the FAT for consistency, except in the case of reliable storage such as a
+virtual RAM disk. Should the disk develop a bad sector in the middle of
+the first FAT, MS-DOS can use the second. This avoids loss of data due to
+an unreadable FAT.
+
+3.5 MS-DOS Disk Directory
+
+The format utility builds the root directory for all disks. This directory's
+location on the disk and the maximum number of entries are dependent on
+the media. Specifications for standard removable-disk formats are outlined
+later in this chapter. Note, however, that MS-DOS regards directories,
+other than the root directory, as files, so there is no limit to the number of
+files that the subdirectories under the root directory may contain.
+
+All directory entries are 32 bytes in length and are in the following format
+(note that byte offsets are in hexadecimal):
+
+Byte
+ Function
+_ ________________________________________________________________
+
+
+0-7 Filename. Eight characters, left-aligned and padded, if neces-
+ sary, with blanks. The first byte of this field indicates the file
+ status as follows:
+ _ _____________________________________________________
+
+ 00H The directory entry has never been used. This is used
+ to limit the length of directory searches, for perfor-
+ mance reasons.
+
+ 05H The first character of the filename contains an E5H
+ character.
+
+ 2EH The entry is for a directory. If the second byte is also
+ 2EH, the cluster field contains the cluster number of
+ this directory's parent directory (0000H if the parent
+ directory is the root directory). Otherwise, bytes 01H
+ through 0AH are all spaces, and the cluster field con-
+ tains the cluster number of this directory.
+
+  5
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+
+
+_ ______________
+
+ E5H The file was used, but it has since been erased.
+
+ Any other character is the first character of a filename.
+
+8-0A Filename extension.
+
+0B File attribute. The attribute byte is mapped as follows
+ (values are in hexadecimal):
+
+
+ Byte
+ Contents
+ _ _____________________________________________________
+
+ 01H File is marked read-only. An attempt to open the file
+ for writing using Function 3DH (Open Handle) results
+ in an error code being returned. This value can be
+ used in programs along with the other attributes in
+ this list. Attempts to delete the file with Function
+ 13H (Delete File) or Function 41H (Delete Directory
+ Entry) will also fail.
+
+ 02H Hidden file. The file is excluded from normal directory
+ searches.
+
+ 04H System file. The file is excluded from normal directory
+ searches.
+
+ 08H The entry contains the volume label in the first 11
+ bytes. The entry contains no other usable information
+ (except date and time of creation), and may exist only
+ in the root directory.
+
+ 10H The entry defines a subdirectory, and is excluded from
+ normal directory searches.
+
+ 20H Archive bit. The bit is set to "on" whenever the file
+ has been written to and closed.
+
+ Note: The system files (io.sys and msdos.sys) are
+ marked as read-only, hidden, and system files. Files
+ can be marked hidden when they are created. Also,
+ you may change the read-only, hidden, system, and
+ archive attributes through Function 43H (Get/Set File
+ Attributes).
+
+0C-15 Reserved.
+
+16-17 Time the file was created or last updated. The hour, minutes,
+ and seconds are mapped into two bytes as follows (bit 7 on
+ the left, 0 on the right):
+
+ Offset 17H
+ | H | H | H | H | H | M | M | M |
+
+ Offset 16H
+ | M | M | M | S | S | S | S | S |
+
+6
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+  MS-DOS Technical Information
+
+ _ _______________________________________
+
+ where:
+
+ H is the binary number of hours (0-23).
+ M is the binary number of minutes (0-59).
+ S is the binary number of two-second increments.
+
+
+18-19 Date the file was created or last updated. The year, month,
+ and day are mapped into two bytes as follows:
+
+ Offset 19H
+ | Y | Y | Y | Y | Y | Y | Y | M |
+
+ Offset 18H
+ | M | M | M | D | D | D | D | D |
+
+ where:
+
+ Y is the year, 0-119 (1980-2099).
+ M is the month (1-12).
+ D is the day of the month (1-31).
+
+
+1A-1B Starting cluster; the number of the first cluster in the file.
+
+ o Note that the first cluster for data space on all disks is
+ cluster 002.
+
+ o The cluster number is stored with the least significant
+ byte first.
+
+ o For details about converting cluster numbers to logical
+ sector numbers, see Sections 3.5.1 and 3.5.2.
+
+
+1C-1F File size in bytes. The first word of this four-byte field is the
+ low-order part of the size.
+
+
+3.6 File Allocation Table (FAT)
+
+This section explains how MS-DOS allocates disk space in the data area
+for a file by using the File Allocation Table to convert the clusters of a file
+to logical sector numbers. The device driver is then responsible for locat-
+ing the logical sector on the disk. Programs should use the MS-DOS file
+management function calls for accessing files. Programs that access the
+FAT are not guaranteed to be upwardly-compatible with future releases of
+MS-DOS. The following information is useful to system programmers who
+wish to write installable device drivers.
+
+The File Allocation Table is an array of 12-bit entries (1.5 bytes) for each
+cluster on the disk. For disks containing more than 4085 clusters, a 16-bit
+FAT entry is used.
+
+
+
+  7
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+
+
+_ ______________
+
+The first two FAT entries are reserved; however, the device driver may use
+the first byte as a FAT ID byte for determining media. For hard disks, the
+value of this byte is F8H. See Tables 3.1 and 3.2 for the media byte
+descriptors used for 8-inch, 5.25-inch, and 3.5-inch disks.
+
+The third FAT entry, which starts at byte offset 4, begins the mapping of
+the data area (cluster 002). The operating system does not always sequen-
+tially write (to the disk) files in the data area. Instead, the system allo-
+cates the data area one cluster at a time, skipping over clusters it has
+already allocated. The first free cluster following the last cluster allocated
+for that file is the next cluster allocated, regardless of its physical location
+on the disk. This permits the most efficient use of disk space, since if you
+erase old files, you can free clusters, which the operating system can then
+allocate for new files.
+
+Each FAT entry contains three or four hexadecimal characters, depending
+on whether it is a 12-bit or 16-bit entry:
+
+_ ________________________________________________________________
+
+(0)000 If the cluster is unused and available.
+
+(F)FF7 The cluster has a bad sector in it if it is not part of any
+ cluster chain. MS-DOS will not allocate such a cluster. So
+ for its report, the chkdsk command counts the number of
+ bad clusters, which are not part of any allocation chain.
+
+(F)FF8-FFF The last cluster of a file.
+
+(X)XXX Any other characters that are the cluster number of the
+ next cluster in the file. The number of the first cluster in
+ the file is in the file's directory entry.
+
+The File Allocation Table always begins on the first sector after the
+reserved sectors. If the FAT is larger than one sector, the sectors are con-
+tiguous. The operating system usually writes two copies of the FAT to
+preserve data integrity. MS-DOS reads the FAT into one of its buffers,
+whenever needed (open, read, write, etc.). The operating system also gives
+this buffer a high priority to keep it in memory as long as possible.
+
+3.6.1 How to Use the FAT (12-Bit FAT Entries)
+
+To get the starting cluster of a file, examine its directory entry (in the
+FAT). Then, to locate each subsequent cluster of the file, follow these
+steps:
+
+ 1. Multiply the cluster number just used by 1.5 (each FAT entry is
+ 1.5 bytes in length).
+
+ 2. The whole part of the product is an offset into the FAT, pointing
+ to the entry that maps the cluster just used. That entry contains
+ the cluster number of the next cluster of the file.
+
+8
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+  MS-DOS Technical Information
+
+ _ _______________________________________
+
+ 3. Use a MOV instruction to move the word at the calculated FAT
+ offset into a register.
+
+ 4. If the last cluster used was an even number, keep the low-order 12
+ bits of the register by using the AND operator with 0FFFH and the
+ register. If the last cluster used was an odd number, keep the
+ high-order 12 bits by using the SHR instruction to shift the register
+ right four bits.
+
+ 5. If the resultant 12 bits are 0FF8H-0FFFH, the file contains no
+ more clusters. Otherwise, the 12 bits contain the number of the
+ next cluster in the file.
+
+To convert the cluster to a logical sector number (relative sector, such as
+that used by Interrupts 25H and 26H (Absolute Disk Read/Write) and by
+debug), follow these steps:
+
+ 1. Subtract two from the cluster number.
+
+ 2. Multiply the result by the number of sectors per cluster.
+
+ 3. To this result, add the logical sector number of the beginning of
+ the data area.
+
+
+3.6.2 How to Use the FAT (16-Bit FAT Entries)
+
+To get the starting cluster of a file, examine its directory entry (in the
+FAT). Then, to find the next file cluster, follow these steps:
+
+ 1. Multiply the cluster number last used by 2 (each FAT entry is 2
+ bytes).
+
+ 2. Use a MOV WORD instruction to move the word at the calculated
+ FAT offset into a register.
+
+ 3. If the resultant 16 bits are 0FFF8-0FFFH, no more clusters are in
+ the file. Otherwise, the 16 bits contain the number of the next
+ cluster in the file.
+
+
+3.7 MS-DOS Standard Disk Formats
+
+MS-DOS arranges data clusters on a disk to minimize head movement.
+MS-DOS then allocates all the space on one track (or cylinder) before mov-
+ing to the next. It uses the sequential sectors on the lowest-numbered
+head, then all the sectors on the next head, and so on, until it has used all
+the sectors on all the heads of the track.
+
+
+
+  9
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+
+
+_ ______________
+
+The size of the MS-DOS partition on a hard disk determines the size of the
+FAT and root directory. Likewise, the type of floppy disk (tracks per side,
+sectors per track, etc.) determines how MS-DOS uses the disk. The remov-
+able disk formats listed in Tables 3.1 and 3.2 are standard and should be
+readable in the appropriate standard drive.
+
+
+10
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+  MS-DOS Technical Information
+
+ _ _______________________________________
+
+Table 3.1
+
+MS-DOS Standard Removable-Disk Formats
+
+_ _________________________________________________________________________
+
+Disk Size in inches  5.25  8 
+
+_ _________________________________________________________________________
+
+WORD no. heads   1  1  2  2  1  2  1
+
+Tracks/side   40  40  40  40  77  77  77
+
+WORD sectors/track   8  9  8  9  26  26  8
+
+WORD bytes/sector   512  512  512  512  128  128  024
+
+BYTE sectors/ cluster   1  1  2  2  4  4  1
+
+WORD reserved sectors   1  1  1  1  1  4  1
+
+Byte no. FATs   2  2  2  2  2  2  2
+
+WORD root directory entries   64  64  112  112  68  68  192
+
+WORD no. sectors   320  360  640  720  2002  2002  616
+
+BYTE media descriptor   FE  FC  FF  FD  *FE  FD  *FE
+
+WORD sectors/FAT   1  2  1  2  6  6  2
+
+WORD no. hidden sectors   0  0  0  0  0  0  0
+
+_ _________________________________________________________________________
+
+*The two media descriptor bytes are the same for 8" disks (FEH). This is not a misprint. To
+establish whether a disk is single- or double-density, try a read of a single-density address
+mark. If an error occurs, the media is double-density.
+
+Table 3.2
+
+MS-DOS Standard Removable Disk Formats (High-Density)
+
+_ _________________________________________________________________________
+
+Disk Size in inches  3.5 or 5.25   3.5   5.25 
+
+_ _________________________________________________________________________
+
+WORD no. heads   1  2  2  2  2  2
+
+Tracks/side   80  80  80  80  80  80
+
+WORD sectors/track   8  9  8  9  18  15
+
+WORD bytes/sector   512  512  512  512  512  512
+
+BYTE sectors/cluster   2  2  2  2  1  1
+
+WORD reserved sectors   1  1  1  1  1  1
+
+BYTE no. FATs   2  2  2  2  2  2
+
+WORD root dir entries   112  112  112  112  224  224
+
+WORD no. sectors   640  720  1280  1440  2880  2400
+
+BYTE media descriptor*   FA  FC  FB  F9  F0  F9
+
+WORD sectors/FAT   1  2  2  3  9  7
+
+WORD no. hidden sectors   0  0  0  0  0  0
+
+_ _________________________________________________________________________
+
+*The value F0H in the media descriptor byte may be used to describe other media types.
+
+
+  11
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+
+
+_ ______________
+
+
+Chapter 3
+
+MS-DOS Technical Information
+
+_ ________________________________________________________________
+
+3.1 Introduction 3
+
+3.2 MS-DOS Initialization 3
+
+3.3 The Command Processor 4
+
+3.4 MS-DOS Disk Allocation 4
+
+3.5 MS-DOS Disk Directory 5
+
+3.6 File Allocation Table (FAT) 7
+
+3.6.1 How to Use the FAT (12-Bit FAT Entries) 8
+
+3.6.2 How to Use the FAT (16-Bit FAT Entries) 9
+
+3.7 MS-DOS Standard Disk Formats 9
+
+
+
+12
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+
+
+ _ ______________
+
+
+12
+
+_ _  |  |  _ _
+
+
+

PROGREF/4_CTRLB.A

@@ -0,0 +1,393 @@
+
+_ _  |  |  _ _
+
+  MS-DOS Control Blocks and Work Areas
+
+ _ ______________________________________________
+
+
+4.1 Introduction
+
+This chapter describes a typical MS-DOS memory map and explains how a
+program is loaded into memory. It also describes the structure of an
+MS-DOS program segment and the contents of register segments for .exe
+and .com program files.
+
+4.2 Typical Contents of an MS-DOS Memory
+Map
+
+A typical MS-DOS memory map contains the following information:
+
+
+ +-----------------------------------------------------+
+ | ROM and Video Buffers |
+ +-----------------------------------------------------+
+ | Transient Part of COMMAND.COM |
+ +-----------------------------------------------------+
+ | |
+ | |
+ | |
+ | |
+ | Transient Program Area |
+ |- - - - - - - - - - - - - - - - - - - - - - - - - - -|
+ | |
+ | |
+ | |
+ | |
+ | External Commands and Utilities |
+ | |
+ +-----------------------------------------------------+
+ | Resident Part of COMMAND.COM |
+ +-----------------------------------------------------+
+ | MS-DOS buffers, control areas, & installed drivers |
+ +-----------------------------------------------------+
+ | |
+ | MSDOS.SYS |
+ +-----------------------------------------------------+
+ | IO.SYS and resident device drivers |
+ +-----------------------------------------------------+
+ | Interrupt Vectors |
+ 0 +-----------------------------------------------------+
+
+During system initialization, MS-DOS loads the io.sys and msdos.sys files
+into low memory (Note that in MS-DOS 3.3, these files are not required to
+be written contiguously to the disk). The io.sys system file is the MS-DOS
+interface to hardware. The msdos.sys system file includes MS-DOS inter-
+rupt handlers, service routines (Interrupt 21H functions).
+
+  3
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+
+
+_ ______________
+
+Next, the system initialization routine loads the resident and installable
+device drivers. Above the installable device drivers, MS-DOS writes the
+resident part of command.com. This part includes interrupt handlers for
+Interrupts 22H (Terminate Process Exit Address), 23H (CONTROL-C
+Handler Address), 24H (Critical-Error-Handler Address) and code to reload
+the transient part. The transient part of command.com is reloaded into
+high memory. It includes the command interpreter, the internal MS-DOS
+commands, and the batch processor.
+
+External command and utility (.com and .exe) files are loaded into the
+transient program area. MS-DOS also allocates 256 bytes for user stack
+used with .com files. User memory is allocated from the lowest end of
+available memory that fulfills the allocation request.
+
+4.3 MS-DOS Program Segment
+
+When you type an external command or execute a program through Func-
+tion 4BH (Load and Execute Program, also called EXEC), MS-DOS deter-
+mines the lowest available free memory address to use as the start of the
+program. The memory starting at this address is called the Program Seg-
+ment.
+
+The EXEC system call sets up the first 256 bytes of the Program Segment
+for the program being loaded into memory. The program is then loaded
+following this block. An .exe file with minalloc and maxalloc both set to
+zero is loaded as high as possible.
+
+At offset 0 within the Program Segment, MS-DOS builds the Program Seg-
+ment Prefix control block. The program returns from EXEC by one of five
+methods:
+
+ o By issuing an Interrupt 21H with AH=4CH
+
+ o By issuing an Interrupt 21H with AH=31H (Keep Process)
+
+ o By a long jump to offset 0 in the Program Segment Prefix
+
+ o By issuing an Interrupt 20H with CS:0 pointing at the PSP
+
+ o By issuing an Interrupt 21H with register AH=0 and with CS:0
+ pointing at the PSP
+
+_ ________________________________________________________________
+
+Note
+
+ The first two methods are preferred for functionality, compatibility,
+ and efficiency in future versions of MS-DOS.
+
+_ ________________________________________________________________
+
+4
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+  MS-DOS Control Blocks and Work Areas
+
+ _ ______________________________________________
+
+All five methods transfer control to the program that issued the EXEC
+call. The first two methods return a completion code. They also restore
+the addresses of Interrupts 22H, 23H, and 24H (Terminate Process Exit
+Address, CONTROL-C Handler Address, and Critical-Error-Handler Address)
+from the values saved in the Program Segment Prefix of the terminating
+program. Control then passes to the terminate address.
+
+If a program returns to command.com, control transfers to the resident
+portion. If the program is a batch file (in process), it continues. Other-
+wise, command.com performs a checksum on the transient part, reloads it
+if necessary, issues the system prompt, and waits for you to type another
+command.
+
+When a program receives control, the following conditions are in effect:
+
+For all programs:
+
+ o The segment address of the passed environment is at offset 2CH in
+ the Program Segment Prefix.
+
+ o The environment is a series of ASCII strings (totaling less than 32K)
+ in the form:
+
+ NAME=parameter
+
+ o A byte of zeros terminates each string, and another byte of zeros
+ terminates the set of strings.
+
+ Following the last byte of zeros is a set of initial arguments that
+ the operating system passes to a program. This set of arguments
+ contains a word count followed by an ASCII string. If the file is in
+ the current directory, the ASCII string contains the drive and path-
+ name of the executable program as passed to the EXEC function
+ call. If the file is not in the current directory, EXEC concatenates
+ the name of the file with the name of the path. Programs may use
+ this area to determine where the program was loaded.
+
+ o The environment built by the command processor contains at least
+ a comspec= string (the parameters on comspec define the path
+ that MS-DOS uses to locate command.com on disk). The last path
+ and prompt commands issued are also in the environment, along
+ with any environment strings you have defined with the MS-DOS
+ set command.
+
+ o EXEC passes a copy of the invoking process environment. If your
+ application uses a "keep process" concept, you should be aware
+ that the copy of the environment passed to you is static. That is,
+ it will not change even if you issue subsequent set, path, or
+ prompt commands. Conversely, any modification of the passed
+ environment by the application is not reflected in the parent pro-
+ cess environment. For instance, a program cannot change the
+ MS-DOS environment values as the set command does.
+
+  5
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+
+
+_ ______________
+
+ o The Disk Transfer Address (DTA) is set to 80H (default DTA in the
+ Program Segment Prefix). The Program Segment Prefix contains
+ file control blocks at 5CH and 6CH. MS-DOS formats these blocks
+ using the first two parameters that you typed when entering the
+ command. If either parameter contained a pathname, then the
+ corresponding FCB contains only the valid drive number. The
+ filename field is not valid.
+
+ o An unformatted parameter area at 81H contains all the characters
+ typed after the command (including leading and embedded delim-
+ iters), with the byte at 80H set to the number of characters. If you
+ type <, >, or parameters on the command line, they do not
+ appear in this area (nor the filenames associated with them).
+ Redirection of standard input and output is transparent to appli-
+ cations.
+
+ o Offset 6 (one word) contains the number of bytes available in the
+ segment.
+
+ o Register AX indicates whether the drive specifiers (entered with the
+ first two parameters) are valid, as follows:
+
+ AL=FF if the first parameter contained an invalid drive specifier
+ (otherwise AL=00)
+
+ AH=FF if the second parameter contained an invalid drive
+ specifier (otherwise AH=00)
+
+ o Offset 2 (one word) contains the segment address of the first byte
+ of unavailable memory. Programs must not modify addresses
+ beyond this point unless these addresses were obtained by allocat-
+ ing memory via Function 48H (Allocate Memory).
+
+
+For Executable (.exe) Programs:
+
+ o DS and ES registers point to the Program Segment Prefix.
+
+ o CS,IP,SS, and SP registers contain the values that Microsoft link
+ sets in the .exe image.
+
+
+For Executable (.com) Programs:
+
+ o All four segment registers contain the segment address of the ini-
+ tial allocation block that starts with the Program Segment Prefix
+ control block.
+
+ o .com programs allocate all of user memory. If the program invokes
+ another program through Function 4BH (EXEC), it must first free
+ some memory through Function 4AH (Set Block) to provide space
+ for the program being executed.
+
+
+
+6
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+  MS-DOS Control Blocks and Work Areas
+
+ _ ______________________________________________
+
+ o The Instruction Pointer (IP) is set to 100H.
+
+ o The Stack Pointer register is set to the end of the program's seg-
+ ment. The segment size at offset 6 is reduced by 100H to allow for
+ a stack of that size.
+
+ o A .com program places a word of zeros on top of the stack. Then
+ by doing a RET instruction last, your program can exit to
+ command.com. This method assumes, however, that you have
+ maintained your stack and code segments.
+
+Figure 4.1 illustrates the format of the Program Segment Prefix. All
+offsets are in hexadecimal.
+
+ (Offsets in Hex)
+0 -----------------------------------------------------------
+ | | End of | |
+ | INT 20H | alloc. | Reserved |
+ | | block | 04H |
+8 -----------------------------------------------------------
+ | | Terminate address | CONTROL-C exit |
+ | Reserved | (IP, CS) | address (IP) |
+ | | | |
+10-----------------------------------------------------------
+ |CONTROL-C | Hard error exit address | |
+ |exit | (IP, CS) | |
+ |address (CS)| | |
+ ---------------------------------------- |
+ | |
+ | Used by MS-DOS |
+ | |
+ | 5CH |
+ | |
+ -----------------------------------------------------------
+ | |
+ | Formatted Parameter Area 1 formatted as standard |
+ | unopened FCB 6CH |
+ -----------------------------------------------------------
+ | |
+ | Formatted Parameter Area 2 formatted as standard |
+ | unopened FCB (overlaid if FCB at 5CH is opened) |
+80-----------------------------------------------------------
+ | Unformatted Parameter Area |
+ | (default Disk Transfer Area) |
+ | Initially contains command invocation line. |
+ -----------------------------------------------------------
+100
+
+
+ Figure 4.1 Program Segment Prefix
+
+_ ________________________________________________________________
+
+Important 
+
+  7
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+
+
+_ ______________
+
+ Programs must not alter any part of the Program Segment Prefix
+ below offset 5CH.
+
+_ ________________________________________________________________
+
+
+
+8
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+
+
+ _ ______________
+
+
+Chapter 4
+
+MS-DOS Control Blocks
+
+and Work Areas
+
+_ ________________________________________________________________
+
+4.1 Introduction 3
+
+4.2 Typical Contents of an MS-DOS Memory Map 3
+
+4.3 MS-DOS Program Segment 4
+
+
+
+  1
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+
+
+_ ______________
+
+
+8
+
+_ _  |  |  _ _
+
+
+

PROGREF/5_NLS.A

@@ -0,0 +1,360 @@
+
+_ _  |  |  _ _
+
+  National Language Support
+
+ _ ____________________________________
+
+
+5.1 Introduction
+
+National language support for this version of MS-DOS 3.3 includes these
+major features:
+
+ o Country-dependent information
+
+ o Support for national keyboard layouts
+
+ o Programming interfaces for national language support
+
+ o Utility commands
+
+Country-dependent information is available on a per-country basis and
+includes the following:
+
+ o Time, date, and currency
+
+ o Lowercase-to-uppercase character-conversion tables
+
+ o Collating sequence for character sorting
+
+ o Valid single-byte characters used in filenames
+
+Selectable keyboard support for different keyboard layouts is provided.
+
+The MS-DOS 3.3 programming interfaces for national language support
+allow applications to use the country-dependent information just
+described. To access this information, applications do not need to change
+the current country code of the system.
+
+Utility commands allow the user to select the keyboard layout and system
+country code.
+
+This version of MS-DOS does not support right-to-left national languages.
+
+5.2 National Language Support Calls
+
+The following function calls allow an application to tailor its operation to
+the current country code and to accept or change the current code page.
+A country code defines the country in which you live or work. MS-DOS
+uses this code to prepare and assign default code pages for your system. A
+code page is a table that defines the character set you are using. A
+character set is a country-specific or language-specific group of characters
+that are translated from the code page table and displayed on your screen
+or printer. Each code page character set contains 256 characters.
+
+
+
+  3
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+
+
+_ ______________
+
+The following function calls are also used by MS-DOS 3.3 to support the
+National Language requirements:
+
+ o Function 44H, Code 0CH (Generic IOCtl) \(em supports code page
+ switching on a per-device basis.
+
+ o Function 65H (Get Extended Country Information) \(em returns
+ standard country information, and points to related case-map or
+ collating tables.
+
+ o Function 66H (Get/Set Global Code Page) \(em gets or sets the code
+ page used by the kernel and by all devices.
+
+These functions support access to country-dependent information, all of
+which resides in one file named country.sys.
+
+5.3 Font Files
+
+Font files, also called code page information files, contain the images of
+code page character sets for use by console-screen or printer devices.
+These font files are identified by a filename extension of .cpi. Four font
+files are included with MS-DOS 3.3:
+
+Font file
+ Supported device
+_ ________________________________________________________________
+
+ega.cpi Color console used with an EGA card
+
+lcd.cpi Liquid crystal display
+
+4201.cpi IBM Proprinter
+
+5202.cpi Quietwriter III printer
+
+
+5.3.1 Font File Structure
+
+The contents of printer or console-screen font files are structured as fol-
+lows:
+
+ +--------------------------------------+
+ | 22-BYTE File Header |
+ +--------------------------------------+
+ | WORD Information Header |
+ +--------------------------------------+
+ | 13-BYTE Code Page Entry Header |
+ +--------------------------------------+
+ | 6-BYTE Font Data Header |
+ +--------------------------------------+
+ | Variable size Font Header(s) |
+ +--------------------------------------+
+
+4
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+  National Language Support
+
+ _ ____________________________________
+
+ 
+
+
+ Figure 5.1 Font File Structure
+
+The font file fields are described in the following sections.
+
+5.3.1.1 File Header
+
+Each file must begin with a file header that includes the following:
+
+Length
+ Parameter
+_ ________________________________________________________________
+
+8 BYTES File tag
+
+8 BYTES Reserved
+
+WORD Number of pointers
+
+2 WORDS Offset
+
+where:
+
+File tag begins with the byte 0FFH and is followed by a string "font "
+(seven characters).
+
+Reserved is eight bytes of zeros.
+
+Number of pointers is the number of pointers in the header. For MS-DOS
+3.3, the value of this word should be 1.
+
+Offset is the two-word offset from the beginning of the file.
+
+5.3.1.2 Information Header
+
+Following the file header is a one-word information header:
+
+Length
+ Parameter
+_ ________________________________________________________________
+
+WORD Number of code pages
+
+where:
+
+Number of code pages is the number of code page entries in the file.
+
+
+  5
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+
+
+_ ______________
+
+
+5.3.1.3 Code Page Entry Header
+
+For each code page entry, a header in the following format is included in
+the font file:
+
+Length
+ Parameter
+_ ________________________________________________________________
+
+WORD Length
+
+WORD Pointer
+
+WORD Device type
+
+8 BYTES Device subtype
+
+WORD Code page ID
+
+WORD Reserved
+
+2 WORDS Offset
+
+where:
+
+Length is the size of the code page entry header.
+
+Pointer points to the next code page entry header (last header=0, 0).
+
+Device type is 1 if the device is a console screen, or 2 if the device is a
+printer.
+
+Device subtype names the type of console screen or printer. This field also
+determines the name of the font file. For example, if the subtype is
+"CGA," the font file name is cga.cpi
+
+Code page ID defines a valid three-digit code page identification number.
+Valid code page numbers are 437, 850, 860, 863, and 865.
+
+Reserved is eight bytes of zeros.
+
+Offset is a pointer to the Font Data Header.
+
+5.3.1.4 Font Data Header
+
+The Font Data Header includes the following fields:
+
+Length
+ Parameter
+_ ________________________________________________________________
+
+WORD Reserved
+
+WORD Number of fonts
+
+
+
+6
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+  National Language Support
+
+ _ ____________________________________
+
+WORD Length of font data
+
+where:
+
+Reserved must be 1.
+
+Number of fonts is equal to the number of fonts defined in the font file.
+
+Length of font data is equal to the size of the font-data portion of the font
+file.
+
+5.3.1.5 Font Header
+
+The font-data portion of a font file will vary for each device. The struc-
+ture of the font-data portion consists of a set of data for each font type.
+The following illustrates the data portion of a font file for a console-screen
+device:
+
+font_header: 
+ db 16, 8 ; character pixels 
+ ; (rows, columns)
+ db 0, 0 ; aspect ratio (unused)
+ dw 256 ; number of characters in set
+
+
+len_data equ ($ - font_header)
+
+
+
+
+  7
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+
+
+ _ ______________
+
+
+Chapter 5
+
+National Language Support
+
+_ ________________________________________________________________
+
+5.1 Introduction 3
+
+5.2 National Language Support Calls 3
+
+5.3 Font Files 4
+
+5.3.1 Font File Structure 4
+
+5.3.1.1 File Header 5
+
+5.3.1.2 Information Header 5
+
+5.3.1.3 Code Page Entry Header 6
+
+5.3.1.4 Font Data Header 6
+
+5.3.1.5 Font Header 7
+
+
+
+  1
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+
+
+_ ______________
+
+
+  7
+
+_ _  |  |  _ _
+
+
+

PROGREF/6_EXE.A

@@ -0,0 +1,203 @@
+
+_ _  |  |  _ _
+
+  .Exe File Structure and Loading
+
+ _ _______________________________________
+
+_ ________________________________________________________________
+
+Note
+
+ This chapter describes .exe file structure and loading procedures for
+ systems that use a version of MS-DOS earlier than 2.0. For MS-DOS
+ versions 2.0 and later, use Function 4B00H (Load and Execute a Pro-
+ gram) to load (or load and execute) an .exe file.
+
+_ ________________________________________________________________
+
+The .exe files produced by link consist of two parts:
+
+ o Control and relocation information
+
+ o The load module
+
+The control and relocation information is at the beginning of the file in an
+area called the header. Immediately following this header is the load
+module.
+
+6.1 Format of a File Header
+
+The header is formatted as follows (note that offsets are in hexadecimal):
+
+Offset
+ Contents
+_ ________________________________________________________________
+
+0-1 Must contain 4DH, 5AH.
+
+2-3 Number of bytes contained in last page; useful for reading
+ overlays.
+
+4-5 Size of the file in 512-byte pages, including the header.
+
+6-7 Number of relocation entries in table.
+
+8-9 Size of the header in 16-byte paragraphs. Used to locate the
+ beginning of the load module in the file.
+
+AH-BH Minimum number of 16-byte paragraphs required above the
+ end of the loaded program.
+
+CH-DH Maximum number of 16-byte paragraphs required above the
+ end of the loaded program. If both minalloc and maxalloc
+ are 0, the program is loaded as high as possible.
+
+EH-FH Initial value to be loaded into stack segment before starting
+ program execution. Must be adjusted by relocation.
+
+
+
+  3
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+
+
+_ ______________
+
+10-11 Value to be loaded into the SP register before starting pro-
+ gram execution.
+
+12-13 Negative sum of all the words in the file.
+
+14-15 Initial value to be loaded into the IP register before starting
+ program execution.
+
+16-17 Initial value to be loaded into the CS register before starting
+ program execution. Must be adjusted by relocation.
+
+18-19 Relative byte offset from beginning of run file to relocation
+ table.
+
+1AH-1BH The number of the overlay as generated by link.
+
+
+6.2 The Relocation Table
+
+The relocation table that follows the formatted area above, consists of a
+variable number of relocation items. Each relocation item contains two
+fields: a two-byte offset value, followed by a two-byte segment value.
+These two fields contain the offset into a word's load module. This item
+requires modification before the module is given control. The following
+steps describe this process:
+
+ 1. The formatted part of the header is read into memory. Its size is
+ 1BH.
+
+ 2. MS-DOS allocates a portion of memory depending on the size of
+ the load module and the allocation numbers (AH-BH and CH-DH).
+ MS-DOS then attempts to allocate 0FFFH paragraphs. This
+ attempt always fails, and returns the size of the largest free block.
+ If this block is smaller than minalloc and loadsize, there is no
+ memory error. But if this block is larger than maxalloc and
+ loadsize, MS-DOS allocates (maxalloc + loadsize). Otherwise, it
+ allocates the largest free block of memory.
+
+ 3. A Program Segment Prefix is built in the lowest part of the allo-
+ cated memory.
+
+ 4. MS-DOS calculates the load module size (using offsets 4-5 and 8-9)
+ by subtracting the header size from the file size. The actual size is
+ adjusted down based on the contents of offsets 2-3. The operating
+ system determines (based on the setting of the high/low load
+ switch) an appropriate segment, called the start segment, where it
+ loads the load module.
+
+ 5. The load module is read into memory beginning with the start seg-
+ ment.
+
+
+
+4
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+  .Exe File Structure and Loading
+
+ _ _______________________________________
+
+ 6. The items in the relocation table are read into a work area.
+
+ 7. MS-DOS adds the segment value of each relocation table item to
+ the start segment value. This calculated segment, plus value,
+ points to the module to which the start segment value is added.
+ The result is then placed back into the word in the load module.
+
+ 8. Once all relocation items have been processed, the operating sys-
+ tem sets the SS and SP registers, using the values in the header.
+ MS-DOS then adds the start segment value to SS and sets the ES
+ and DS registers to the segment address of the Program Segment
+ Prefix. The start segment value is then added to the header CS
+ register value. The result, along with the header IP value, is the
+ initial CS:IP to transfer to before starting execution of the pro-
+ gram.
+
+
+
+  5
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+
+
+ _ ______________
+
+
+Chapter 6
+
+.Exe File Structure and Loading
+
+_ ________________________________________________________________
+
+6.1 Format of a File Header 3
+
+6.2 The Relocation Table 4
+
+
+
+  1
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+
+
+_ ______________
+
+
+  5
+
+_ _  |  |  _ _
+
+
+

PROGREF/8_HINTS.A

@@ -0,0 +1,440 @@
+
+_ _  |  |  _ _
+
+  Programming Hints
+
+ _ ______________________________
+
+
+8.1 Introduction
+
+This chapter describes recommended MS-DOS 3.3 programming pro-
+cedures. By using these programming hints, you can ensure compatibility
+with future versions of MS-DOS.
+
+The hints are organized in the following categories:
+
+ o Interrupts
+
+ o System Calls
+
+ o Device Management
+
+ o Memory Management
+
+ o Process Management
+
+ o File and Directory Management
+
+ o Miscellaneous
+
+
+8.2 Interrupts
+
+ o Never explicitly issue Interrupt 22H (Terminate Process Exit
+ Address).
+
+ Only the DOS should do this. To change the terminate address,
+ use Function 35H (Get Interrupt Vector) to get the current address
+ and save it, then use Function 25H (Set Interrupt Vector) to
+ change the Interrupt 22H entry in the vector table to point to the
+ new terminate address.
+
+ o Use Interrupt 24H (Critical-Error-Handler Address) with care. The
+ Interrupt 24H handler must preserve the ES register.
+
+ An Interrupt 24H handler can issue only the system calls 01H-0CH.
+ Making any other calls destroys the MS-DOS stack and prevents
+ successful use of the Retry or Ignore options.
+
+ When using the Retry or Ignore options, you must preserve the SS,
+ SP, DS, BX, CX, and DX registers.
+
+ o When an Interrupt 24H (Critical-Error-Handler Address) is
+ received, always IRET back to MS-DOS with one of the standard
+ responses.
+
+ Programs that do not IRET from Interrupt 24H leave the system in
+ an unpredictable state until a function call other than 01H-0CH is
+ made. The Ignore option may leave incorrect or invalid data in
+
+  3
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+
+
+_ ______________
+
+ internal system buffers.
+
+ o Avoid trapping Interrupt 23H (CONTROL-C Handler Address) and
+ Interrupt 24H (Critical-Error-Handler Address). Don't rely on trap-
+ ping errors via Interrupt 24H as part of a copy protection scheme.
+
+ These methods might not be included in future releases of
+ MS-DOS.
+
+ o A user program must never issue Interrupt 23H (CONTROL-C
+ Handler Address).
+
+ Only MS-DOS may issue Interrupt 23H.
+
+ o Save any registers that your program uses before issuing Interrupt
+ 25H (Absolute Disk Read) or Interrupt 26H (Absolute Disk Write).
+
+ These interrupts destroy all registers except for the segment regis-
+ ters.
+
+ Avoid writing or reading an interrupt vector directly to or from
+ memory.
+
+ o Use Functions 25H and 35H (Set Interrupt Vector and Get Inter-
+ rupt Vector) to set and get values in the interrupt table.
+
+
+8.3 System Calls
+
+ o Use new system calls.
+
+ Avoid using system calls that have been superseded by new calls
+ unless the program must maintain backward compatibility with
+ MS-DOS versions before 2.0. See Section 1.9, "Old System Calls",
+ for a list of these new calls.
+
+ o Avoid using functions 01H-0CH and 26H (Create New PSP).
+
+ Use the new "tools" approach for reading and writing on standard
+ input and output. Use Function 4BH (Load and Execute Program)
+ instead of 26H to execute a child process.
+
+ o Use file-sharing calls if more than one process is in effect.
+
+ For more information, see File Sharing, in Section 1.5.2, "File-
+ Related Function Requests."
+
+ o Use networking calls where appropriate.
+
+ Some forms of IOCtl can only be used with Microsoft Networks.
+ For more information, and a list of these calls, see Section 1.6,
+ "Microsoft Networks,"
+
+4
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+  Programming Hints
+
+ _ ______________________________
+
+ o When selecting a disk with Function 0EH (Select Disk), treat the
+ value returned in AL with care.
+
+ The value in AL specifies the maximum number of logical drives; it
+ does not specify which drives are valid.
+
+
+8.4 Device Management
+
+ o Use installable device drivers.
+
+ MS-DOS provides a modular device driver structure for the BIOS,
+ allowing you to configure and install device drivers at boot time.
+ Block device drivers transmit a block of data at a time, while char-
+ acter device drivers transmit a byte of data at a time.
+
+ Examples of both types of device drivers are given in Chapter 2, "-
+ MS-DOS Device Drivers."
+
+ o Use buffered I/O.
+
+ The device drivers can handle streams of data up to 64K bytes. To
+ improve performance when sending a large amount of output to
+ the screen, you can send it with one system call.
+
+ o Programs that use direct console I/O via Function 06H and 07H
+ (Direct Console I/O and Direct Console Input) and that want to
+ read CONTROL-C as data should ensure that CONTROL-C checking is
+ off.
+
+ The program should ensure that CONTROL-C checking is off by using
+ Function 33H (CONTROL-C Check).
+
+ o Be compatible with international support.
+
+ To provide support for international character sets, MS-DOS
+ recognizes all possible byte values as significant characters in
+ filenames and data streams. MS-DOS versions before 2.0 ignored
+ the high bit in the MS-DOS filename.
+
+
+8.5 Memory Management
+
+ o Use memory management.
+
+ MS-DOS keeps track of allocated memory by writing a memory
+ control block at the beginning of each area of memory. Programs
+ should use Functions 48H (Allocate Memory), 49H (Free Allocated
+ Memory), and 4AH (Set Block) to release unneeded memory.
+
+  5
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+
+
+_ ______________
+
+ This allows for future compatibility. For more information, see
+ Section 1.3, "Memory Management."
+
+ o Use only allocated memory.
+
+ Don't directly access memory that was not provided as a result of a
+ system call. Do not use fixed addressing, use only relative refer-
+ ences.
+
+ A program that uses memory that has not been allocated to it may
+ destroy other memory control blocks or cause other applications to
+ fail.
+
+
+8.6 Process Management
+
+ o Use Function 4BH (Load and Execute Program, or EXEC) to load
+ and execute programs.
+
+ EXEC is the preferred call to use when loading programs and pro-
+ gram overlays. Using the EXEC call instead of hard-coding infor-
+ mation about how to load an .exe file (or always assuming that
+ your file is a .com file) isolates your program from changes in .exe
+ file formats and future releases of MS-DOS.
+
+ o Use Function 31H (Keep Process), instead of Interrupt 27H (Ter-
+ minate But Stay Resident).
+
+ Function 31H allows programs that are greater than 64K bytes to
+ terminate and stay resident.
+
+ o Programs should terminate using Function 4CH (End Process).
+
+ Programs that terminate by one of the following must ensure that
+ the CS register contains the segment address of the PSP:
+
+ o A long jump to offset 0 in the PSP
+
+ o Issuing an Interrupt 20H with CS:0 pointing at the PSP
+
+ o Issuing an Interrupt 21H with AH=0, CS:0 pointing at the PSP
+
+ o A long call to location 50H in the PSP with AH=0
+
+
+
+6
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+  Programming Hints
+
+ _ ______________________________
+
+
+8.7 File and Directory Management
+
+ o Use the MS-DOS file management system.
+
+ Using the MS-DOS file system ensures program compatibility with
+ future MS-DOS versions through compatible disk formats and con-
+ sistent internal storage.
+
+ o Use file handles instead of FCBs.
+
+ A handle is a 16-bit number that MS-DOS returns when a file is
+ opened or created using Functions 3CH, 3DH, 5AH, or 5BH (Create
+ Handle, Open Handle, Create Temporary File, or Create New File).
+ The MS-DOS file-related function requests that use handles are
+ listed in Table 1.5 in Chapter 1, "System Calls."
+
+ Although the default maximum number of open files is 20, this
+ limit can be raised to 64K by Function 67H (Set Handle Count).
+ For more information on this system call, see Chapter 1, "System
+ Calls."
+
+ You should use these calls instead of the old file-related functions
+ that use FCBs (file control blocks). This is because a file operation
+ can simply pass its handle rather than maintaining FCB informa-
+ tion. If you must use FCBs, be sure the program closes them and
+ does not move them around in memory.
+
+ o Close files that have changed in length before issuing an Interrupt
+ 20H (Program Terminate), Function 00H (Terminate Program),
+ Function 4CH (End Process), or Function 0DH (Reset Disk).
+
+ If you do not close a changed file, its length will not be recorded
+ correctly in the directory.
+
+ o Close files when they are no longer needed.
+
+ Closing unneeded files increases efficiency in a networking environ-
+ ment.
+
+ o If a program does use FCBs, that program should not close an FCB
+ file and then continue writing to it. This practice will not work in
+ a network environment, and is not recommended under any cir-
+ cumstances.
+
+ o Change disks only if all files on the disk are closed.
+
+ If you don't close all the files, any information in internal system
+ buffers may be written incorrectly to a changed disk.
+
+
+
+  7
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+
+
+_ ______________
+
+
+8.7.1 Locking Files
+
+ o Programs should not rely on being denied access to a locked region.
+
+ To determine the status of a region, first, attempt to lock it, then
+ examine its error code.
+
+ o Programs should not close a file with a locked region or terminate
+ with an open file that contains a locked region.
+
+ The result of this procedure is undefined. Programs that might be
+ terminated by an Interrupt 23H or Interrupt 24H (CONTROL-C
+ Handler Address or Critical-Error-Handler Address) should trap
+ these interrupts and unlock any locked regions before exiting.
+
+
+8.8 Miscellaneous
+
+ o Avoid timing dependencies.
+
+ Various machines use CPUs of different speeds. Also, programs
+ that rely upon the speed of the clock for timing are not dependable
+ in a networking environment.
+
+ o Use the documented interface to the operating system. If either
+ the hardware or media change, the operating system can use the
+ features without modification.
+
+ Don't use the ROM support provided by the OEM (Original Equip-
+ ment Manufacturer).
+
+ Don't directly address the video memory.
+
+ Don't use undocumented function calls, interrupts, or features.
+
+ These items may change or may not exist in future MS-DOS ver-
+ sions. If you do use these features, you will make your program
+ highly non-portable.
+
+ o Use the .exe format rather than the .com format.
+
+ .Exe files are relocatable; .com files are direct memory images that
+ load at a specific place and have no room for additional control
+ information. .Exe files have headers that can be expanded for com-
+ patibility with future MS-DOS versions.
+
+ o Use the environment to pass information to applications.
+
+ The environment allows a parent process to pass information to a
+ child process. The command.com file is usually the parent process
+ to every application, so it can easily pass default drive and path
+ information to the application.
+
+8
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+  Programming Hints
+
+ _ ______________________________
+
+
+Chapter 8
+
+Programming Hints
+
+_ ________________________________________________________________
+
+8.1 Introduction 3
+
+8.2 Interrupts 3
+
+8.3 System Calls 4
+
+8.4 Device Management 5
+
+8.5 Memory Management 5
+
+8.6 Process Management 6
+
+8.7 File and Directory Management 7
+
+8.7.1 Locking Files 8
+
+8.8 Miscellaneous 8
+
+
+
+  9
+
+_ _  |  |  _ _
+
+
+
+
+_ _  |  |  _ _
+
+
+
+ _ ______________
+
+
+  9
+
+_ _  |  |  _ _
+
+
+

README.BF

@@ -0,0 +1,238 @@
+	    DOCUMENTATION FOR MS-DOS 3.30 BUGFIX DISKETTE
+
+This diskette contains code for bugfixes in the MS-DOS 3.30 Release that
+are corrected in the Microsoft MS-DOS 3.30 Packaged Product.  These may also
+be corrected in an OEM's 3.30 product by utilizing the code on this diskette.
+To to this, just copy the files on this disk over the corresponding files in
+the DISTRIBUTION DISKETTE tree before doing the builds and making up your
+OEM product.
+
+     *********************************************************************
+
+     Problem:	FDISK: logical drive creation doesn't show on fdisk.
+
+	   Run FDISK. Create a primary partition and then an extended
+	   partition. While creating the extended partition the menu
+	   sequence to create logical drives in the extended partition
+	   should turn up, but it doesn't.
+
+     Solution:
+	   
+	   Difference in versions of the C compiler (we used C 4.0
+	   instead of C 3.0) exposed a bug in the forcing of a constant
+	   to a long unsigned number. The two compilers treat this
+	   differently. 
+
+	   Changes made were:
+	 
+	   a) FDISK.H : line 14  DOS_MAX = 64*1024 ....old
+				 DOS_MAX = 65536L  ....new
+	   b) INT13.C : (not related to problem, was just something
+			 noticed along the way)
+		   	line 148   max_head[0] ...old
+			   	   max_head[i] ...new
+
+
+     *************************************************************************
+
+     MS-DOS 3.30 Beta FORMAT d: /S on very small partitions problem
+
+     Description:    Attempting to do a FORMAT d: /S on a hard disk partition
+		that is smaller than the space required for the system files
+		resulted in the system files overwritting other partitions
+		and format reporting approximately 4 GB of free space.
+
+     Problem:	The problem is simply that a check is never done to see if
+		enough free space exists to load the system files after the
+		formatting is done.  This problem also occurs on PC-DOS 3.30.
+
+     Solution:	The solution is to add a check to make sure that there is
+		enough free space for the system files before we attempt to
+		copy them.  This was done by adding a routine called
+		CHKSPACE which is called just before WRITEDOS in the module
+		FORMAT.ASM.  CHKSPACE uses DOS interrupt Get Disk Free Space
+		and compares the number of available clusters with the number
+		required for the system files.	If the amount of free space
+		is greater than or equal to the amount of space required by
+		the system files, CHKSPACE returns with the carry flag clear.
+		Otherwise, it returns withe the carry flag set.  Following the
+		call to CHKSPACE is a check for carry.	If carry is set, the
+		message "No room for system on destination disk" is printed
+		and the system files are not copied.  If carry is not set,
+		control continues on to WRITEDOS.
+
+     Modules:	Fixing this bug required changing FORMAT.ASM, MESSAGES.ASM,
+		and MESSAGES.INC.
+
+     Documentation: The entry for "No room for system on destination disk" in
+		the messages section of the DOS manual states that this error
+		message is the result of a SYS command.  This should be changed
+		to read SYS or FORMAT.	In addition, the entry assumes that the
+		destination disk is always a diskette and suggests that the
+		appropriate action is to format a blank diskette with the /S
+		option.  This will do you no good if you are trying to add the
+		system files to a hard disk partition.	The recommended action
+		should include using FDISK to make the partition larger and
+		retrying the command if the error occured while attempting to
+		format a hard disk partition with the /S option.
+
+
+     **************************************************************************
+
+     Problem:	Volumes in abundance cause boot problems.
+
+	   Create primary partition and then the extended partition.
+	   in the extended partition create the maximum number of
+	   volumes permitted, i.e. 23. Try booting machine off a 3.30
+	   floppy the machine is down on its knees. Problem doesn't
+	   exist if you have volumes < 23. Problem only on 6M AT.
+
+     Solution:
+	
+	   MSBIO2 has a buffer of 23 BDSMs at the end. MSBIO2 is followed
+	   by MSHARD. Since the BDSMs are substancially long in size 
+	   the bios relocates MSHARD to the paragraph boundary after
+	   the last BDSM used. This works fine for volumes < 23. 
+	   However if all 23 BDSMs are used up MSHARD is relocated to
+	   the next para boundary which happens to be within MSHARD
+	   itself. So MSHARD ends up destroying itself.
+
+	   Fix - a para buffer between the last BDSM and MSHARD in 
+	   MSBIO2.ASM.
+
+
+     **********************************************************************
+
+     Problem:
+
+	   On exercising last two sysinit error messages dos code is
+	   displayed instead of just the messages.
+
+     Solution:
+
+	  In calculating the location where to load dos, a constant is
+	  used to indicate the size of the sysinit segment. this is 
+	  different for us. 
+
+     Changes:  In msequ.inc changed sysize from 200 to 203.
+
+     Further changes planned: Change the sysize constant to a variable sizing
+	  the sysinit segment.
+
+
+     *************************************************************************
+
+     Problem:  type filename > "=" hangs the system.
+
+	Not only = in quotes but any delimitor causes problems.
+
+	This comes from a basic lack of consistency in the treatment
+	of the role of the " character. In command line parsing anything
+	between " ----- " is not interpreted. But in forming filenames
+	a " is taken as a valid character. Once the '>' character is 
+	reached the parser begins forming the filename and takes " as
+	the first character. The following = is taken as a delimitor and
+	the filename ended. When the filename is formed the processing
+	returns to the command line parsing main routine and sees the 
+	next ". After this it just moves anything that comes along till
+	it meets the next quote and ends up destroying the stack.
+
+     Solution: changed filename parsing code to test for quote and decrement
+	  the number of quotes. File changed - tmisc1.asm
+
+
+     ************************************************************************
+
+     Problem:	DOS FDISK creates partition which overlaps Xenix partition.
+
+	   Create bad track table (xenix) and then a xenix partition 
+	   which occupies whole disk. then boot dos and create partiton
+	   asking it to use all of the space for dos. It just does that
+	   overlapping the partition over the xenix partition.
+
+     Problem:	3.3 fdisk was not handling the no space condition.
+
+     Solution:
+
+	   added code to detect no space condition and report error on
+	   such a condition. files changed fdisk.c and space.c. also
+	   when dos tries to create primary partition with a space 
+	   requested from the user added error message when there is
+	   no space.
+
+
+     ************************************************************************
+
+     Problem:
+
+     The bug is that the routine make_partition had been checking for a free
+     "slot" in the Master Boot Record and aborting the menu if there was none.
+     This action is not desirable if the user wishes to create a Logical DOS
+     volume in an existing Extended DOS Partition.
+
+     There are several circumstances where this problem becomes evident.
+     Probably the most common problem would be experienced on a large hard disk with several
+     DOS partitions defined on it (COMPAQ is not the only OEM to support
+     multiple DOS partitions on a hard disk...).
+
+     Consider a disk with 4 DOS partitions defined on it and the user wants to
+     delete ONE of the DOS partitions so that an Extended DOS partition may be
+     defined.  After doing this, the ext_create_partition routine allows the
+     user to define logical DOS volumes.
+
+     The user decides that the Logical DOS Volumes he previously created are not
+     satisfactory after having left FDISK, perhaps he had previously defined
+     only one Logical DOS Volume and it did not use the entire Extended
+     Partition.
+
+     This time FDISK will not allow the user to select the Create Logical
+     Volume menu option because there are no free "slots" in the Master Boot
+     Record although there may well be plenty of space within the Extended DOS
+     partition.
+
+     NOTE: This problem also occurs with the OS/2 implementation of FDISK.
+
+
+     *************************************************************************
+
+     Problem:  Extend file handle count is broken.
+
+     Solution: The para calculation code in handle.asm to calculate the number
+	  of paragraphs needed is coded wrongly. For handle values
+	  less than a para away from the maximum this will cause a carry.
+	  The subsequent rotate by 4 should shift the carry in. IBM 3.3
+	  doesn't use the appropriate rotate instruction.
+
+     **************************************************************************
+
+     Problem:	 Disk info initialisation in extended volume wrongly done.
+
+            The problem involves creation of Logical DOS Volumes in
+            an Extended DOS Partition.  As you know, each Logical DOS Volume
+            has a "dummy" Master Boot Record which is necessary to define
+            the extent of its Logical Volume and to indicate the location of
+            the next Logical Volume (if one exists).  The "dummy" Master
+            Boot Record for each Logical Volume (except the last one)
+            contains an entry with a system indicator byte with the value of
+            5 - this is the pointer to the next volume.  The END_HEAD number
+            of this type 5 record is ONE greater than the greatest physical
+            head number on the drive.
+    
+    
+            This occurs because the entries in the "max_head" array are
+            initialized to be one more than the greatest physical head
+            number in the routine "get_disk_info()" in the file INT13.C for
+            use in calculations.  The routine "write_ext_boot_to_disk" in
+            the file DISKOUT.C does not subtract one from the max_head value
+            before placeing it into the extended boot record - which is what
+            results in the "End_Head" field being wrong for the type 5
+            record.
+    
+            The line in "write_ext_boot_to_disk" where the subtraction
+            should take place is shown below...
+    
+            /* End head */
+            boot_record[0x1D3] = max_head[disk];
+
+     Solution:	 As mentioned above the line given above should be
+	    boot_record[0x1d3] = max_head[disk] - 1;

README.DIS

@@ -0,0 +1,776 @@
+	    SUPPLEMENT TO MS-DOS 2.XX/3.XX ADAPTATION GUIDE
+
+	 DOCUMENTATION FOR THE MS-DOS 3.30 DISTRIBUTION DISKETTES
+
+This documentation consists of release layout information, a diskette
+directory, instructions for use, and a list of differences between the
+CLONE VERSION and the MS VERSION.
+
+1. MS-DOS 3.30 RELEASE LAYOUT
+
+------------------------------------------------------------------------------
+|			      SOURCE CODE				     |
+|									     |
+|			  10 96 TPI diskettes				     |
+|			       readme.src				     |
+|     Not generally available to OEMS - For Customer Support/Maintenance     |
+------------------------------------------------------------------------------
+	 []	     [] 	    []		[]		 []
+	 []	     [] 	    []		[]		 []
+	SWITCHES SET FOR	   SWITCHES SET FOR	   SWITCHES SET FOR
+	   MS VERSION		    CLONE VERSION	    CLONE VERSION
+	 []	     [] 	    []		[]		 []
+	\[]/	     [] 	   \[]/ 	[]		 []
+	 \/	     [] 	    \/		[]	      BUGFIXES
+-------------------  []    -------------------	[]	      APPLIED
+|		  |  []    |		     |	[]		 []
+|   MS VERSION	  |  []    |  CLONE VERSION  |	[]		 []
+|  SUPPLEMENTAL   |  []    | MESSAGE MODULES |	[]		 []
+| MESSAGE MODULES |  []    |		     |	[]		 []
+|		  |  []    | For all files   |	[]		 []
+|  COMMAND.COM	  |  []    | except for those|	[]		 []
+|  DEBUG.EXE	  |  []    | with complete   |	[]		 []
+|  MORE.COM	  |  []    | source on the   |	[]		 []
+|  RECOVER.EXE	  |  []    | CLONE VERSION   |	[]		 []
+|  SHARE.EXE	  |  []    | DISTRIBUTION    |	[]		 []
+|  MSDOS.SYS	  |  []    | DISKETTES	     |	[]		 []
+|		  |  []    |  readme.mes     |	[]		 []
+|1 96 TPI diskette|  []    |1 96 TPI diskette|	[]		 []
+|avail. on request|  []    |avail. on request|	[]		 []
+-------------------  []    -------------------	[]		 []
+	 []	     [] 	     [] 	[]		 []
+	\[]/	    \[]/	    \[]/       \[]/		\[]/
+	 \/	     \/ 	     \/ 	\/		 \/
+------------------------   -------------------------   -------------------------
+|		       |   |			   |   |		       |
+|      MS VERSION      |   |	CLONE VERSION	   |   |MICROSOFT MS-DOS 3.30  |
+|     SUPPLEMENTAL     |   | DISTRIBUTION DISKETTES|   | PACKAGED PRODUCT      |
+| DISTRIBUTION DISKETTE|   |	  readme.dis	   |   |		       |
+|   1 96 TPI diskette  |   | 2 96 TPI diskettes    |   |  2 48 TPI DISKETTES   |
+| Available on request |   | In OEM Adaptation Kit |   | In OEM Adaptation Kit :
+------------------------   -------------------------   -------------------------
+			   -------------------------
+			   |	BUGFIX DISKETTE    |
+			   |   FIXES THAT MAY BE   |
+			   |APPLIED TO MS-DOS 3.30 |
+			   |	  readme.bf	   |
+			   |  1 96 TPI diskette    |
+			   | In OEM Adaptation Kit |
+			   -------------------------
+
+
+
+	Additional Materials that are part of the OEM Adaptation Kit:
+
+	2.XX/3.XX Adaptation Guide			1 96 TPI diskette
+
+	Machine Readable Documentation
+		User's Guide/User's Reference		2 96 TPI diskette
+		Programmer's Reference
+
+	Hard Copy Documentation
+		User's Guide
+		User's Reference
+		Programmer's Reference
+
+
+   Additional Material that is available on request through an OEM's
+   OEM Account Manager:
+
+	1. Undocumented System Calls Information
+	2. Microsoft MASM 4.00 Retail Package
+
+(Most OEMS either already have these two items or do not have a use for them)
+
+
+The CLONE VERSION DISTRIBUTION DISKETTES contain the files that were produced
+from MS-DOS SOURCE CODE assembled with the IBMVER switch on but the
+IBMCOPYRIGHT switch off.  They contain full SOURCE CODE to IO.SYS, MSBOOT,
+FORMAT.EXE, PRINT.EXE, SORT.EXE and partial source code to MSDOS.SYS to allow
+for the customization of DOSMES.INC. MSDOS32101 is a bootable disk.
+
+The MS VERSION SUPPLEMENTAL DISKETTE contains files that were produced from
+MS-DOS SOURCE CODE assembled with the MS-VER switch on and the IBMVER and
+IBMCOPYRIGHT switch off.  They contain the executables for the four files DEBUG,
+MORE, RECOVER and SHARE as well as partial source for MSDOS.SYS to allow for
+its customization.  These are all the files with version switches in them except
+for the files with complete source on the CLONE VERSION.
+
+The MS-DOS 3.30 PACKAGED PRODUCT contains file that were produced from MS-DOS
+SOURCE CODE assembled with the IBMVER switch on but the IBMCOPYRIGHT
+switch off.  These two disks that are identical to the disks in the manufactured
+packaged product.  There is a boot disk and supplemental disk.
+
+The CLONE VERSION MESSAGE MODULES contain all the source code that must be
+modified for translation to a language other than English.
+These message source modules can be modified, then assembled and linked with the
+object modules that are provided to make the executables.  The object modules
+in this release were made from MS-DOS SOURCE CODE assembled with IBMVER switch
+on and the MSVER and IBMCOPYRIGHT switches off. Code is provided to make all
+the executables on the CLONE VERSION DISTRIBUTION DISKETTES except for
+the files that have complete source provided on the CLONE VERSION DISTRIBUTION
+DISKETTES: IO.SYS, MSBOOT.BIN, FORMAT.EXE, PRINT.EXE, SORT.EXE, SYS.COM, and
+MSDOS.SYS (partial source).
+
+Microsoft now offers complete translations including documentation for the
+following languages: French, German, Spanish, Portuguese, Italian and Dutch.
+OEMs who would like one or more of these translations added to their OEM
+contract should contact their Microsoft OEM Account Manager.
+
+MS VERSION SUPPLEMENTAL MESSAGE MODULES contain all the source code that
+must be modified for translation to a language other than English for the
+six files: COMMMAND.COM, DEBUG.EXE, MORE.COM, RECOVER.EXE, SHARE.EXE and
+MSDOS.SYS.  They are used the same way as the CLONE VERSION MESSAGE MODULES,
+except the the files they are linked to have been assembled with the
+MSVER switch on.
+
+The MS-DOS CLONE VERSION DISTRIBUTION DISKETTES, and the PACKAGE PRODUCT
+DISKETTES are provided as a part the MS-DOS 3.30 Standard OEM ADAPATION KIT.
+
+The CLONE VERSION MESSAGE MODULES, the MS VERSION SUPPLEMENTAL MESSAGE MODULES
+and the MSVER SUPPLEMENTAL DISTRIBUTION DISKETTE, MODULES may be available to
+an OEM under special conditions by request through their Microsoft OEM Account
+Manager.
+
+The SOURCE CODE release is not generally available to OEMS, however, it is
+archived for support purposes by OEM Customer Support.
+
+The BUGFIX DISKETTE contains code that fixes certain known problems in the
+MS-DOS 3.30 Release.  These fixes have been applied to the MS-DOS 3.30
+PACKAGED PRODUCT, but were not applied to the the MS-DOS 3.30 OEM Release
+to maintain IBM COMPATIBILITY.	An OEM can use this code to apply these
+bugfixes to their product.  The specific bugs are described in the release
+notes and in the the README.BF file on the BUGFIX DISKETTE.
+
+
+
+2. Diskette Directories
+
+MS-DOS 3.20 CLONE VERSION DISTRIBUTION DISKETTES	   MS330DIS01
+
+io.sys		system file - BIOS
+msdos.sys	system file - DOS
+command.com	command interpreter
+
+distrib\bin	    <dir>
+
+append.com	utility to set a search path for data files
+assign.com	utility to assign a drive letter to a different drive
+attrib.exe	utility to change or display a file's attribue (read/read only)
+backup.com	utility to backup one or more files from one disk to another
+chkdsk.com	utility to scan disks, check for allocation errors & repair them
+debug.com	utility for debugging
+diskcomp.com	utility to compare to contents of one disk with another
+diskcopy.com	utility to copy disks formatting when necessary
+edlin.com	line editor
+exe2bin.exe	utility to convert .EXE files to .COM files
+fdisk.com	utility to configure hard disk
+find.exe	filter to find text strings in files
+format.com	utility to format disks
+graftabl.com	graphic character generation driver
+graphics.com	utility to print a graphics display on a printer
+join.exe	utility to join a drive to a specific pathname
+keyb.com	utility to replace ROM resident english keyboard program with
+		non-english keyboard program
+label.exe	utility to change or create a disk volume ID
+link.exe	linker 2.40 (part of the MS-DOS 3.30) product
+mode.com	utility to configure parallel and serial ports
+more.com	utility to send output to the console one screen at a time
+nlsfunc.exe	utiltiy to provide support for extended country information
+print.com	utility to print text files on a line printer
+recover.com	utility to recover disk directory
+replace.exe	utility to update previous verison on files on a disk
+restore.exe	utility to restore files that were backed up with backup.exe
+share.exe	utility to install file sharing and locking
+sort.exe	utility to read standard input, sort data and write to a device
+subst.exe	utility to substitute a string alias for a pathname
+sys.com 	utility to transfer msdos system files
+tree.com	utility to display the directory structure & contents of a drive
+xcopy.exe	utility to copy files, directories and lower level directories
+
+
+dev		    <dir>
+
+ansi.sys	installable console device driver
+country.sys	used to identify the date, time, collating sequence,
+		capitalization and folding format for a given country
+display.sys	allows use of code page switching for the display
+driver.sys	installable device driver to support external drives
+keyboard.sys	allows use of code page switch for the keyboard
+printer.sys	allows use of code page switching for the printer
+ramdrive.sys	installable RAM disk device driver
+vdisk.sys	installable RAM disk device driver
+
+src		    <dir>
+
+makefile	builds all CLONE VERSION DISTRIBUTION buildables
+
+src\bios	    <dir>
+
+biomes.inc	io.sys include file
+biostruc.inc	io.sys include file
+clocksub.inc	io.sys include file
+cmosequ.inc	io.sys include file
+dskprm.inc	io.sys include file
+jumpmac.inc	io.sys include file
+locscr		exe2bin location script
+makefile	io.sys link script
+ms96tpi.inc	io.sys include file
+msaux.asm	io.sys source file
+msbds.inc	io.sys include file
+msbio.lnk	msbio.link script
+msbio1.asm	io.sys source file
+msbio2.asm	io.sys source file
+msclock.asm	io.sys source file
+mscon.asm	io.sys source file
+msdata.inc	io.sys include file
+msdisk.asm	io.sys source file
+msequ.inc	io.sys include file
+msextrn.inc	io.sys include file
+msgroup.inc	io.sys include file
+mshard.asm	io.sys source file
+msinit.asm	io.sys source file
+msioctl.inc	io.sys include file
+msload.asm	io.sys source file
+msload.inc	io.sys include file
+mslpt.asm	io.sys source file
+msmacro.inc	io.sys include file
+msstack.inc	io.sys include file
+msvolid.inc	io.sys include file
+pushpop.inc	io.sys include file
+readcloc.inc	io.sys include file
+stkinit.inc	io.sys include file
+stkmes.inc	io.sys include file
+sysconf.asm	io.sys source file
+sysimes.asm	io.sys source file - message text
+sysimes.inc	io.sys include file
+sysinit1.asm	io.sys source file - system initialization
+sysinit2.asm	io.sys source file - system initialization
+
+
+
+src\boot	    <dir>
+
+boot.inc	msboot include file
+boot11.inc	msboot include file
+makefile	msboot make file
+messages.inc	msboot message file
+msboot.asm	msboot source file
+msboot.bin	boot sector
+
+
+
+MS-DOS 3.20 CLONE VERSION DISTRIBUTION DISKETTES	   MS320DIS02
+
+src\cmd\format	    <dir>
+
+bootmes.inc	format include file
+format.asm	format generic source file
+format.lnk	format link script
+forproc.asm	format source file
+make_inc.bas	BASIC program to establish system size - makes filesize.inc
+makefile	makefile for format.com
+messages.asm	format message source file
+messages.inc	format include file
+oemfor.asm	format OEM specific source file
+
+
+src\cmd\print	    <dir>
+
+makefile	makefile for print.com
+nprintf.asm	print source file
+pridefs.inc	print include file
+print.lnk	print link script
+print_r.asm	print resident source code
+print_rm.asm	print resident message source code
+print_rm.inc	print resident include file
+print_t.asm	print transient source code
+print_tm.asm	print transient message source code
+print_tm.inc	print transient include file
+
+
+src\cmd\sort	    <dir>
+
+makefile	make file for sort.exe
+messages.asm	sort message file
+sort.asm	sort source file
+sort.lnk	sort link response file
+
+
+src\cmd\sys	    <dir>
+
+build.bat	batch file to build sys.exe
+messages.asm	sys message file
+sys.asm 	sys source file
+sys.lnk 	sys link response file
+
+src\dos 	    <dir>
+
+abort.obj	msdos.sys object module
+alloc.obj	msdos.sys object module
+arena.inc	msdos.sys include file
+bpb.inc 	msdos.sys include file
+buf.obj 	msdos.sys object module
+buffer.inc	msdos.sys include file
+close.obj	msdos.sys object module
+const2.obj	msdos.sys object module
+cpmfcb.inc	msdos.sys include file
+cpmio.obj	msdos.sys object module
+cpmio2.obj	msdos.sys object module
+create.obj	msdos.sys object module
+crit.obj	msdos.sys object module
+curdir.obj	msdos.sys object module
+delete.obj	msdos.sys object module
+dev.obj 	msdos.sys object module
+devsym.inc	msdos.sys include file
+dinfo.obj	msdos.sys object module
+dir.obj 	msdos.sys object module
+dir2.obj	msdos.sys object module
+dircall.obj	msdos.sys object module
+dirent.inc	msdos.sys include file
+disk.obj	msdos.sys object module
+disk2.obj	msdos.sys object module
+disk3.obj	msdos.sys object module
+divmes.inc	msdos.sys include file
+doscntry.inc	msdos.sys include file
+dosmac.inc	msdos.sys include file
+dosseg.inc	msdos.sys include file
+dossym.inc	msdos.sys include file
+dpb.inc 	msdos.sys include file
+dpl.inc 	msdos.sys include file
+dup.obj 	msdos.sys object module
+error.inc	msdos.sys include file
+exe.inc 	msdos.sys include file
+fat.obj 	msdos.sys object module
+fcb.obj 	msdos.sys object module
+fcbio.obj	msdos.sys object module
+fcbio2.obj	msdos.sys object module
+file.obj	msdos.sys object module
+filemode.inc	msdos.sys include file
+find.inc	msdos.sys include file
+finfo.obj	msdos.sys object module
+getset.obj	msdos.sys object module
+handle.obj	msdos.sys object module
+intnat.inc	msdos.sys include file
+ioctl.inc	msdos.sys include file
+ioctl.obj	msdos.sys object module
+isearch.obj	msdos.sys object module
+lock.obj	msdos.sys object module
+macro.obj	msdos.sys object module
+macro2.obj	msdos.sys object module
+makefile	msdos.sys makefile
+mi.inc		msdos.sys include file
+misc.obj	msdos.sys object module
+misc2.obj	msdos.sys object module
+mknode.obj	msdos.sys object module
+msdos.lnk	msdos.sys link script
+mult.inc	msdos.sys include file
+nibdos.obj	msdos.sys object module
+open.obj	msdos.sys object module
+parse.obj	msdos.sys object module
+path.obj	msdos.sys object module
+pdb.inc 	msdos.sys include file
+proc.obj	msdos.sys object module
+rename.obj	msdos.sys object module
+rom.obj 	msdos.sys object module
+search.obj	msdos.sys object module
+sf.inc		msdos.sys include file
+share.obj	msdos.sys object module
+smdossym.inc	msdos.sys include file
+srvcall.obj	msdos.sys object module
+stdcode.obj	msdos.sys object module
+stdctrlc.obj	msdos.sys object module
+stddata.obj	msdos.sys object module
+stddisp.obj	msdos.sys object module
+stddosme.asm	msdos.sys source file
+stddosme.obj	msdos.sys object module
+stdsw.inc	msdos.sys include file
+stdtable.obj	msdos.sys object module
+syscall.inc	msdos.sys include file
+sysvar.inc	msdos.sys include file
+time.obj	msdos.sys object module
+util.obj	msdos.sys object module
+vector.inc	msdos.sys include file
+
+
+
+src\inc 	    <dir>
+
+macro.inc	general msdos include file
+struc.inc	general msdos include file
+version.inc	general msdos include file
+versiona.inc	general msdos include file
+
+
+
+src\libc	    <dir>
+
+The files in this directory are needed when linking various msdos files.
+
+cds.obj
+dpb.obj
+errtst.obj
+itoupper.obj
+join.c
+kstring.c
+printf.asm
+string.c
+sysvar.c
+
+
+tools		    <dir>
+
+The files in this directory are used to make the parts of the MSDOS product.
+None of these files(except exe2bin.exe), however are part of the MS-DOS product
+and they should not be supplied to an OEM's customers.
+
+convert.exe	special file to change certain .EXE files to .COM files
+dbof.exe	used to insure that boot record is located proper on disk
+exe2bin.exe	same as exe2bin.exe in product - it is included here as
+		as a convenience
+exefix.exe	used by some makefiles to convert .EXE files to .COM files
+gwbasic.exe	same gwbasics as in packaged procduct.	It is used by the
+		makefile in format - it is included here as a convenience
+link.exe	linker used to build msdos
+masm.exe	masm.exe from  Retail Macro Assember 4.00 Product
+masm401.exe	special masm used to build IO.SYS
+msmake.exe	make utility - renamed msmake to distinquish it from XENIX make
+
+3. Instruction for use.
+
+The MS-DOS release installation procedure is described in Chapter 3 of
+the MS-DOS 2.XX/3.XX adaptation guide.
+
+It is recommended that the DISTRIBUTION DISKETTES be copied over
+to a hard disk with the XCOPY.EXE command.  This will set up
+a directory tree that the makefiles can use properly.  All the
+buildables on the DISTRIBUTION DISKETTES can be built by setting
+the PATH to SRC\TOOLS and running the MAKEFILE in the SRC directory.
+It is important that the file be built in the order that they are
+by this makefile as there are some dependencies on former builds
+having occurred.
+
+It is also recommended that MS-DOS 3.30 is installed on the build
+machine and that the build occurs under MS-DOS 3.30.  This will
+insure that any version dependent tools will perform properly.	MS-DOS
+3.30 can be installed on the build machine by booting from the floppy
+with the boot disk from either the DISTRIBUTION DISKETTES or the PACKAGED
+PRODUCT and then using the SYS command or FORMAT /S to get the system to the
+hard disk.
+
+System Filenames are MSDOS.SYS and IO.SYS in FORMAT and SYS.
+
+FORMAT.EXE and SYS.COM have the boot sector installed with INSBIN.EXE.
+
+The OEM NUMBER is FF.
+
+Build Scripts require that the files EXE2BIN.EXE and DEBUG.EXE be in the PATH.
+
+The 8-bit OEM Serial number may be installed with DEBUG by patching MSDOS.SYS
+at location 355H (455 under DEBUG).
+
+The 24-bit OEM User number may be installed with DEBUG by patching MSDOS.SYS
+at location 352H (452 under DEBUG).
+
+SYSINIT  LINK REQUIREMENTS.
+
+    SYSINIT1.obj now requires an external FAR routine called StackInit
+    to be linked.  This routine has available to it the parameters
+
+	    STACK_ADDR:  DWORD
+	    STACK_SIZE:  WORD
+	    STACK_COUNT: WORD
+
+
+    StackInit initializes the Stack Heap and corresponding interrupt
+    vectors used to handle potential hardware driven stack overflows.
+    After completing its task, StackInit issues a RETF to return to
+    SYSINIT1.
+	       To use the IBM compatible SYSINIT1, the OEM must
+    provide the FAR ROUTINE StackInit, whose only task is to issue a
+    RETF.
+
+
+The CONVERT utility is provided in the TOOLS directory to
+rename certain .EXE utilties as .COM files if desired.	The CONVERT utility
+is not part of the MS-DOS product and should be used only as
+described as follows:
+
+
+Documentation for CONVERT.EXE
+
+CONVERT is used by entering CONVERT and an .EXE file name (with the .EXE
+extension).
+
+CONVERT FOO.EXE
+
+	will build a FOO.COM file
+
+
+CONVERT adds an .EXE loader onto the .EXE file image
+
+It should not be confused with EXE2BIN.EXE
+
+These are the differences:
+
+EXE2BIN
+
+   - EXE2BIN is a utility for converting .EXE files to binary (.COM).
+
+   - EXE2BIN produces a .COM file which is smaller than the .EXE file.
+
+   - EXE2BIN may only convert files conforming to a certain documented set of
+     requirements.
+
+   - EXE2BIN can only be used on a file written as .COM file (ORG 100h, not
+     stack segment).
+
+
+CONVERT
+
+   - CONVERT transforms an .EXE file into a .COM file by appending the
+     MS-DOS loader to the end of the file.
+
+   - A CONVERTed file will be larger than an equivalent .EXE file.
+
+   - CONVERT will convert ANY .EXE program.
+
+   - CONVERT should only be used in UNUSUAL circumstances, such as when
+     an application program demands that a file have a .COM extension.
+
+
+
+4. Differences in the files in the MS VERSION and CLONE VERSION of MS-DOS
+
+This is a complete list of the differences between the MS VERSION and the
+CLONE VERSION of MS-DOS at the 3.XX level.  It is intended to illustrate how
+few the differences actually are.  These differences occur as a result of
+conditional assemblies based on whether MSVER or IBMVER is TRUE at the time
+of assembly.
+
+		CLONE VERSION			      MS VERSION
+DOS
+==================================================================
+
+OEM_HANDLER	OEM_HANDLER code	       OEM_HANDLER code
+		for call F8 NOT included       for call F8 included
+
+DOS header	IBM Text			MSDOS text
+
+Print of DOS	NO				YES
+  version at
+  boot time
+
+INT 25,26 AH	YES				NO
+  error code
+  mapping
+
+International	Large set			US table only
+  tables
+
+Case map call	IBM PC specific 		None
+  in internat
+  tables
+
+Function Key	IBM PC				Z-19 (Zenith terminal)
+  definition
+
+^N defined as	NO				YES
+  special char
+  equivalent
+  to ^P
+
+******************************************************************
+
+		CLONE VERSION			      MS VERSION
+SHARE
+==================================================================
+
+     NOTE: The MS VERSION and CLONE VERSION  do have minor
+	   differences and will not file compare.  The differences
+	   have to do with the DOS data modules linked in with SHARE.
+	   The CLONE VERSION SHARE, MSDOS and REDIR should be used only with
+	   each other and the MS VERSION SHARE, MSDOS and REDIR should be
+	   used only with each other.
+
+*****************************************************************************
+
+		CLONE VERSION			      MS VERSION
+COMMAND
+==================================================================
+
+CLS		Special IBM code to detect	Assumes ANSI support,
+		if ANSI driver installed.	outputs ANSI CLS sequence.
+		If no ANSI driver, CLS done
+		by direct calls to INT 10H
+
+ROM exec	Special code for PC-Jr ROM	No ROM exec code
+		cartridges.
+
+
+*****************************************************************************
+
+		CLONE VERSION			      MS VERSION
+PRINT
+==================================================================
+		INT 17,13,14,5,15 handlers	No special handlers
+
+		IBM specific timer int code	No timer int code
+
+	NOTE: SOURCE CODE FOR PRINT IS SENT SO THAT
+		OEMs CAN PORT THEM TO THEIR MACHINES.
+
+	NOTE: SETTING THE IBM SWITCHES TO TRUE IN PRINT
+		WILL NOT YIELD A BINARY THAT IS THE SAME AS THE IBM
+		3.2 .
+
+		In PRINT's case this is due to some slight code
+		re-organization that was needed to get a valid
+		PRINT with the IBM switches set to FALSE.
+
+
+*****************************************************************************
+
+		CLONE VERSION			      MS VERSION
+DEBUG
+==================================================================
+INT controler	Contains code to twiddle	No code included
+		one of the 8259 interrupt
+		controller registers to
+		fix the trace of the timer
+		int problems
+
+Screen Width	Issues INT 10H to get		Assumes screen is at
+		screen width.			least 80 column
+
+*****************************************************************************
+
+		CLONE VERSION			      MS VERSION
+FORMAT
+==================================================================
+			MS VERSION CLONE VERSION
+			ARE IDENTICAL
+
+*****************************************************************************
+
+		CLONE VERSION			      MS VERSION
+SYS
+==================================================================
+
+Put Boot	Contains Boot sector		No put boot code
+		output code to put
+		correct boot sectors
+		on SYSed disks
+
+Check for valid Uses INT 25 to make sure	Minimal checking of
+destination	that destination disk is	MSDOS.SYS size
+		empty or has correct IBM
+		bootable disk format
+
+*****************************************************************************
+
+		CLONE VERSION			      MS VERSION
+RECOVER
+==================================================================
+ROM COM AREA	Twiddles a byte in the ROM	No code
+TWIDDLE 	communication area on single
+		drive systems to indicate
+		drive changed.
+
+*****************************************************************************
+
+		CLONE VERSION			      MS VERSION
+EXE2BIN
+==================================================================
+			MS VERSION CLONE VERSION
+			ARE IDENTICAL
+
+*****************************************************************************
+
+		CLONE VERSION			      MS VERSION
+CHKDSK
+==================================================================
+			MS VERSION CLONE VERSION
+			ARE IDENTICAL
+
+*****************************************************************************
+
+		CLONE VERSION			      MS VERSION
+FIND
+==================================================================
+			MS VERSION CLONE VERSION
+			ARE IDENTICAL
+
+*****************************************************************************
+
+		CLONE VERSION			      MS VERSION
+ASSIGN
+==================================================================
+			MS VERSION CLONE VERSION
+			ARE IDENTICAL
+
+*****************************************************************************
+
+		CLONE VERSION			      MS VERSION
+ATTRIB
+==================================================================
+			MS VERSION CLONE VERSION
+			ARE IDENTICAL
+
+*****************************************************************************
+
+		CLONE VERSION			      MS VERSION
+SUBST
+==================================================================
+			MS VERSION CLONE VERSION
+*			 ARE IDENTICAL
+
+*****************************************************************************
+
+		CLONE VERSION			      MS VERSION
+JOIN
+==================================================================
+			MS VERSION CLONE VERSION
+			ARE IDENTICAL
+
+*****************************************************************************
+
+		CLONE VERSION			      MS VERSION
+EDLIN
+==================================================================
+			MS VERSION CLONE VERSION
+			ARE IDENTICAL
+
+*****************************************************************************
+
+		CLONE VERSION			      MS VERSION
+MORE
+==================================================================
+Screen Width	Issues INT 10H to get		Assumes screen is
+		width of screen 		at least 80 column
+
+Non printing	Assumes all chars < 20H 	Assumes chars < 20H
+chars		except for BELL (07) are	are non printing and
+		printing characters which	do not advance the
+		advance the cursor one		cursor if output
+		position if output.
+
+*****************************************************************************
+
+		CLONE VERSION			      MS VERSION
+SORT
+==================================================================
+Internat chars	Defines coalating sequence	Chars > 7FH are sorted
+		for some chars > 7FH approp	in value order
+		to IBM international char
+		sets
+
+*****************************************************************************
+
+		CLONE VERSION			      MS VERSION
+BIOS (SYSINIT)
+==================================================================
+MEM scan	Mem scan code not included	Includes memory scan
+		Assumes BIOS sets memory	code if OEM BIOS
+		size variable always.		does not set memory
+						size variable.

SRC/BIOS/BIOMES.INC

@@ -0,0 +1,31 @@
+
+							;;Rev 3.30 Modification
+; SINGLE DRIVE MESSAGE FOR BIOS. NUL TERMINATED.			  
+IFNDEF	PATHSTART							  
+PATHSTART MACRO INDEX,ABBR						  
+	IFDEF	PATHGEN 						  
+	    PUBLIC  ABBR&INDEX&S,ABBR&INDEX&E				  
+	    ABBR&INDEX&S LABEL	 BYTE					  
+	ENDIF								  
+	ENDM								  
+ENDIF									  
+									  
+IFNDEF	PATHEND 							  
+PATHEND MACRO	INDEX,ABBR						  
+	IFDEF	PATHGEN 						  
+	    ABBR&INDEX&E LABEL	 BYTE					  
+	ENDIF								  
+	ENDM								  
+ENDIF									  
+									  
+	PATHSTART 001,BIOMS						  
+									  
+;
+; Single drive message for msbio.com. Nul terminated.	;;End of Modification
+;
+
+SNGMSG	DB	CR,LF,"Insert diskette for drive "
+DRVLET	DB	"A: and strike",CR,LF,"any key when ready",CR,LF,LF,0
+
+	PATHEND 001,BIOMS
+

SRC/BIOS/BIOSTRUC.INC

@@ -0,0 +1,87 @@
+
+
+						  ;;Rev 3.30 Modification
+; ROM BIOS CALL PACKET STRUCTURES					  
+									  
+;*******************************					  
+;System Service call ( Int 15h )					  
+;*******************************					  
+;Function AH = 0C0h, Return system configuration			  
+;For PC and PCJR on return:						  
+;	(AH)	= 80h							  
+;	(CY)	= 1							  
+;For PCXT, PC PORTABLE and PCAT on return:				  
+;	(AH)	= 86h							  
+;	(CY)	= 1							  
+;For all others:							  
+;	(AH)	= 0							  
+;	(CY)	= 0							  
+;	(ES:BX) = pointer to system descriptor vector in ROS		  
+; System descriptor :							  
+;	DW	xxxx		length of descriptor in bytes,		  
+;				minimum length = 8			  
+;	DB	xx		model byte				  
+;				0FFh	= PC				  
+;				0FEh	= PC/XT, Portable		  
+;				0FDh	= PC/JR 			  
+;				0FCh	= PC/AT				  
+;				0F9h	= Convertable			  
+;				0F8h	= Model 80			  
+;				0E0 thru 0EFh = reserved		  
+;									  
+;	DB	xx		secondary model byte			  
+;				000h	= PC1				  
+;				000h	= PC/XT, Portable		  
+;				000h	= PC/JR 			  
+;				000h	= PC/AT 			  
+;				001h	= PC/AT Model 339		  
+;				003h	= PC/RT				  
+;				000h	= Convertable			  
+;									  
+;	DB	xx		bios revision level			  
+;				00 for first release, subsequent release  
+;				of code with same model byte and	  
+;				secondary model byte require revison level
+;				to increase by one.			  
+;									  
+;	DB	xx		feature information byte 1		  
+;				X0000000 = 1, bios use DMA channel 3	  
+;					 = 0, DMA channel 3 not used	  
+;									  
+;				0X000000 = 1, 2nd Interrupt chip present  
+;					 = 0, 2nd Interrupt chip not present
+;									  
+;				00X00000 = 1, Real Time Clock present	  
+;					 = 0, Real Time Clock not present 
+;									  
+;				000X0000 = 1, Keyboard escape sequence(INT 15h)
+;						called in keyboard interrupt
+;						(Int 09h).		  
+;					 = 0, Keyboard escape sequence not
+;						called. 		  
+;				0000XXXX reserved			  
+;									  
+;	DB	xx		feature information byte 2 - reserved	  
+;									  
+;	DB	xx		feature information byte 2 - reserved	  
+;									  
+;	DB	xx		feature information byte 2 - reserved	  
+;									  
+;	DB	xx		feature information byte 2 - reserved	  
+;									  
+									  
+BIOS_SYSTEM_DESCRIPTOR	struc						  
+bios_SD_leng		dw	?					  
+bios_SD_modelbyte	db	?					  
+bios_SD_scnd_modelbyte	db	?					  
+			db	?					  
+bios_SD_featurebyte1	db	?					  
+			db   4 dup (?)					  
+BIOS_SYSTEM_DESCRIPTOR ends						  
+									  
+;FeatureByte1	bit map equates 					  
+DMAchannel3		equ 10000000b					  
+ScndIntController	equ 01000000b					  
+RealTimeClock		equ 00100000b					  
+KeyEscapeSeq		equ 00010000b					  
+						;;End of Modification									  

SRC/BIOS/CLOCKSUB.INC

@@ -0,0 +1,76 @@
+
+;
+;   date_verify loosely checks bcd date values to be in range in bin_date_time
+;
+date_verify:				    ;
+	cmp	byte ptr bin_date_time+0,20h  ; century check
+	ja	date_error		    ; jmp error
+	jz	century_20		    ; jmp in 20th century
+	cmp	byte ptr bin_date_time+0,19h  ; century check
+	jb	date_error		    ; jmp error
+	cmp	byte ptr bin_date_time+1,80h  ; year check
+	jb	date_error		    ; jmp error
+century_20:				    ;
+	cmp	byte ptr bin_date_time+1,99h  ; year check
+	ja	date_error		    ; jmp error
+	cmp	byte ptr bin_date_time+2,12h  ; month check
+	ja	date_error		    ; jmp error
+	cmp	byte ptr bin_date_time+2,00h  ; month check
+	jbe	date_error		    ; jmp error
+	cmp	byte ptr bin_date_time+3,31h  ; day check
+	ja	date_error		    ; jmp error
+	cmp	byte ptr bin_date_time+3,00h  ; day check
+	jbe	date_error		    ; jmp error
+	clc				    ; set success flag
+	ret				    ;
+date_error:				    ;
+	stc				    ; set error flag
+	ret				    ;
+
+;
+; time_verify very loosely checks bcd date values to be in range in bin_date_time
+;
+time_verify:
+	cmp	byte ptr bin_date_time+0,24H
+	ja	time_error
+	cmp	byte ptr bin_date_time+1,59H
+	ja	time_error
+	cmp	byte ptr bin_date_time+2,59H
+	ja	time_error
+	clc
+	ret
+time_error:
+	stc
+	ret
+
+;
+;   bcd_verify checks values in bin_date_time to be valid
+;   bcd numerals.  carry set if any nibble out of range
+;
+bcd_verify:			;
+	mov	cx,4		; 4 bytes to check
+	mov	bx,offset bin_date_time   ;
+bv_loop:			;
+	mov	al,[bx] 	; get a bcd number (0..99)
+	mov	ah,al		;
+	and	ax,0f00fh	; 10's place in high ah, 1's in al
+	cmp	al,10		; is 1's place in range?
+	ja	bv_error	; jmp out of range
+	shr	ah,1		; swap nibbles
+	shr	ah,1		; ...
+	shr	ah,1		; ...
+	shr	ah,1		; ...
+	and	ah,0fh		; get rid of any erroneous bits
+	cmp	ah,10		; is 10's place in range
+	ja	bv_error	; jmp out of range
+	inc	bx		; next byte
+	dec	cx		;
+	jnz	bv_loop 	;
+	clc			; set success flag
+	ret			;
+bv_error:			;
+	stc			; set error flag
+	ret			;
+;
+; Dos 3.30 - The real time clock structures were moved to msbio2.asm
+;

SRC/BIOS/CMOSEQU.INC

@@ -0,0 +1,50 @@
+							 ;;Rev 3.30 Modification
+;Equates for CMOS.							   
+									  
+;----------------------------------------				  
+;	CMOS EQUATES FOR THIS SYSTEM	:				  
+;------------------------------------------------------------------------------- 
+CMOS_PORT	EQU	070H		; I/O ADDRESS OF CMOS ADDRESS PORT	 
+CMOS_DATA	EQU	071H		; I/O ADDRESS OF CMOS DATA PORT 	 
+NMI		EQU	10000000B	; DISABLE NMI INTERRUPTS MASK - 	 
+					;  HIGH BIT OF CMOS LOCATION ADDRESS	 
+										 
+;---------- CMOS TABLE LOCATION ADDRESS'S ## ----------------------------------- 
+CMOS_SECONDS	EQU	000H		; SECONDS				 
+CMOS_SEC_ALARM	EQU	001H		; SECONDS ALARM  ## NOTE:  ALL LOCATIONS 
+CMOS_MINUTES	EQU	002H		; MINUTES	      | IN THE CMOS AREA 
+CMOS_MIN_ALARM	EQU	003H		; MINUTES ALARM       | ARE IBM USE ONLY 
+CMOS_HOURS	EQU	004H		; HOURS 	      | AND  SUBJECT  TO 
+CMOS_HR_ALARM	EQU	005H		; HOURS ALARM	      | CHANGE. ONLY THE 
+CMOS_DAY_WEEK	EQU	006H		; DAY OF THE WEEK     | POST & BIOS CODE 
+CMOS_DAY_MONTH	EQU	007H		; DAY OF THE MONTH    | SHOULD	DIRECTLY 
+CMOS_MONTH	EQU	008H		; MONTH 	      | ACCESS LOCATIONS 
+CMOS_YEAR	EQU	009H		; YEAR (TWO DIGITS)   | IN CMOS STORAGE. 
+CMOS_REG_A	EQU	00AH		; STATUS REGISTER A   '----------------- 
+CMOS_REG_B	EQU	00BH		; STATUS REGISTER B  ALARM		 
+CMOS_REG_C	EQU	00CH		; STATUS REGISTER C  FLAGS		 
+CMOS_REG_D	EQU	00DH		; STATUS REGISTER D  BATTERY		 
+CMOS_DIAG	EQU	00EH		; POST DIAGNOSTIC STATUS RESULTS BYTE	 
+CMOS_SHUT_DOWN	EQU	00FH		; SHUTDOWN STATUS COMMAND BYTE		 
+CMOS_DISKETTE	EQU	010H		; DISKETTE DRIVE TYPE BYTE	      ;  
+;		EQU	011H		; - RESERVED			      ;C 
+CMOS_DISK	EQU	012H		; FIXED DISK TYPE BYTE		      ;H 
+;		EQU	013H		; - RESERVED			      ;E 
+CMOS_EQUIP	EQU	014H		; EQUIPMENT WORD LOW BYTE	      ;C 
+CMOS_B_M_S_LO	EQU	015H		; BASE MEMORY SIZE - LOW BYTE (X1024) ;K 
+CMOS_B_M_S_HI	EQU	016H		; BASE MEMORY SIZE - HIGH BYTE	      ;S 
+CMOS_E_M_S_LO	EQU	017H		; EXPANSION MEMORY SIZE - LOW BYTE    ;U 
+CMOS_E_M_S_HI	EQU	018H		; EXPANSION MEMORY SIZE - HIGH BYTE   ;M 
+CMOS_DISK_1	EQU	019H		; FIXED DISK TYPE - DRIVE C EXTENSION ;E 
+CMOS_DISK_2	EQU	01AH		; FIXED DISK TYPE - DRIVE D EXTENSION ;D 
+;		EQU	01BH		; - 1BH THROUGH 2DH - RESERVED	      ;  
+CMOS_CKSUM_HI	EQU	02EH		; CMOS CHECKSUM - HIGH BYTE	      ;* 
+CMOS_CKSUM_LO	EQU	02FH		; CMOS CHECKSUM - LOW BYTE	      ;* 
+CMOS_U_M_S_LO	EQU	030H		; USABLE MEMORY ABOVE 1 MEG - LOW BYTE	 
+CMOS_U_M_S_HI	EQU	031H		; USABLE MEMORY ABOVE 1 MEG - HIGH BYTE  
+CMOS_CENTURY	EQU	032H		; DATE CENTURY BYTE (BCD)		 
+CMOS_INFO128	EQU	033H		; 128KB INFORMATION STATUS FLAG BYTE	 
+;		EQU	034H		; - 34H THROUGH 3FH - RESERVED		 
+;										 
+							;;End of Modification									 
+

SRC/BIOS/DSKPRM.INC

@@ -0,0 +1,22 @@
+; The following structure defines the disk parameter table
+; pointed to by Interrupt vector 1EH (location 0:78H)
+
+DISK_PARMS	STRUC
+DISK_SPECIFY_1	DB	?
+DISK_SPECIFY_2	DB	?
+DISK_MOTOR_WAIT DB	?	; Wait till motor off
+DISK_SECTOR_SIZ DB	?	; Bytes/Sector (2 = 512)
+DISK_EOT	DB	?	; Sectors per track (MAX)
+DISK_RW_GAP	DB	?	; Read Write Gap
+DISK_DTL	DB	?
+DISK_FORMT_GAP	DB	?	; Format Gap Length
+DISK_FILL	DB	?	; Format Fill Byte
+DISK_HEAD_STTL	DB	?	; Head Settle Time (MSec)
+DISK_MOTOR_STRT DB	?	; Motor start delay
+DISK_PARMS	ENDS
+
+ROMStatus	equ	1
+ROMRead 	equ	2
+ROMWrite	equ	3
+ROMVerify	equ	4
+ROMFormat	equ	5

SRC/BIOS/JUMPMAC.INC

@@ -0,0 +1,32 @@
+
+						  ;;Rev 3.30 Modification
+;
+; given a label <lbl> either 2 byte jump to another label <lbl>_J
+; if it is near enough or 3 byte jump to <lbl>
+;
+
+jump	macro lbl
+	local a
+.xcref
+
+	ifndef lbl&_j			;; is this the first invocation
+a:
+				JMP lbl
+	ELSE
+	    IF (lbl&_J GE $) OR ($-lbl&_J GT 126)
+a:
+				JMP lbl ;; is the jump too far away?
+	    ELSE
+a:
+			       JMP lbl&_J  ;; do the short one...
+	    ENDIF
+	ENDIF
+lbl&_j = a
+.cref
+	endm
+.xcref	jump
+;REDEFINE THE ABOVE MACRO TO ALWAYS TRY A 3 BYTE NEAR JUMP		 
+JUMP MACRO LBL								 
+					JMP LBL 			 
+	ENDM					;;End of Modification
+

SRC/BIOS/LOCSCR

@@ -0,0 +1 @@
+70

SRC/BIOS/MAKEFILE

@@ -0,0 +1,107 @@
+#***	Makefile for BIOS
+
+DEST	=io
+MSG	=messages
+DOS	=..\dos
+
+#	Definitions for Assembler
+
+ASM	=masm
+AFLAGS	=-Mx -t
+AINC	=-I. -I..\inc -I$(DOS)
+
+#	Definitions for C compiler
+
+CC	=cl
+CFLAGS	=-Ox -X -Zlp
+CINC	=-I. -I..\h
+
+#	Definitions for Linker
+
+LINK	=link
+
+#	Built-in rules
+
+.asm.obj:
+	$(ASM) $(AFLAGS) $(AINC) $*.asm,$*.obj;
+
+.asm.lst:
+	$(ASM) -l $(AFLAGS) $(AINC) $*.asm;
+
+.c.obj:
+	$(CC) -c $(CFLAGS) $(CINC) -Fo$*.obj $*.c
+
+.c.lst:
+	$(CC) -c $(CFLAGS) $(CINC) -Fc$*.cod -Fo$*.obj $*.c
+
+.exe.com:
+	reloc $*.exe $*.com
+
+#	Dependencies
+
+msload.obj: msload.asm msload.inc
+
+msload.com: msload.obj
+	LINK msload.obj,msload,,;
+	exe2bin msload.exe msload.com
+	del msload.exe
+
+msbio1.obj: msbio1.asm msdata.inc msgroup.inc jumpmac.inc pushpop.inc \
+   $(DOS)\devsym.inc dskprm.inc msmacro.inc
+
+
+mscon.obj: mscon.asm msgroup.inc jumpmac.inc msmacro.inc
+
+msaux.obj: msaux.asm msgroup.inc jumpmac.inc msmacro.inc
+
+mslpt.obj: mslpt.asm msgroup.inc msequ.inc msbds.inc msmacro.inc \
+   $(dos)\devsym.inc $(dos)\ioctl.inc $(dos)\bpb.inc
+
+msclock.obj: msclock.asm msgroup.inc  msmacro.inc
+
+msdisk.obj: msdisk.asm msgroup.inc msequ.inc msbds.inc pushpop.inc \
+   msmacro.inc $(dos)\devsym.inc dskprm.inc msioctl.inc \
+   $(dos)\ioctl.inc $(dos)\bpb.inc
+
+msinit.obj: msinit.asm msgroup.inc dskprm.inc msequ.inc msbds.inc \
+   msmacro.inc readclock.inc clocksub.inc msextrn.inc
+
+sysinit1.obj: sysinit1.asm msstack.inc stkmes.inc stkinit.inc \
+   $(dos)\devsym.inc $(dos)\ioctl.inc $(dos)\smdossym.inc \
+   $(dos)\dosmac.inc $(dos)\bpb.inc $(dos)\buffer.inc \
+    $(dos)\sysvar.inc $(dos)\vector.inc $(dos)\dirent.inc \
+    $(dos)\dpb.inc $(dos)\curdir.inc $(dos)\pdb.inc $(dos)\exe.inc \
+    $(dos)\sf.inc $(dos)\arena.inc $(dos)\intnat.inc $(dos)\mi.inc \
+    $(dos)\syscall.inc
+	masm401 $(AFLAGS) $(AINC) sysinit1;
+
+sysconf.obj: sysconf.asm $(dos)\devsym.inc $(dos)\ioctl.inc \
+    $(dos)\smdossym.inc $(dos)\dosmac.inc $(dos)\bpb.inc $(dos)\buffer.inc \
+    $(dos)\sysvar.inc $(dos)\vector.inc $(dos)\dirent.inc \
+    $(dos)\dpb.inc $(dos)\curdir.inc $(dos)\pdb.inc $(dos)\exe.inc \
+    $(dos)\sf.inc $(dos)\arena.inc $(dos)\intnat.inc $(dos)\mi.inc \
+    $(dos)\syscall.inc
+
+sysinit2.obj: sysinit2.asm $(dos)\devsym.inc $(dos)\ioctl.inc \
+    $(dos)\smdossym.inc $(dos)\dosmac.inc $(dos)\bpb.inc $(dos)\buffer.inc \
+    $(dos)\sysvar.inc $(dos)\vector.inc $(dos)\dirent.inc \
+    $(dos)\dpb.inc $(dos)\curdir.inc \
+    $(dos)\pdb.inc $(dos)\exe.inc $(dos)\sf.inc $(dos)\arena.inc \
+    $(dos)\intnat.inc $(dos)\mi.inc $(dos)\syscall.inc
+
+sysimes.obj: sysimes.asm msmacro.inc sysimes.inc msequ.inc msbds.inc
+
+msbio2.obj: msbio2.asm msgroup.inc msequ.inc msbds.inc $(dos)\devsym.inc \
+   pushpop.inc msmacro.inc biomes.inc ms96tpi.inc msvolid.inc
+
+mshard.obj: mshard.asm
+
+msbio.bin: msbio1.obj mscon.obj  msaux.obj mslpt.obj msclock.obj \
+   msdisk.obj msbio2.obj msinit.obj mshard.obj sysinit1.obj \
+   sysconf.obj sysinit2.obj sysimes.obj
+	link @msbio.lnk
+	exe2bin msbio.exe msbio.bin < locscr
+	copy /b msload.com+msbio.bin io.sys
+	del msbio.bin
+	del msbio.exe
+	del msload.com

SRC/BIOS/MS96TPI.INC

@@ -0,0 +1,494 @@
+
+;------------------------------------------------------------------------
+;									:
+; File: ms96tpi.asm							:
+;									:
+; This file contains code to support the 96 tpi drives.  The code	:
+; is included in the bio if the machine has at least one drive with	:
+; changeline support.  If the machine has no changeline drives then	:
+; the code is not kept in the bio at system initialization time.	:
+;									:
+;------------------------------------------------------------------------
+
+
+;------------------------------------------------------------------------
+;									:
+;		DISK OPEN/CLOSE ROUTINES				:
+;									:
+;------------------------------------------------------------------------
+
+DSK$OPEN:
+	PUBLIC	DSK$OPEN
+	Message fTestDisk,<"Disk Open ">        ; print debug messages
+	MNUM	fTestDisk,AX
+	Message fTestDisk,<CR,LF>
+						; AL is logical drive
+	call	SetDrive			; Get BDS for drive
+	inc	WORD PTR ds:[di].opcnt
+	jmp	EXIT
+
+DSK$CLOSE:
+	PUBLIC	DSK$CLOSE
+	Message fTestDisk,<"Disk Close ">       ; print debug messages
+	MNUM	fTestDisk,AX
+	Message fTestDisk,<CR,LF>
+						; AL is logical drive
+	call	SetDrive			; Get BDS for drive
+	cmp	WORD PTR ds:[di].opcnt,0
+	jz	EXITJX				; Watch out for wrap
+	dec	WORD PTR ds:[di].opcnt
+EXITJX:
+	jmp	EXIT
+
+;
+; ChkOpCnt checks the number of open files on drive.
+;
+; Input : DS:DI points to current BDS for drive.
+;
+; Return : zero set if no open files
+;	   zero reset if open files
+;
+
+ChkOpCnt:
+	Message fTest96,<"Check open count ">   ; print debug messages
+	MNUM	fTest96,AX
+	Message fTest96,<CR,LF>
+	cmp	WORD PTR ds:[di].opcnt,0
+	ret
+
+;
+; At media check time, we need to really get down and check what the change is.
+; This is GUARANTEED to be expensive.
+;
+; On entry AL contains logical drive number
+;
+
+	public mediacheck
+MediaCheck:
+	call	CheckSingle		; make sure correct disk is in place
+	xor	SI,SI
+	call	HasChange
+	jz	MediaRet
+	call	CheckROMChange
+	jnz	MediaDoVOLID
+	push	AX
+	push	DX
+					; see if changeline has been triggered
+;;Rev 3.30 Modification
+	mov	DL, DS:[DI.drivenum]    ; set logical drive number	  
+	mov	AH, 16h 	    ; get changeline status	  
+	int	13h		    ; call rom diskette routine	  
+;;End of Modification
+	pop	DX
+	pop	AX
+	jc	MediaDoVolid		; if changeline was triggered jmp
+	mov	SI,1			; else signal no change
+
+
+; There are some drives with changeline that "lose" the changeline indication
+; if a different drive is accessed after the current one. In order to avoid
+; missing a media change, we return an "I don't know" to DOS if the changeline
+; is not active AND we are accessing a different drive from the last one.
+; If we are accessing the same drive, then we can safely rely on the changeline
+; status.
+
+	PUBLIC LOSECHNG
+LOSECHNG:
+	mov	bl,cs:[Tim_Drv] 	; get last drive accessed
+	cmp	byte ptr [di].DriveNum,bl
+	jz	MediaRet
+; Do the 2 second twiddle. If time >= 2 seconds, do a volid check.
+; Otherwise return "I don't know" (Strictly speaking, we should return a
+; "Not Changed" here since the 2 second test said no change.) - RS.
+
+	SaveReg <AX,CX,DX>
+	call	Check_Time_Of_Access
+	RestoreReg <DX,CX,AX>
+	or	si,si
+	jz	MediaDoVolid		; Check_Time says ">= 2 secs passed"
+	xor	si,si			; return "I don't know"
+	Public MediaRet
+MediaRet:
+	ret
+
+
+;
+; MediaDoVolid:  if this is called somehow the media was changed.  Look at
+; VID to see. We do not look at FAT because this may be different since we
+; only set MedByt when doing a READ or WRITE.
+;
+
+MediaDoVolid:
+	call	GETBP		       ; build a new BPB in current BDS
+	jc	MediaRet
+	call	Check_VID
+	jnc	MediaRet
+	call	MapError		; fix up AL for return to DOS
+	ret
+
+;
+; Checklatchio:
+;
+; Simple, quick check of latched change.  If no indication, then return
+; otherwise do expensive check.  If the expensive test fails, POP off the
+; return and set AL = 15 (for invalid media change) which will be returned to
+; DOS.
+;
+	public checklatchio
+CheckLatchIO:
+; If returning fake BPB then assume the disk has not changed
+;	test	word ptr ds:[di].flags, RETURN_FAKE_BPB
+;	jnz	CheckRet
+;;Rev 3.30 Modification
+	call	HasChange		;change line supported?
+	jz	CheckRet		;No. Just return
+;;End of Modification
+	call	ChkOpCnt
+	jnz	CheckROM
+CheckRet:
+	ret
+;
+; Check for past ROM indications.  If no ROM change indicated, then return OK.
+;
+	public checkrom
+CheckROM:
+	call	CheckROMChange
+	jz	CheckRet		; no change
+;
+; We now see that a change line has been seen in the past.  Let's do the
+; expensive verification.
+;
+	Message fTest96,<"CheckROMChange says yes...",CR,LF>
+	call	GETBP			; build BPB in current BDS
+	jc	Ret_No_Error_Map	; GETBP has already called MapError
+	call	Check_VID
+	jc	CheckLatchRet		; disk error trying to read in.
+	or	SI,SI			; Is changed for sure?
+	jns	CheckRet
+	call	ReturnVid
+CheckLatchRet:
+	call	MapError		; fix up AL for return to DOS
+Ret_No_Error_Map:
+	stc				; indicate an error
+	pop	si			; pop off return address
+	ret
+
+
+
+;
+;  CheckFatVID:
+;
+; Check the FAT and the VID.  Return in DI -1 or 0.  Return with carry set
+; ONLY if there was a disk error.  Return that error code in AX.
+;
+	public checkfatvid
+CheckFATVID:
+	Message fTest96,<"Check FAT",CR,LF>
+	call	FAT_Check
+	or	SI,SI
+	js	Changed_Drv
+;
+; The fat was the same.  How about the volume ID?
+;
+Check_VID:
+	Message fTest96,<"Check VID",CR,LF>
+	call	Read_volume_ID
+	jc	CheckFatRet
+	call	Check_Volume_id
+	or	SI,SI
+	jnz	Changed_Drv
+	Message fTest96,<"VID not changed",CR,LF>
+	call	ResetChanged
+CheckFatRet:
+	ret
+Changed_Drv:
+	mov	cs:[Tim_Drv],-1 	; Ensure that we ask ROM for media
+	ret				; check next time round
+
+
+
+
+;
+; CheckIO:  At I/O time the rom-bios returned an error.  We need to
+; determine if the error is due to a media change.  If error code is not
+; change-line error (06h) we just return.  We pop off the call and jmp to
+; harderr if we see an error.
+;
+;   On entry:  AH contains error code returned from rom-bios.
+;
+
+	public checkio
+CheckIO:
+	cmp	AH,06			; change line error?
+	jnz	CheckFatRet		; no - just return
+	call	ChkOpCnt
+	jz	CheckFATRet		; no open files
+; If returning fake BPB then ignore disk changes
+;	test	word ptr ds:[di].flags, RETURN_FAKE_BPB
+;	jnz	IgnoreChange
+	call	GETBP			; build up a new BPB in current BDS
+	jc	No_Error_Map		; GETBP has already called MapError
+	call	CheckFATVID
+	jc	CheckIORet		; disk error trying to read in.
+	or	SI,SI			; Is changed for sure?
+	js	CheckIOErr		; yes changed
+IgnoreChange:
+	inc	BP			; allow a retry
+	ret
+CheckIOErr:
+	call	ReturnVid
+CheckIORet:
+	stc				; make sure carry gets passed through
+	jmp	HardErr
+
+No_Error_Map:
+	jmp	HardErr2
+
+
+
+
+;
+; Return VID sets up the VID for a return to DOS.
+;
+
+	Public ReturnVID
+ReturnVID:
+	Message fTest96,<"Return VID",cr,lf>
+	push	DS			; save pointer to current BDS
+	push	di
+	push	cx
+	call	init_vid_loop		; Sets ES:DI -> vid
+	lds	BX,cs:[PTRSAV]
+	mov	[BX.EXTRA],DI
+	mov	[BX.EXTRA+2],ES
+	pop	cx
+	pop	di			; restore current BDS
+	pop	DS
+;;	MOV	AH,6			; INVALID MEDIA CHANGE
+	mov	AH, 0Fh 		; set error as 'invalid media change'
+	stc				; indicate error by setting carry flag
+	ret
+
+;
+; Media_Set_VID:
+;
+; Moves the pointer to the volid for the drive into the original request packet
+; On entry, DS:BX points to the original packet.
+; No attempt is made to preserve registers.
+;
+
+MEDIA_SET_VID:
+	PUBLIC MEDIA_SET_VID						  ;;Rev 3.30 Modification
+	call	init_vid_loop		; Sets ES:DI -> vid		  ;;End of Modification
+	lds	bx,cs:[PtrSav]		; get pointer to packet
+	mov	word ptr [BX.TRANS+1],DI
+	mov	word ptr [BX.TRANS+3],ES
+	ret
+
+
+;
+;   HiDensity - examine a drive/media descriptor to set the media type.  If
+;   the media descriptor is NOT F9 (not 96tpi or 3 1/2), we return and let the
+;   caller do the rest.  Otherwise, we pop off the return and jump to the tail
+;   of GETBP. For 3.5" media, we just return.
+;
+;   Inputs:	DS:DI point to correct BDS for this drive
+;		AH has media byte
+;
+;   Outputs:	Carry clear
+;		    No registers modified
+;		Carry set
+;		    AL = sectors/fat
+;		    BH = number of root directory entries
+;		    BL = sectors per track
+;		    CX = number of sectors
+;		    DH = sectors per allocation unit
+;		    DL = number of heads
+;
+hidensity:
+	PUBLIC HIDENSITY						  ;;Rev 3.30 Modification
+									  ;;End of Modification
+; Check for correct drive
+;
+	test	word ptr ds:[di].flags,fChangeline	; is it special?
+	jz	DoFloppy		; no, do normal floppy test
+;
+; We have a media byte that is pretty complex.	Examine drive information
+; table to see what kind it is.
+;
+	cmp	byte ptr ds:[di].FormFactor,ffSmall;  Is it single-media?
+	jz	DoFloppy		; yes, use fatid...
+;
+; 96 tpi drive
+;
+	cmp	AH,0F9h
+	jnz	DoFloppy
+	mov	al,7			; seven sectors / fat
+	mov	bx,224*256+0fh		; 224 root dir entries & 0f sector max
+	mov	cx,80*15*2		; 80 tracks, 15 sectors/track, 2 sides
+	mov	dx,01*256+2		; sectors/allocation unit & head max
+popr:
+	add	SP,2			; pop off return address
+	jmp	has1_res			; return to tail of GETBP
+
+
+DoFloppy:
+	ret
+
+	PATHSTART 001,TPI96						  ;;Rev 3.30 Modification
+									  ;;End of Modification
+;
+; Certain poorly designed programs avoid DOS altogether and use INT 13 directly.
+; These programs even retry operations and, thus, will ignore the disk change
+; logic.
+;
+; We hook INT 13 and note all errors.
+;
+	assume	ds:nothing,es:nothing,ss:nothing
+
+	Public REAL13
+Real13	dd  ?
+OldInt	dd  ?
+dmy	dw  ?
+
+	PATHEND 001,TPI96						 ;;Rev 3.30 Modification
+									 ;;End of Modification
+	Public Int13
+Int13	proc	FAR
+	pop	word ptr OldInt
+	pop	word ptr OldInt+2
+	pop	DMY
+	MESSAGE FTEST13,<"*">                                             ;;Rev 3.30 Modification
+	pushf								  ;;End of Modification
+	call	REAL13			; simulate another INT 13
+	jc	Err13			; did an error occur?
+	jmp	OldInt			; no, return and pop off flags
+Err13:
+	MESSAGE FTEST13,<"INT 13 ERROR ">                                 ;;Rev 3.30 Modification
+	MNUM	FTEST13,AX						  
+	MESSAGE FTEST13,<CR,LF> 					  
+	pushf				; save state
+	cmp	AH,06h			; is error a 'change' error?
+	jz	GOTERR			; yes, jump down
+B:	popf				; no, some other error, ignore it ;;End of Modification
+	jmp	OldInt			; return and pop off flags
+
+
+GotErr: or	DL,DL			; is this for the hard disk?
+	js	B			; yes, ignore
+	mov	word ptr cs:[FlagBits],fChanged
+	call	Set_Changed_DL
+	jmp	B
+INT13	endp
+
+
+
+;
+; Set_Changed_DL - Sets flag bits according to bits set in [FlagBits].
+;		   Essentially used to indicate Changeline, or Format.
+;
+;   Inputs:	DL contains physical drive number
+;		[FlagBits] contains bits to set in the flag field in the BDSs
+;   Outputs:	None
+;   Registers modified: Flags
+;
+
+Set_Changed_DL:
+	PUBLIC SET_CHANGED_DL						  ;;Rev 3.30 Modification
+	Message ftest96,<"Set Changed",cr,lf>				  ;;End of Modification
+	push	BX
+	push	DX
+	mov	BL,DL
+ALL_SET:
+	mov	dx,cs:[FlagBits]	; get bits to set in flag field
+	xor	BH,BH
+;
+; In the virtual drive system we *must* flag the other drives as being changed
+;
+; assume first BDS is in this segment
+	push	ax
+	push	ds		    ; save current BDS
+	push	di
+	lds	di,dword ptr cs:[Start_BDS]
+Scan_BDS:
+	cmp	di,-1
+	jz	SkipSet
+	cmp	byte ptr [di].DriveNum,bl
+	jnz	Get_Next_BDS
+;
+; Someone may complain, but this *always* must be done when a disk change is
+; noted.  There are *no* other compromising circumstances.
+;
+SetChanged:
+	or	word ptr ds:[di].flags,dx	; signal change on other drive
+Get_Next_BDS:
+	mov	ax,word ptr [di].link+2   ; go to next BDS
+	mov	di,word ptr [di].link
+	mov	ds,ax
+	jmp	short Scan_BDS
+SkipSet:
+	pop	di		    ; restore current BDS
+	pop	ds
+	pop	ax
+	pop	DX
+	pop	BX
+	ret
+
+
+
+;
+; CheckROMChange - see if external program has diddled ROM change line.
+;
+;   Inputs:	DS:DI points to current BDS.
+;   Outputs:	Zero set - no change
+;		Zero reset - change
+;   Registers modified: none
+
+CheckROMChange:
+	MESSAGE FTEST13,<"CHECKROM ">                                     ;;Rev 3.30 Modification
+	MNUM	FTEST13 						  
+	MESSAGE FTEST13,<CR,LF> 					  ;;End of Modification
+	test	word ptr [di].flags,fChanged
+	ret
+
+
+
+
+;
+; ResetChanged - restore value of change line
+;
+;   Inputs:	DS:DI points to current BDS
+;   Outputs:	none
+;   Registers modified: none
+
+ResetChanged:
+	MESSAGE FTEST13,<"RESETCHANGED ">                                 ;;Rev 3.30 Modification
+	MNUM	FTEST13 	
+	MESSAGE FTEST13,<CR,LF> 					  ;;End of Modification
+	and	word ptr ds:[di].flags,NOT fChanged
+	ret
+
+
+
+;
+; HasChange - see if drive can supply change line
+;
+;   Inputs:	DS:DI points to current BDS
+;   Outputs:	Zero set - no change line available
+;		Zero reset - change line available
+;   Registers modified: none
+
+	PUBLIC	HASCHANGE						  ;;Rev 3.30 Modification
+HasChange:
+	MESSAGE FTEST13,<"HASCHANGE ">                                    
+	MNUM	FTEST13 						  
+	MESSAGE FTEST13,<CR,LF> 					  ;;End of Modification
+	test	word ptr [di].flags,fChangeline
+	ret
+
+	ASSUME	DS:CODE
+
+	include msvolid.inc
+
+	Public End96tpi
+End96tpi Label Byte

SRC/BIOS/MSAUX.ASM

@@ -0,0 +1,281 @@
+	TITLE MSAUX - DOS 3.3
+;----------------------------------------------------------------
+;								:
+;	     A U X - AUXILARY DEVICE DRIVER			:
+;								:
+;								:
+;   This file contains the Auxilary Device Driver.  The 	:
+; auxilary driver handles calls to and from the RS-232 port.	:
+; Three devices uses this code: AUX, COM1, and COM2.  AUX and	:
+; COM1 talk to the zero RS-232 card and COM2 talks to the	:
+; 'one' RS-232 card.  The beginning of the interrupt entry      :
+; point for these devices sets the variable AUXNUM in the	:
+; msbio.asm module.  If the value is 0 the routines in this	:
+; file will talk to the the 'zero' card.  If the value in       :
+; AUXNUM is 1 the routines will talk to the 'one' card.         :
+; The procedure GETDX is called to put the value 0 or 1 in	:
+; the DX register depending on the value in AUXBUF.		:
+;								:
+;   The routines in this files are:				:
+;								:
+;	routine 		function			:
+;	------- 		--------			:
+;	AUX$READ		Read characters from the	:
+;				  specified device.		:
+;	AUX$RDND		Non-desrucrtive read with	:
+;				  no waiting.			:
+;	AUX$FLSH		Flush specified device input	:
+;				  buffer.			:
+;	AUX$WRIT		Write characters to the 	:
+;				  specified device.		:
+;	AUX$WRST		Get status of specified 	:
+;				  device			:
+;								:
+;  These routines are not called directly.  Call are made via	:
+; the strategy and interrupt entry point (see Device Header).	:
+;								:
+;  Data structure:						:
+;    The Aux Device has a two byte buffer called AUXBUF.  The	:
+;  first byte is for the zero card, the second byte is for the	:
+;  one card.  A zero value in the byte indicates the buffer is	:
+;  empty.  The routines use GETBX to get the address of the	:
+;  buffer.							:
+;								:
+;----------------------------------------------------------------
+
+;;Ver 3.30 modification ---------------------------
+	test=0
+	INCLUDE MSGROUP.INC	;DEFINE CODE SEGMENT
+	INCLUDE JUMPMAC.INC
+	INCLUDE MSMACRO.INC
+
+	EXTRN ERR$CNT:NEAR	;MSBIO1
+	EXTRN GETDX:NEAR	;MSBIO1
+	EXTRN RDEXIT:NEAR	;MSCON
+	EXTRN EXIT:NEAR 	;MSBIO1
+	EXTRN BUS$EXIT:NEAR	;MSBIO1
+				;DATA
+	EXTRN AUXBUF:BYTE	;MSDATA
+
+;		VALUES IN AH, REQUESTING FUNCTION OF INT 14H IN ROM BIOS
+AUXFUNC_SEND	 EQU	1	;TRANSMIT
+AUXFUNC_RECEIVE  EQU	2	;READ
+AUXFUNC_STATUS	 EQU	3	;REQUEST STATUS
+
+;		ERROR FLAGS, REPORTED BY INT 14H
+
+;	 THESE FLAGS REPORTED IN AH:
+FLAG_DATA_READY  EQU	01H	;DATA READY
+FLAG_OVERRUN	 EQU	02H	;OVERRUN ERROR
+FLAG_PARITY	 EQU	04H	;PARITY ERROR
+FLAG_FRAME	 EQU	08H	;FRAMING ERROR
+FLAG_BREAK	 EQU	10H	;BREAK DETECT
+FLAG_TRANHOL_EMP EQU	20H	;TRANSMIT HOLDING REGISTER EMPTY
+FLAG_TRANSHF_EMP EQU	40H	;TRANSMIT SHIFT REGISTER EMPTY
+FLAG_TIMEOUT	 EQU	80H	;TIMEOUT
+
+;	THESE FLAGS REPORTED IN AL:
+FLAG_DELTA_CTS	 EQU	01H	;DELTA CLEAR TO SEND
+FLAG_DELTA_DSR	 EQU	02H	;DELTA DATA SET READY
+FLAG_TRAIL_RING  EQU	04H	;TRAILING EDGE RING INDICATOR
+FLAG_DELTA_SIG	 EQU	08H	;DELTA RECEIVE LINE SIGNAL DETECT
+FLAG_CTS	 EQU	10H	;CLEAR TO SEND
+FLAG_DSR	 EQU	20H	;DATA SET READY
+FLAG_RING	 EQU	40H	;RING INDICATOR
+FLAG_REC_SIG	 EQU	80H	;RECEIVE LINE SIGNAL DETECT
+;;End of modification ------------------
+
+
+;----------------------------------------------------------------
+;								  :
+;	Read zero or more characters from Auxilary Device	  :
+;								  :
+;	input:es:[di] points to area to receive aux data	  :
+;	      cx has number of bytes to be read 		  :
+;	      "auxnum" first byte has number of aux device (rel 0):
+;								  :
+;----------------------------------------------------------------
+	PUBLIC AUX$READ
+AUX$READ PROC NEAR
+	ASSUME	DS:CODE 	; SET BY AUX DEVICE DRIVER ENTRY ROUTINE
+	jcxz	EXVEC2		; if no characters, get out
+	call	GETBX		; put address of AUXBUF in BX
+	xor	AX,AX		; clear AX register
+	xchg	AL,[BX] 	; Get character , if any, from
+				;   buffer and clear buffer
+	or	AL,AL		; if AL is nonzero there was a
+				;   character in the buffer
+	jnz	AUX2		; if so skip AUXIN call
+AUX1:				;
+	call	AUXIN		; get character from port
+AUX2:				;
+	stosb			; store character
+	loop	AUX1		; if more character, go around again
+EXVEC2: 			;
+	Jump	EXIT		; all done, successful exit
+AUX$READ ENDP
+
+;
+; AUXIN: make a call on ROM BIOS to read character from
+;	 the auxilary device, then do some error checking.
+;	 If an error occurs then AUXIN jumps to ERR$CNT and
+;	 does NOT return to where it was called from.
+;
+
+AUXIN	PROC	NEAR
+
+	mov	ah,AUXFUNC_RECEIVE
+	call	AUXOP
+	 			;check for Frame, Parity, or Overrun errors
+	 			;WARNING: these error bits are unpredictable 
+	 			;         if timeout (bit 7) is set
+	test	ah,FLAG_FRAME or FLAG_PARITY or FLAG_OVERRUN
+	jz	AROK		;No error if all bits are clear
+
+	 ;Error getting character
+	add	sp,+2		;Remove rtn address (near call)
+	xor	al,al
+	or	al,FLAG_REC_SIG or FLAG_DSR or FLAG_CTS
+
+	JUMP	ERR$CNT
+AROK:
+	RET			;CHAR JUST READ IS IN AL, STATUS IS IN AH
+AUXIN	ENDP
+
+;----------------------------------------------------------------
+;								:
+;	Aux non-destructive read with no waiting		:
+;								:
+;	input: es:[di] points to area to receive aux data	:
+;								:
+;----------------------------------------------------------------
+;
+	PUBLIC	AUX$RDND
+AUX$RDND PROC	NEAR
+	ASSUME	DS:CODE 	; SET BY AUX DEVICE DRIVER ENTRY ROUTINE
+	call	GETBX		; have BX point to AUXBUF
+	mov	AL,[BX] 	; copy contents of buffer to AL
+	or	AL,AL		; if AL is non-zero (char in buffer)
+	jnz	AUXRDX		;   then return character
+	call	AUXSTAT 	;   if not, get status of AUX device
+	TEST	AH,FLAG_DATA_READY ;TEST DATA READY
+	jz	AUXBUS		;   then device is busy (not ready)
+
+	TEST	AL,FLAG_DSR	;TEST DATA SET READY
+	jz	AUXBUS		;   then device is busy (not ready)
+	call	AUXIN		;   else aux is ready, get character
+	call	GETBX		; have bx point to AUXBUF
+	mov	[BX],AL 	; save character in buffer
+AUXRDX: 			;
+	Jump	RDEXIT		; return character
+
+AUXBUS: 			;
+	Jump	BUS$EXIT	; jump to device busy exit
+AUX$RDND ENDP
+
+;----------------------------------------------------------------
+;								:
+;		Aux Output Status				:
+;								:
+;----------------------------------------------------------------
+	PUBLIC AUX$WRST
+AUX$WRST PROC	NEAR
+	ASSUME	DS:CODE 	; SET BY AUX DEVICE DRIVER ENTRY ROUTINE
+	call	AUXSTAT 	; get status of AUX in AX
+				; now test to see if device is busy
+				; if this bit is not set,
+;;Ver 3.30 modification -----------------------
+	TEST	AL,FLAG_DSR	;TEST DATA SET READY
+	jz	AUXBUS		;   then device is busy (not ready)
+	TEST	AH,FLAG_TRANHOL_EMP ;TEST TRANSMIT HOLD REG EMPTY
+;;End of modification -------------------------
+	jz	AUXBUS		;   then device is busy (not ready)
+	Jump	Exit
+
+AUX$WRST ENDP
+
+;
+; AUXSTAT makes a call on the ROM-BIOS to determine the status
+;	  of the auxilary device
+;	  Outputs:
+;		AX is filled with status of port.
+;		DX is changes to specify which card - either 0, 1 (, 2, 3) ;ba
+;		NO other registers are modified
+;
+
+AUXSTAT	proc near
+	mov	ah,AUXFUNC_STATUS
+	call	AUXOP
+	ret
+AUXSTAT endp
+
+AUXOP	PROC	NEAR
+				;AH=FUNCTION CODE
+				;0=INIT, 1=SEND, 2=RECEIVE, 3=STATUS
+	call	GETDX		; have DX point to proper card
+	int	14h		; call rom-bios for status
+	ret
+AUXOP	ENDP
+
+;----------------------------------------------------------------
+;								:
+;  Flush AUX Input buffer - set contents of AUXBUF to zero	:
+;								:
+;----------------------------------------------------------------
+	PUBLIC AUX$FLSH
+AUX$FLSH PROC	NEAR
+	ASSUME	DS:CODE 	; SET BY AUX DEVICE DRIVER ENTRY ROUTINE
+	call	GETBX		; get BX to point to AUXBUF
+	mov	BYTE PTR [BX],0 ; zero out buffer
+	Jump	Exit		; all done, successful return
+AUX$FLSH ENDP
+
+
+
+;----------------------------------------------------------------
+;								:
+;		Write to Auxilary Device			:
+;								:
+;----------------------------------------------------------------
+	PUBLIC	AUX$WRIT
+AUX$WRIT PROC	NEAR
+	ASSUME	DS:CODE 	; SET BY AUX DEVICE DRIVER ENTRY ROUTINE
+	jcxz	EXVEC2		; if CX is zero, no characters
+				;   to be written, jump to exit
+AUX$LOOP:
+	mov	AL,ES:[DI]	; get character to be written
+	inc	DI		; move DI pointer to next character
+;;Ver 3.30 modification ---------------------------
+	MOV	AH,AUXFUNC_SEND ;VALUE=1, INDICATES A WRITE
+	CALL	AUXOP		;SEND CHARACTER OVER AUX PORT
+
+	TEST	AH,FLAG_TIMEOUT ;CHECK FOR ERROR
+;;End of modification ---------------------------
+	jz	AWOK		;   then no error
+	mov	AL,10		;   else indicate write fault
+	Jump	ERR$CNT 	; call error routines
+
+				; if CX is non-zero, still more
+AWOK:
+	loop	AUX$LOOP	; more characrter to print
+	Jump	Exit		; all done, successful return
+AUX$WRIT ENDP
+
+
+;
+;  GETBX puts the address of AUXBUF (the Auxilary Device buffer)
+;	 in BX.  After calling GETBX, a routine can get to AUXBUF
+;	 with [BX].
+;
+;  NOTE: The getdx routine is in msbio1 and looks like:
+;	mov	dx,word ptr cs:[auxnum]
+;
+GETBX	PROC	NEAR
+	call	GETDX
+	mov	BX,DX
+	add	BX,OFFSET AUXBUF
+	ret
+GETBX	ENDP
+
+CODE	ENDS
+	END

SRC/BIOS/MSBDS.INC

@@ -0,0 +1,118 @@
+;
+;  BDS is the Bios Data Structure.
+;
+;  There is one BDS for each logical drive in the system.  All the BDS's
+;  are linked together in a list with the pointer to the first BDS being
+;  found in Start_BDS.	The BDS hold various values important to the disk
+;  drive.  For example there is a field for last time accesses.  As actions
+;  take place in the system the BDS are update to reflect the actions.
+;  For example is there is a read to a disk the last access field for the
+;  BDS for that drive is update to the current time.
+;
+; Values for various flags in BDS.Flags.
+;
+
+fNon_Removable	    equ     01H 	;For non-removable media
+fChangeline	    equ     02H 	;If changeline supported on drive
+RETURN_FAKE_BPB     equ     04H 	; When set, don't do a build BPB
+					; just return the fake one
+GOOD_TRACKLAYOUT    equ     08H 	; The track layout has no funny sectors
+fI_Am_Mult	    equ     10H 	;If more than one logical for this physical
+fI_Own_Physical     equ     20H 	;Signify logical owner of this physical
+fChanged	    equ     40H 	;Indicates media changed
+SET_DASD_true	    equ     80H 	; Set DASD before next format
+fChanged_by_format  equ    100h
+
+;
+; Various form factors to describe media
+;
+
+ff48tpi 	    equ     0
+ff96tpi 	    equ     1
+ffSmall 	    equ     2
+ffHardFile	    equ     5
+ffOther 	    equ     7
+
+BDS_Type struc
+Link		DD		?	; Link to next BDS
+DriveNum	DB		?	; Physical drive number
+DriveLet	DB		?	; DOS drive number
+BytePerSec	DW		?	; number of bytes/sec
+SecPerClus	DB		?	; sec per allocation unit
+RESSEC		DW		?	; number of reserved sectors
+cFAT		DB		?	; number of fats
+cDir		DW		?	; number of directory entries
+DRVLIM		DW		?	; number of sectors on medium
+mediad		DB		?	; media descriptor byte
+cSecFat 	DW		?	; number of sectors/fat
+SECLIM		DW		?	; sectors per track
+HDLIM		DW		?	; max number of heads
+HIDSEC		DW		?	; number of hidden sectors
+FatSiz		DB		?	; flags...
+Opcnt		DW		?	; Open ref. count
+Volid		DB		12 dup (?)	; volume ID of medium
+FormFactor	DB		?	; form factor index
+Flags		DW		?	; various flags
+cCyln		DW		?	; max number of cylinders
+RBytePerSec	DW		?	; Recommended BPB
+RSecPerClus	DB		?
+RRESSEC 	DW		?
+RcFAT		DB		?
+RcDir		DW		?
+RDRVLIM 	DW		?
+Rmediad 	DB		?
+RcSecFat	DW		?
+RSECLIM 	DW		?
+RHDLIM		DW		?
+RHIDSEC 	DW		?
+RHHIDSEC	DW		?
+RLOGSEC 	DD		?
+Reserve 	DB		6 dup (?)	; Reserved for future
+					; changed to word -- kcd9:85
+Track		DB		?	; last track accessed on drive
+Tim_Lo		DW		?	; Time of last access. Keep
+Tim_Hi		DW		?	; these contiguous.
+BDS_Type ends
+
+BPBSize     =	Track - RBytePerSec ; size in bytes of RecBPB area in the BDS
+
+
+;;Rev 3.30 Modification
+;*********************************************************************
+;	BDS structure for mini disk
+;*********************************************************************	  
+									  
+BDSM_type	struc							  
+mlink		DW	-1			;Link to next structure   
+		DW	?						  
+mdriveNum	DB	80			;Int 13 Drive Number	  
+mdriveLet	DB	3			;Logical Drive Number	  
+mBytePerSec	DW	512						  
+mSecPerClus	DB	1			;Sectors/allocation unit  
+mRESSEC 	DW	1			;Reserved sectors for DOS 
+mcFAT		DB	2			;No. of allocation tables 
+mcDIR		DW	16			;Number of directory entries
+mDRVLIM 	DW	0			;Number of sectors (at 512 bytes each)
+mMediad 	DB	11111000B		;Media descriptor	  
+mcSecFat	DW	1			;Number of FAT sectors	  
+mSECLIM 	DW	0			;Sector limit		  
+mHDLIM		DW	0			;Head limit		  
+mHIDSEC 	DW	0			;Hidden sector count	  
+mFatSiz 	DB	0			;TRUE => bigfat 	  
+mOPCNT		DW	0			;Open Ref. Count	  
+mVOLID		DB	"NO NAME    "           ;Volume ID for this disk  
+		DB	0			;ASCIZII for "NO NAME    "
+mFormFactor	DB	3			;Form Factor		  
+mFLAGS		DW	0020H			;Various Flags		  
+mcCyln		dw	40			;max number of cylinders  
+mRecBPB 	db	31 dup (0)		;Recommended BPB for drive
+mTrack		db	-1						  
+IsMini		dw	1			;Overlapping TIM_LOH	  
+Hidden_Trks	dw	0			;Overlapping TIM_HIH	  
+									  
+;TIM_LOH DW	 -1			 ;Keep these two contiguous (?)   
+;TIM_HIH DW	 -1							  
+BDSM_type	ENDS							  
+;******************************************************************************
+Max_mini_dsk_num = 23	      ; Max # of mini disk bios can support
+;;End of Modification

SRC/BIOS/MSBIO.LNK

@@ -0,0 +1,5 @@
+msbio1+mscon+msaux+mslpt+msclock+msdisk+
+msbio2+mshard+msinit+sysinit1+sysconf+sysinit2+sysimes,
+msbio,
+msbio/m;
+

SRC/BIOS/MSBIO1.ASM

@@ -0,0 +1,693 @@
+	TITLE	MSBIO	MS-DOS 3.30
+
+;-------------------------------------------------------------------------------
+;									       :
+;			    Microsoft Bio				       :
+;									       :
+;  The file msbio.asm is the main file in the Mircosoft bio.  This file        :
+; includes the other main files in the bio.  Most of the routines are	       :
+; in these include files.  The main files included are: 		       :
+;									       :
+;	File		Contains					       :
+;									       :
+;	msdisk.inc	Disk device driver routines			       :
+;	ms96tpi.inc	Routines for 96tpi drives			       :
+;	msaux.inc	Device driver for the rs-232 serial ports	       :
+;	msclock.inc	Device driver for "clock$" device                      :
+;	mscon.inc	Device driver for "con"                                :
+;	mslpt.inc	Device driver for the printers			       :
+;									       :
+;  Each of these files contain a header section documenting the code	       :
+;  in that file.							       :
+;    Msbio also includes several files for equ's, structure definition,        :
+;  macro definitions, etc.  These are:					       :
+;									       :
+;	msbiomes.inc	 msmacro.inc	devsym.inc			       :
+;		dskprm.inc	   error.inc				       :
+;									       :
+;  Each of these file contains explanitory notes.			       :
+;									       :
+;    The actual code in msbio can be broken down into several piece:	       :
+;									       :
+;	macro definitions	Several marco are defined in msbio.  They      :
+;				are a few odds and end that did not fit        :
+;				anywhere else.				       :
+;									       :
+;	Command Jump Table	List of entry points in the device drivers.    :
+;				See notation below for full explination.       :
+;									       :
+;	Interrupt and Strategy						       :
+;	  Entry points		Calls on the device driver first come to here. :
+;				There is common code with pushes registers and :
+;				the like before jumping to routines in the     :
+;				driver files.  The common exit points are also :
+;				in this file.				       :
+;									       :
+;	Miscellaneous Code	There are several routines and data structure  :
+;				declarations.  See below for details.	       :
+;									       :
+;-------------------------------------------------------------------------------
+
+
+
+;
+; If the variable TEST is non-zero then code for debugging is included.
+; The extra code will make the binary file nuch larger.
+; The symbol is also defined in msequ.inc.  Both must be changed to
+; turn debugging on or off.
+;
+; The level of the debugging is controled by the variable fTestBits in
+; this file.  See the comment preceeding the variable for more information.
+; The actual routines which print the messages are in msmacro.inc
+; See the header comment in this file for more information.
+;
+;***For testing purposes, set the TEST flag to 1. Otherwise reset it.
+
+TEST=0
+
+PATHGEN =	1
+
+.SALL
+;
+; This is a DOSMAC macro which is used in DEVSYM which is included later.
+;
+
+BREAK	MACRO	subtitle
+	SUBTTL	subtitle
+	PAGE
+	ENDM
+
+;
+; Some old versions of the 80286 have a bug in the chip.  The popf
+; instruction will enable interrupts.  Therefore in a section of code with
+; interrupts disabled and you need a popf instruction use the 'popff'
+; macro instead.
+;
+
+POPFF	macro
+	jmp	$+3
+	iret
+	push	cs
+	call	$-2
+	endm
+
+;;Rev 3.30 modification -----------------------------
+	INCLUDE MSGROUP.INC	;DEFINE CODE SEGMENT
+
+SYSINITSEG SEGMENT PUBLIC 'SYSTEM_INIT'
+SYSINITSEG ENDS
+
+
+	INCLUDE JUMPMAC.INC
+PATHSTART MACRO INDEX,ABBR
+	IFDEF	PATHGEN
+	    PUBLIC  ABBR&INDEX&S,ABBR&INDEX&E
+	    ABBR&INDEX&S LABEL	 BYTE
+	ENDIF
+	ENDM
+
+PATHEND MACRO	INDEX,ABBR
+	IFDEF	PATHGEN
+	    ABBR&INDEX&E LABEL	 BYTE
+	ENDIF
+	ENDM
+
+	INCLUDE PUSHPOP.INC
+	INCLUDE DEVSYM.INC		;MJB001
+;; End of Modification
+
+;
+; Revision History
+;
+;   REV 2.1	5/1/83 ARR added timer int handler and changed order of AUX
+;		    PRN init for HAL0
+;
+;   REV 2.15	7/13/83 ARR Because of IBM design issues, and that BASCOM
+;		    is ill behaved with respect to the 1CH timer interrupt,
+;		    the timer handler has to be backed out! The intended
+;		    code is commented out and has an ARR 2.15 annotation.
+;		    This means the BIOS will go back to the multiple roll
+;		    over bug.
+;
+;   REV 2.20	8/5/83 ARR IBM makes hardware change.  Now wants to use half
+;		    height drives for HAL0, and back fit for PC/PC XT.	Problem
+;		    with head settle time.  Previous drives got by on a 0
+;		    settle time, 1/2 hight drives need 15 head settle when
+;		    doing WRITEs (0 ok on READ) if the head is being stepped.
+;		    This requires a last track value to be kept so that BIOS
+;		    knows when head is being moved.  To help out
+;		    programs that issue INT 13H directly, the head settle will
+;		    normally be set to 15.  It will be changed to 0 on READs,
+;		    or on WRITEs which do not require head step.
+;
+;   REV 2.21	8/11/83 MZ IBM wants write with verify to use head settle 0.
+;		    Use same trick as above.
+;
+;   REV 2.25	6/20/83 mjb001 added support for 96tpi and salmon
+;
+;   REV 2.30	6/27/83 mjb002 added real-time clock
+;
+;   REV 2.40	7/8/83 mjb003 added volume-id checking and int 2f macro
+;		    definitions push* and pop*
+;
+;   REV 2.41	7/12/83 ARR more 2.X enhancements.  Open/Close media change
+;
+;   REV 2.42	11/3/83 ARR more 2.X enhancements.  Disk OPEN/CLOSE, FORMAT
+;		    code and other misc hooked out to shrink BIOS.  Code for
+;		    Disk OPEN/CLOSE, FORMAT included only with 96tpi disks.
+;
+;   Rev   2.43	12/6/83 MZ Examine boot sectors on hard disks for 16-bit fat
+;		    check.  Examine large fat bit in BPB for walk of media for
+;		    DOS
+;
+;   Rev   2.44	12/9/83 ARR Change to error reporting on INT 17H
+;
+;   Rev   2.45	12/22/83 MZ Make head settle change only when disk parm is 0.
+;
+;   Rev   3.21	3/20/87 SP Changed OUTCHR routine to always output to page 0.
+
+;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+;
+;	IBM ADDRESSES FOR I/O
+;
+;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+
+include dskprm.inc
+
+	SYSIZE	= 100H			; number of paragraphs in sysinit module
+	LF	= 10			; line feed
+	CR	= 13			; carriage return
+	BACKSP	= 8			; backspace
+	BRKADR	= 1BH * 4		; 006C	1Bh break vector address
+	TIMADR	= 1CH * 4		; 0070	1Ch timer interrupt
+	DSKADR	= 1EH * 4		; address of ptr to disk parameters
+	SEC9	= 522H			; address of disk parameters
+	HEADSETTLE	= SEC9+9	; address of head settle time
+	NORMSETTLE	= 15		; Normal head settle
+	SPEEDSETTLE	= 0		; Speed up settle time
+	INITSPOT	= 534H		; IBM wants 4 zeros here
+	AKPORT	= 20H
+	EOI	= 20H
+	
+;;Rev 3.30 modification -----------------------------
+	ASSUME	CS:CODE,DS:NOTHING,ES:NOTHING
+	
+	EXTRN	MEDIA$CHK:NEAR
+	EXTRN	GET$BPB:NEAR
+	EXTRN	DSK$INIT:NEAR
+	EXTRN	DSK$READ:NEAR
+	EXTRN	DSK$WRIT:NEAR
+	EXTRN	DSK$WRITV:NEAR
+	EXTRN	DSK$OPEN:NEAR
+	EXTRN	DSK$CLOSE:NEAR
+	EXTRN	DSK$REM:NEAR
+	EXTRN	GENERIC$IOCTL:NEAR
+	EXTRN	IOCTL$GETOWN:NEAR
+	EXTRN	IOCTL$SETOWN:NEAR
+	EXTRN	CON$READ:NEAR
+	EXTRN	CON$RDND:NEAR
+	EXTRN	CON$FLSH:NEAR
+	EXTRN	CON$WRIT:NEAR
+;	EXTRN	CON$GENIOCTL:NEAR
+	EXTRN	AUX$READ:NEAR
+	EXTRN	AUX$WRIT:NEAR
+	EXTRN	AUX$FLSH:NEAR
+	EXTRN	AUX$RDND:NEAR
+	EXTRN	AUX$WRST:NEAR
+	EXTRN	TIM$READ:NEAR
+	EXTRN	TIM$WRIT:NEAR
+	EXTRN	PRN$WRIT:NEAR
+	EXTRN	PRN$STAT:NEAR
+	EXTRN	PRN$TILBUSY:NEAR
+	EXTRN	PRN$GENIOCTL:NEAR
+	EXTRN	WRMSG:NEAR
+;DATA AREAS
+	INCLUDE MSDATA.INC
+;;End of modification -----------------------------
+
+;
+; The following variables and two routines (MSGOUT and MSGNUM) are used
+; with the debug routines to print numbers and messages on the screen.
+;
+; The variable fTestBits controls the level of debugging in the system.
+; See the comments and "equ's" in msmacro.inc for an explination of
+; how to control the level of debugging.  In a nutshell, setting
+; fTestBits to fTestALL prints all the debugging messages.  Setting
+; it to fTestDisk prints all disk related messages, etc.
+;
+
+if test
+Public MSGNUM
+MSGNUM:
+	pushf
+	test	fTestBits,AX
+	jz	MRet
+	push	SI
+	push	BX
+	push	CX
+	push	ES
+	push	DI
+	mov	DI,OFFSET NUMBUF
+	push	CS
+	pop	ES
+	mov	CX,4
+NUMLOOP:
+	push	CX
+	mov	CL,4
+	rol	BX,CL
+	pop	CX
+	push	BX
+	and	BX,0Fh
+	mov	AL,Digits[BX]
+	stosb
+	pop	BX
+	loop	NumLoop
+	pop	DI
+	pop	ES
+	pop	CX
+	pop	BX
+	mov	SI,OFFSET NUMBUF
+	call	MSGOUT
+	pop	SI
+	popf
+	ret
+
+Public MSGOUT
+MSGOUT:
+	pushf
+	test	fTestBits,ax
+	jz	MRet
+	push	DS
+	push	AX
+	push	BX
+	push	CS
+	pop	DS
+	call	WRMSG
+	pop	BX
+	pop	AX
+	pop	DS
+MRet:
+	popf
+	ret
+;;Rev 3.30 modification -----------------------------
+	    PUBLIC DUMPBYTES
+;Dumpbytes will dump the bytes in memory in hex.  Space will be put in
+;between the bytes and CR, LF will be put at the end. - J.K.
+;Input: DS:SI -> buffer to dump in Hex.
+;	CX -> # of bytes (Length of the buffer)
+;
+DUMPBYTES proc near
+	pushf
+	push	ax
+dumploops:
+	lodsb
+	mov	ah, al
+	shr	ah, 1
+	shr	ah, 1
+	shr	ah, 1
+	shr	ah, 1
+	call	hex_to_ascii
+	push	ax
+	mov	al, ah
+	call	outchar
+	pop	ax
+	call	outchar
+	mov	al, ' '
+	call	outchar
+	loop	dumploops
+
+	mov	al, 0dh
+	call	outchar
+	mov	al, 0ah
+	call	outchar
+
+	pop	ax
+	popf
+	ret
+DUMPBYTES	endp
+
+	PUBLIC	Hex_to_ascii
+Hex_to_ascii	proc	near
+	and	ax, 0f0fh
+	add	ah, 30h
+	cmp	ah, 3ah
+	jb	hta_$1
+	add	ah, 7
+hta_$1:
+	add	al, 30h
+	cmp	al, 3ah
+	jb	hta_$2
+	add	al, 7
+hta_$2:
+	ret
+Hex_to_ascii	endp
+
+	PUBLIC	outchar
+Outchar proc	near
+	PUSH	AX
+	PUSH	SI
+	PUSH	DI
+	PUSH	BP
+	PUSH	BX
+	MOV	AH, 0Eh 		;SET COMMAND TO WRITE A CHAR
+	MOV	BL, 7			;SET FOREGROUND COLOR
+	mov	bh,0			;
+	INT	10h			;CALL ROM-BIOS
+	POP	BX
+	POP	BP
+	POP	DI
+	POP	SI
+	POP	AX
+	RET
+Outchar endp
+
+	ENDIF
+;;End of modification -----------------------------
+
+;
+; end of routines for debugging
+;
+	INCLUDE MSMACRO.INC
+
+
+
+;
+; The next nine equ's describe the offset into the request header for
+; different information.  For example STATUS is in byte 3 of the request
+; header (starting count at zero).
+;
+
+CMDLEN	=	0			; length of this command
+UNIT	=	1			; sub unit specifier
+CMD	=	2			; command code
+STATUS	=	3			; status
+MEDIA	=	13			; media descriptor
+TRANS	=	14			; transfer address
+COUNT	=	18			; count of blocks or characters
+START	=	20			; first block to transfer
+EXTRA	=	22			; Usually pointer to Vol Id for error 15
+
+;
+; Strategy is the strategy entry point for all default bio device drivers.
+; All that is done is to save the pointer to the request header in the
+; variable PtrSav.
+;
+
+PUBLIC	STRATEGY
+STRATEGY PROC	FAR
+	mov	word ptr CS:[PTRSAV],BX
+	mov	word ptr CS:[PTRSAV+2],ES
+	ret
+
+STRATEGY ENDP
+
+
+;------------------------------------------------------------------------------
+;
+;			Device entry point
+;
+; The following ten pieces of code are the interrupt entry points for the
+; default device drivers.  These small pieces of code have two jobs.
+;
+;	1) Make SI point to the beginning of the proper command jump  table.
+;	   SI must first be pushed to preserve original contents.
+;	2) If the call is an AUX or a printer save the number of the
+;	   request in AL.  AL is moved to AUXNUM below.
+;
+
+;
+; Con device:
+;
+
+;;Rev 3.30 modification -----------------------------
+	PUBLIC CON$IN
+CON$IN	PROC	FAR
+	PUSH	SI
+	MOV	SI,OFFSET CONTBL
+	JMP	SHORT ENTRY
+CON$IN	ENDP
+
+	PUBLIC	AUX0$IN
+AUX0$IN PROC	FAR
+	PUSH	SI
+	PUSH	AX
+	XOR	AL,AL
+	JMP	SHORT AUXENT
+AUX0$IN ENDP
+
+	PUBLIC AUX1$IN
+AUX1$IN PROC	FAR
+	PUSH	SI
+	PUSH	AX
+	MOV	AL,1
+	JMP	short AUXENT
+AUX1$IN ENDP
+
+	PUBLIC  AUX2$IN
+AUX2$IN proc far
+	push	si
+	push	ax
+	mov	al,2
+	jmp	short AUXENT
+AUX2$IN endp
+
+	PUBLIC  AUX3$IN
+AUX3$IN proc far
+	push	si
+	push	ax
+	mov	al,3
+	jmp	short AUXENT
+
+AUXENT:
+	MOV	SI,OFFSET AUXTBL
+	JMP	SHORT ENTRY1
+AUX3$IN ENDP
+
+PRN0$IN PROC	FAR
+	PUBLIC	PRN0$IN
+
+	PUSH	SI
+	PUSH	AX
+	XOR	AX,AX
+	JMP	SHORT PRNENT
+PRN0$IN ENDP
+
+	PUBLIC	PRN1$IN
+PRN1$IN PROC	FAR
+	PUSH	SI
+	PUSH	AX
+	XOR	AL,AL
+	MOV	AH,1
+	JMP	SHORT PRNENT
+PRN1$IN ENDP
+
+	PUBLIC PRN2$IN
+PRN2$IN PROC	FAR
+	PUSH	SI
+	PUSH	AX
+	MOV	AL,1
+	MOV	AH,2
+	JMP	SHORT PRNENT
+PRN2$IN ENDP
+
+	PUBLIC PRN3$IN
+PRN3$IN PROC	FAR
+	PUSH	SI
+	PUSH	AX
+	MOV	AL,2
+	MOV	AH,3
+PRNENT:
+	MOV	SI,OFFSET PRNTBL
+	MOV	CS:[PRINTDEV],AH	;SAVE INDEX TO ARRAY OF RETRY CNTS
+	JMP	SHORT ENTRY1
+PRN3$IN ENDP
+
+	PUBLIC	TIM$IN
+TIM$IN	PROC	FAR
+	PUSH	SI
+	MOV	SI,OFFSET TIMTBL
+	JMP	SHORT ENTRY
+TIM$IN	ENDP
+
+	PUBLIC	DSK$IN
+DSK$IN	PROC	FAR
+	push	SI
+	mov	SI,OFFSET DSKTBL
+;;End of modification -----------------------------
+
+
+
+;
+;   This section is the prolog to all default device drivers.  All registers
+; are saved, the registers are filled with information fromthe request header,
+; and the routine from the jump table is called.  Error checking is done
+; to assure command code is valid.  Before calling the routine in the
+; jump table the register are:
+;
+;	AH = Media Descriptor
+;	AL = Unit Code
+;	BX = offset to PTRSAV (request header is therefore at DS:BX)
+;	CX = count from request header
+;	DX = start sector
+;	ES:DI = tranfer address
+;	SI = points to jump table
+;	DS = points to this segment
+;
+; Once the routine finishes its job it jumps back to one of the eight
+; pieces of code below labeled Exit Points.
+;
+
+ENTRY:
+	push	AX
+ENTRY1:
+	push	CX			; save all registers
+	push	DX
+	push	DI
+	push	BP
+	push	DS
+	push	ES
+	push	BX
+
+	mov	CS:[AUXNUM],AL		; save choice of AUX/PRN device
+
+	lds	BX,CS:[PTRSAV]		; get pointer to I/O packet
+	ASSUME	DS:NOTHING
+
+	mov	AL,byte ptr DS:[BX].UNIT    ;AL = UNIT CODE
+	mov	AH,byte ptr DS:[BX].MEDIA   ;AH = MEDIA DESCRIP
+	mov	CX,word ptr DS:[BX].COUNT   ;CX = COUNT
+	mov	DX,word ptr DS:[BX].START   ;DX = START SECTOR
+
+	xchg	DI,AX
+	mov	AL,BYTE PTR DS:[BX].CMD
+	cmp	AL,CS:[SI]		; is command code a valid number?
+	ja	CMDERR			; no, jump to handle error
+
+	cbw				; note that AL <= 15 means OK
+	shl	AX,1
+	add	SI,AX			; get SI to point to address of routine
+	xchg	AX,DI			; put proper value back into AX
+					; get ES:DI to point to transfer address
+	les	DI,DWORD PTR DS:[BX].TRANS
+	push	CS			; get DS equal to CS
+	pop	DS
+
+	ASSUME	DS:CODE
+
+	cld				; clear the direction flag
+	jmp	WORD PTR [SI+1] 	; go to the command
+
+DSK$IN	ENDP
+PAGE
+;=====================================================
+;=
+;=	SUBROUTINES SHARED BY MULTIPLE DEVICES
+;=
+;=====================================================
+
+
+
+;----------------------------------------------------------
+;
+;		Exit  Points
+;
+; All device driver call return through one of these eight
+; pieces of code.  The code set error and status conditions
+; and then restores the registers.
+;
+
+PUBLIC BUS$EXIT 			; device busy exit
+BUS$EXIT PROC	FAR
+	ASSUME	DS:NOTHING
+	mov	AH,00000011B		; set error code
+	jmp	SHORT ERR1
+
+PUBLIC CMDERR
+CMDERR:
+	mov	AL,3			; unknown command error
+
+PUBLIC ERR$CNT
+ERR$CNT:
+	lds	BX,CS:[PTRSAV]
+	ASSUME	DS:NOTHING
+	sub	WORD PTR [BX].COUNT,CX	;# of successful I/O's
+
+PUBLIC ERR$EXIT
+ERR$EXIT:
+	mov	AH,10000001B		; mark error and return
+	jmp	SHORT ERR1
+
+BUS$EXIT ENDP
+EXITP	proc	FAR
+	ASSUME	DS:CODE
+
+EXIT$ZER:
+	lds	BX,[PTRSAV]
+	ASSUME	DS:NOTHING
+	xor	AX,AX
+	mov	WORD PTR [BX].COUNT,AX	; indicate no character read
+
+Public EXIT
+EXIT:
+	ASSUME	DS:NOTHING
+	mov	AH,00000001B
+ERR1:
+	ASSUME	DS:NOTHING
+	lds	BX,CS:[PTRSAV]
+	mov	WORD PTR [BX].STATUS,AX ; mark operation complete
+
+	pop	BX		; restore register and return
+	pop	ES
+	pop	DS
+	pop	BP
+	pop	DI
+	pop	DX
+	pop	CX
+	pop	AX
+	pop	SI
+	ret
+EXITP	endp
+
+
+;-------------------------------------------------------------
+;
+; Chrout - write out character in AL using current attribute
+;
+;   called via int 29h
+;
+	PUBLIC	CHROUT
+CHROUT	=	29H
+
+	Public	OUTCHR
+OUTCHR	PROC	FAR
+	push	AX			; preserve affect registers
+	push	SI
+	push	DI
+	push	BP
+	push	bx			;
+	mov	AH, 0Eh 		; set command to write a character
+	mov	bh,0			;
+	mov	BL, 7			; set foreground color
+	int	10h			; call rom-bios
+	pop	bx			;
+	pop	BP			; restore registers
+	pop	DI
+	pop	SI
+	pop	AX
+	iret
+OUTCHR	ENDP
+
+
+;----------------------------------------------
+;
+; Fill DX register with value in AUXNUM
+;
+
+	PUBLIC GETDX
+GETDX	PROC	NEAR
+	mov	DX,WORD PTR CS:[AUXNUM]
+	ret
+GETDX	ENDP
+	page
+CODE	ENDS
+	END

SRC/BIOS/MSBIO2.ASM

@@ -0,0 +1,650 @@
+	TITLE MSBIO2 - DOS 3.3
+
+;-------------------------------------------------------------------------------
+;									       :
+;			    Microsoft Bio				       :
+;									       :
+;  The file msbio.asm is the main file in the Mircosoft bio.  This file        :
+; includes the other main files in the bio.  Most of the routines are	       :
+; in these include files.  The main files included are: 		       :
+;									       :
+;	File		Contains					       :
+;									       :
+;	msdisk.inc	Disk device driver routines			       :
+;	ms96tpi.inc	Routines for 96tpi drives			       :
+;	msaux.inc	Device driver for the rs-232 serial ports	       :
+;	msclock.inc	Device driver for "clock$" device                      :
+;	mscon.inc	Device driver for "con"                                :
+;	mslpt.inc	Device driver for the printers			       :
+;									       :
+;  Each of these files contain a header section documenting the code	       :
+;  in that file.							       :
+;    Msbio also includes several files for equ's, structure definition,        :
+;  macro definitions, etc.  These are:					       :
+;									       :
+;	msbiomes.inc	 msmacro.inc	devsym.inc			       :
+;		dskprm.inc	   error.inc				       :
+;									       :
+;  Each of these file contains explanitory notes.			       :
+;									       :
+;    The actual code in msbio can be broken down into several piece:	       :
+;									       :
+;	macro definitions	Several marco are defined in msbio.  They      :
+;				are a few odds and end that did not fit        :
+;				anywhere else.				       :
+;									       :
+;	Command Jump Table	List of entry points in the device drivers.    :
+;				See notation below for full explination.       :
+;									       :
+;	Interrupt and Strategy						       :
+;	  Entry points		Calls on the device driver first come to here. :
+;				There is common code with pushes registers and :
+;				the like before jumping to routines in the     :
+;				driver files.  The common exit points are also :
+;				in this file.				       :
+;									       :
+;	Miscellaneous Code	There are several routines and data structure  :
+;				declarations.  See below for details.	       :
+;									       :
+;-------------------------------------------------------------------------------
+
+
+
+;
+; If the variable TEST is non-zero then code for debugging is included.
+; The extra code will make the binary file nuch larger.
+; The symbol is also defined in msequ.inc.  Both must be changed to
+; turn debugging on or off.
+;
+; The level of the debugging is controled by the variable fTestBits in
+; this file.  See the comment preceeding the variable for more information.
+; The actual routines which print the messages are in msmacro.inc
+; See the header comment in this file for more information.
+;
+
+
+;
+; Revision History
+;
+;   REV 2.1	5/1/83 ARR added timer int handler and changed order of AUX
+;		    PRN init for HAL0
+;
+;   REV 2.15	7/13/83 ARR Because of IBM design issues, and that BASCOM
+;		    is ill behaved with respect to the 1CH timer interrupt,
+;		    the timer handler has to be backed out! The intended
+;		    code is commented out and has an ARR 2.15 annotation.
+;		    This means the BIOS will go back to the multiple roll
+;		    over bug.
+;
+;   REV 2.20	8/5/83 ARR IBM makes hardware change.  Now wants to use half
+;		    height drives for HAL0, and back fit for PC/PC XT.	Problem
+;		    with head settle time.  Previous drives got by on a 0
+;		    settle time, 1/2 hight drives need 15 head settle when
+;		    doing WRITEs (0 ok on READ) if the head is being stepped.
+;		    This requires a last track value to be kept so that BIOS
+;		    knows when head is being moved.  To help out
+;		    programs that issue INT 13H directly, the head settle will
+;		    normally be set to 15.  It will be changed to 0 on READs,
+;		    or on WRITEs which do not require head step.
+;
+;   REV 2.21	8/11/83 MZ IBM wants write with verify to use head settle 0.
+;		    Use same trick as above.
+;
+;   REV 2.25	6/20/83 mjb001 added support for 96tpi and salmon
+;
+;   REV 2.30	6/27/83 mjb002 added real-time clock
+;
+;   REV 2.40	7/8/83 mjb003 added volume-id checking and int 2f macro
+;		    definitions push* and pop*
+;
+;   REV 2.41	7/12/83 ARR more 2.X enhancements.  Open/Close media change
+;
+;   REV 2.42	11/3/83 ARR more 2.X enhancements.  Disk OPEN/CLOSE, FORMAT
+;		    code and other misc hooked out to shrink BIOS.  Code for
+;		    Disk OPEN/CLOSE, FORMAT included only with 96tpi disks.
+;
+;   Rev   2.43	12/6/83 MZ Examine boot sectors on hard disks for 16-bit fat
+;		    check.  Examine large fat bit in BPB for walk of media for
+;		    DOS
+;
+;   Rev   2.44	12/9/83 ARR Change to error reporting on INT 17H
+;
+;   Rev   2.45	12/22/83 MZ Make head settle change only when disk parm is 0.
+
+;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+;
+;	IBM ADDRESSES FOR I/O
+;
+;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+
+;Below was moved from sysinit1
+ROMSEGMENT	EQU	0F000H
+MODELBYTE	EQU	DS:BYTE PTR [0FFFEH]
+MODELPCJR	EQU	0FDH
+
+	test=0
+;;Rev 3.30 modification ----------------------------
+	INCLUDE MSGROUP.INC	;DEFINE CODE SEGMENT
+	INCLUDE MSEQU.INC
+	INCLUDE DEVSYM.INC
+	INCLUDE PUSHPOP.INC
+	INCLUDE MSMACRO.INC
+
+	ASSUME	DS:NOTHING,ES:NOTHING
+
+	EXTRN	DSK$IN:NEAR
+	EXTRN	SETPTRSAV:NEAR
+	EXTRN	OUTCHR:NEAR
+	EXTRN	SETDRIVE:NEAR
+	EXTRN	FLUSH:NEAR
+	EXTRN	HARDERR:NEAR
+	EXTRN	HARDERR2:NEAR
+	EXTRN	MAPERROR:NEAR
+	EXTRN	GETBP:NEAR
+	EXTRN	CHECKSINGLE:NEAR
+	EXTRN	CHECK_TIME_OF_ACCESS:NEAR
+	EXTRN	EXIT:NEAR
+	EXTRN	HAS1:NEAR
+	EXTRN	HAS1_res:NEAR
+	EXTRN	READ_SECTOR:NEAR
+	EXTRN	INT_2F_13:FAR
+
+	EXTRN	OLD13:DWORD
+
+;DATA
+	EXTRN	PTRSAV:DWORD
+	EXTRN	START_BDS:WORD
+	EXTRN	FDRIVE1:WORD
+	EXTRN	FDRIVE2:WORD
+	EXTRN	FDRIVE3:WORD
+	EXTRN	FDRIVE4:WORD
+	EXTRN	FLAGBITS:WORD
+	EXTRN	TIM_DRV:BYTE
+	EXTRN	MEDBYT:BYTE
+	EXTRN	DRVMAX:BYTE
+
+	PATHSTART 005,DISK
+	EVENB
+	PUBLIC	ORIG19
+ORIG19	DD	?
+
+	PUBLIC	INT19SEM
+INT19SEM DB	0			; INDICATE THAT ALL INT 19
+					; INITIALIZATION IS COMPLETE
+
+	IRP	AA,<02,08,09,0A,0B,0C,0D,0E,70,72,73,74,76,77>
+	public	Int19OLD&AA
+Int19OLD&AA	dd	-1		;Orignal hw int. vec for INT 19h.
+	ENDM
+
+	EVENB
+	PUBLIC	DSKDRVS
+DSKDRVS DW	FDRIVE1
+	DW	FDRIVE2
+	DW	FDRIVE3
+	DW	FDRIVE4
+	PUBLIC	HDSKTAB
+HDSKTAB DW	HDRIVE
+	DW	DRIVEX
+;* Next area is reseved for mini disk BPB pointers *** 4/7/86
+;* Don't change this pos. Should be add. from DskDrvs *** 4/7/86
+MINI_DISK_BPB_PTRS DB 40 dup (?)   ;4/7/86 - mem res for Mini disk.
+
+	EVENB
+	PUBLIC	INT_2F_NEXT
+INT_2F_NEXT DD	   ?
+
+RET_ADDR    DD	   ?
+
+	PATHEND 005,DISK
+;;End of modification ----------------------------
+
+;  INT19
+;
+;	We "hook" the INT_REBOOT vector, because contrary to IBM documentation,
+;  it does NOT "bootstrap" the machine.  It leaves memory almost untouched.
+;  Since the BIOS_INIT code assumes that certain Interrupt Vectors point to
+;  the ROM_BIOS  we must "unhook" them before issuing the actual INT_REBOOT.
+;  Currently the following vectors need to be unhooked:
+;		  02,08,09,0A,0B,0C,0D,0E,70,72,73,74,75,76,77
+;
+
+Public Int19
+Int19	proc	FAR
+	xor	AX,AX			; get data segment to
+	mov	DS,AX			;   point to the vector table
+	assume	ds:nothing
+	assume	es:nothing
+	les	DI,Old13		; get ES to point to this segment
+	mov	DS:[13h*4],DI		; restore old int13 value
+	mov	DS:[13h*4+2],ES
+
+	cmp	Byte ptr Int19Sem, 0
+	jnz	int19vecs
+	jmp	doint19
+
+;;Dos 3.30 Will not support the PC-Jr
+;;Rev 3.30 modification ----------------------------
+;	ON THE PCJR, DON'T REPLACE ANY VECTORS
+;	MODEL BYTE DEFINITIONS FROM MSSTACK.ASM
+;	MOV	AX,ROMSEGMENT
+;	MOV	DS,AX
+;	MOV	AL,MODELPCJR
+;
+;	CMP	AL,MODELBYTE
+;	JNE	INT19VECS
+;	JMP	DOINT19
+
+
+;Stacks code has changed these hardware interrupt vectors
+;STKINIT in SYSINIT1 will initialzie Int19hOLDxx values.
+int19vecs:
+
+;
+; we now need to unhook all the vector replace to prevent stack overflow
+;
+
+;;Rev 3.30 modification ----------------------------
+	XOR	AX,AX
+	MOV	DS,AX
+
+	IRP	AA,<02,08,09,0A,0B,0C,0D,0E,70,72,73,74,76,77>
+
+	LES	DI,Int19OLD&AA
+
+	mov	ax,es		; Put segment where we can compare it
+	cmp	ax,-1		; OPT 0ffffh is not likely
+	je	skip_int&AA	; OPT could get away without checking
+	cmp	di,-1		; OPT offset here.
+	je	skip_int&AA
+
+	MOV	DS:[AA&H*4],DI
+	MOV	DS:[AA&H*4+2],ES
+skip_int&AA:
+	ENDM
+;;End of modification ----------------------------
+
+doint19:
+	LES	DI,Orig19
+	MOV	DS:[19h*4],DI
+	MOV	DS:[19h*4+2],ES
+
+	INT	19h
+INT19	ENDP
+ASSUME	DS:CODE
+
+;*****************************************************************************
+PUBLIC	DSK$INIT
+DSK$INIT PROC	NEAR
+	PUSH	CS
+	POP	DS
+	MOV	AH,BYTE PTR DRVMAX
+	MOV	DI,OFFSET DskDrvs
+	JMP	SetPTRSAV
+DSK$INIT ENDP
+
+
+;
+; Int 2f handler for external block drivers to communicate with the internal
+; block driver in msdisk. The multiplex number chosen is 8. The handler
+; sets up the pointer to the request packet in [PTRSAV] and then jumps to
+; DSK$IN, the entry point for all disk requests.
+; On exit from this driver (at EXIT), we will return to the external driver
+; that issued this Int 2F, and can then remove the flags from the stack.
+; This scheme allows us to have a small external device driver, and makes
+; the maintainance of the various drivers (DRIVER and msBIO) much easier,
+; since we only need to make changes in one place (most of the time).
+;
+; AL contains the Int2F function:
+;   0 - Check for installed handler - RESERVED
+;   1 - Install the BDS into the linked list
+;   2 - DOS request
+;
+
+MYNUM		EQU	8
+
+Public Int2F_Disk
+Int2F_Disk PROC FAR
+	cmp	ah,MYNUM
+	je	Mine
+	jmp	cs:[Int_2F_Next]	; chain to next Int 2F handler
+Mine:
+	cmp	al,0F8H 		; IRET on reserved functions
+	jb	Do_Func
+	IRET
+Do_Func:
+	or	al,al			; A GET INSTALLED STATE request?
+	jne	Disp_Func
+	mov	al,0FFH
+	IRET
+Disp_Func:
+	Message fTestInit,<"Int2F_disk",cr,lf>
+	cmp	al,1			 ; Request for installing BDS?
+	jne	Do_DOS_Req
+	call	Install_BDS
+	IRET
+
+Do_DOS_Req:
+; Set up pointer to request packet
+	MOV	WORD PTR CS:[PTRSAV],BX
+	MOV	WORD PTR CS:[PTRSAV+2],ES
+	jmp	DSK$IN
+
+Int2F_Disk ENDP
+
+;
+; Install_BDS installs a BDS a location DS:DI into the current linked list of
+; BDS maintained by this device driver. It places the BDS at the END of the
+; list.
+Public Install_BDS
+INSTALL_BDS PROC NEAR
+	message ftestinit,<"Install BDS",cr,lf>
+; ds:di point to BDS to be installed
+	les	si,dword ptr cs:[Start_BDS] ; Start at beginning of list
+	push	es			    ; Save pointer to current BDS
+	push	si
+; es:si now point to BDS in linked list
+Loop_Next_BDS:
+	cmp	si,-1			    ; got to end of linked list?
+	jz	Install_Ret
+; If we have several logical drives using the same physical drive, we must
+; set the I_Am_Mult flag in each of the appropriate BDSs.
+	mov	al,byte ptr ds:[di].DriveNum
+	cmp	byte ptr es:[si].DriveNum,al
+	jnz	Next_BDS
+	message ftestinit,<"Logical Drives",cr,lf>
+	xor	bx,bx
+	mov	bl,fI_Am_Mult
+	or	word ptr ds:[di].flags,bx    ; set flags in both BDSs concerned
+	or	word ptr es:[si].flags,bx
+	mov	bl,fI_Own_Physical
+	xor	bx,-1
+	and	word ptr ds:[di].flags,bx   ; reset that flag for 'new' BDS
+; We must also set the fChangeline bit correctly.
+	mov	bx,word ptr es:[si].flags   ; determine if changeline available
+	and	bl,fChangeline
+	xor	bh,bh
+	or	word ptr ds:[di].flags,bx
+
+Next_BDS:
+; Before moving to next BDS, preserve pointer to current one. This is needed at
+; the end when the new BDS is linked into the list.
+	pop	bx			    ; discard previous pointer to BDS
+	pop	bx
+	push	es
+	push	si
+	mov	bx,word ptr es:[si].link + 2
+	mov	si,word ptr es:[si].link
+	mov	es,bx
+	jmp	short Loop_Next_BDS
+
+Install_Ret:
+	pop	si				; Retrieve pointer to last BDS
+	pop	es				; in linked list.
+	mov	ax,ds
+	mov	word ptr es:[si].link+2,ax	; install BDS
+	mov	word ptr es:[si].link,di
+	mov	word ptr ds:[di].link,-1	; set NEXT pointer to NULL
+	RET
+INSTALL_BDS ENDP
+
+;
+; RE_INIT installs the Int 2F vector that will handle communication between
+; external block drivers and the internal driver. It also installs the
+; Reset_Int_13 interface.  It is called by SYSYINIT
+;
+PUBLIC	RE_INIT
+RE_INIT PROC FAR
+	Message ftestinit,<"REINIT",CR,LF>
+	PUSH	AX
+	PUSH	DS
+	PUSH	DI
+	XOR	DI,DI
+	MOV	DS,DI
+	MOV	DI,2FH*4	    ; point it to Int 2F Vector
+	MOV	AX,WORD PTR DS:[DI]
+	MOV	WORD PTR CS:[INT_2F_NEXT],AX
+	MOV	AX,WORD PTR DS:[DI+2]		   ; preserve old Int 2F vector
+	MOV	WORD PTR CS:[INT_2F_NEXT+2],AX
+
+; INSTALL the Reset_Int_13
+; interface
+
+
+	CLI
+	MOV	Word Ptr DS:[DI],Offset Int_2f_13	  ; install new vectors
+	MOV	Word Ptr DS:[DI+2],CS
+	STI
+	POP	DI
+	POP	DS
+	POP	AX
+	RET
+
+RE_INIT ENDP
+
+;-------------------------------------------------
+;
+;  Ask to swap the disk in drive A:
+; Using a different drive in a one drive system so
+; request the user to change disks
+;
+Public SWPDSK
+SWPDSK	PROC	NEAR
+	mov	al,byte ptr ds:[di].drivelet	; get the drive letter
+	add	al,"A"
+	mov	cs:DRVLET,AL
+	push	ds			; preserve segment register
+	push	cs
+	pop	ds
+	mov	SI,OFFSET SNGMSG	; ds:si -> message
+	push	BX
+	call	WRMSG			;Print disk change message
+	call	FLUSH
+					; wait for a keyboard character
+	xor	AH, AH			; set command to read character
+	int	16h			; call rom-bios
+	POP	BX
+	pop	ds			; restore segment register
+WRMRET:
+	ret
+SWPDSK	ENDP
+
+;----------------------------------------------
+;
+;  WrMsg writes out message pointed to by [SI]
+;
+Public WrMsg
+WRMSG	PROC	NEAR
+	lodsb				; get the next character of the message
+	or	AL,AL			; see fi end of message
+	jz	WRMRET
+	pushf
+	push	CS
+	call	OUTCHR
+	jmp	SHORT WRMSG
+WRMSG	ENDP
+
+	INCLUDE BIOMES.INC
+
+;
+; End of support for multiple floppies with no logical drives
+; This is not 'special' any more because we now have the capability of
+; defining logical drives in CONFIG.SYS. We therefore keep the code for
+; swapping resident ALL the time.
+;
+
+;;Rev 3.30 modification ----------------------------
+;Variables for Dynamic Relocatable modules
+;These should be stay resident.
+
+	public	INT6C_RET_ADDR
+INT6C_RET_ADDR	DD	?		;ret add from INT 6C for P12 mach
+
+	PATHSTART 001,CLK
+;
+;   DATA STRUCTURES FOR REAL-TIME DATE AND TIME
+;
+	public	BIN_DATE_TIME
+	public	MONTH_TABLE
+	public	DAYCNT2
+	public	FEB29
+BIN_DATE_TIME:
+	DB	0		; CENTURY (19 OR 20) OR HOURS (0-23)
+	DB	0		; YEAR IN CENTURY (0-99) OR MINUTES (0-59)
+	DB	0		; MONTH IN YEAR (1-12) OR SECONDS (0-59)
+	DB	0		; DAY IN MONTH (1-31)
+MONTH_TABLE:
+	DW	0		;MJB002 JANUARY
+	DW	31		;MJB002 FEBRUARY
+	DW	59		;MJB002
+	DW	90		;MJB002
+	DW	120		;MJB002
+	DW	151		;MJB002
+	DW	181		;MJB002
+	DW	212		;MJB002
+	DW	243		;MJB002
+	DW	273		;MJB002
+	DW	304		;MJB002
+	DW	334		;MJB002
+DAYCNT2 DW	0000		;MJB002 TEMP FOR CNT OF DAYS SINCE 1-1-80
+FEB29	DB	0		;MJB002 FEBRUARY 29 IN A LEAP YEAR FLAG
+	PATHEND 001,CLK
+
+;;End of modification modification ----------------------------
+
+Public EndFloppy
+EndFloppy Label Byte
+;
+; End of code for virtual floppy drives
+;
+Public EndSwap
+EndSwap Label Byte
+
+	PATHSTART 004,BIO
+
+Public HNUM
+HNUM	DB	0			; number of hardfile (hard drives)
+
+Public HardDrv
+HARDDRV DB	80H			;Physical drive number of first hardfile
+
+
+;
+;  "HDRIVE" is a hard disk with 512 byte sectors
+;
+
+	EVENB
+Public BDSH
+BDSH	DW	-1			; Link to next structure
+	DW	Code
+	DB	80h			; physical drive number
+	DB	"C"                     ; Logical Drive Letter
+Public HDRIVE
+HDRIVE:
+	DW	512
+	DB	1			; Sectors/allocation unit
+	DW	1			; Reserved sectors for DOS
+	DB	2			; No. of allocation tables
+	DW	16			; Number of directory entries
+	DW	0000			; Number of sectors (at 512 bytes each)
+	DB	11111000B		; Media descriptor
+	DW	1			; Number of FAT sectors
+	DW	00			; Sector limit
+	DW	00			; Head limit
+	DW	00			; Hidden sector count
+	DB	0			; TRUE => bigfat
+OPCNTH	DW	0			; Open Ref. Count
+VOLIDH	DB	"NO NAME    ",0         ; Volume ID for this disk
+	DB	3			; Form Factor
+FLAGSH	DW	0020H			; Various Flags
+	dw	40			; number of cylinders
+RecBPBH db	31 dup (?)		; Recommended BPB for drive
+TRACKH	DB	-1			; Last track accessed on this drive
+TIM_LOH DW	-1			; Keep these two contiguous (?)
+TIM_HIH DW	-1
+;
+; End of single hard disk section
+;
+
+
+Public EndOneHard
+EndOneHard Label Byte
+
+
+
+
+;
+;"DRIVEX" is an extra type of drive usually reserved for an
+; additional hard file
+;
+
+	EVENB
+Public BDSX
+BDSX	DW	-1			; Link to next structure
+	DW	Code
+	DB	81h			; physical drive number
+	DB	"D"                     ; Logical Drive Letter
+Public DRIVEX
+DRIVEX:
+	DW	512
+	DB	00			; Sectors/allocation unit
+	DW	1			; Reserved sectors for DOS
+	DB	2			; No. of allocation tables
+	DW	0000			; Number of directory entries
+	DW	0000			; Number of sectors (at 512 bytes each)
+	DB	11111000B		; Media descriptor
+	DW	0000			; Number of FAT sectors
+	DW	00			; Sector limit
+	DW	00			; Head limit
+	DW	00			; Hidden sector count
+	DB	0			; TRUE => bigfat
+OPCNTD	DW	0			; Open Ref. Count
+VOLIDD	DB	"NO NAME    ",0         ; Volume ID for this disk
+	DB	3			; Form Factor
+FLAGSD	DW	0020H			; Various Flags
+	dw	40			; number of cylinders
+RecBPBD db	31 dup (?)		; Recommended BPB for drive
+TRACKD	DB	-1			; Last track accessed on this drive
+TIM_LOD DW	-1			; Keep these two contiguous
+TIM_HID DW	-1
+
+;
+; End of section for two hard disks
+Public EndTwoHard
+EndTwoHard Label Byte
+
+	PATHEND 004,BIO
+
+
+Public TwoHard
+TWOHARD LABEL BYTE
+
+PAGE
+include ms96tpi.inc
+
+;;Rev 3.30 modification ----------------------------
+;Memory allocation for BDSM table.
+	PUBLIC BDSMs
+BDSMs	BDSM_type Max_mini_dsk_num dup (<>)	;currently max. 23
+
+;** End_of_BDSM defined in MSINIT.ASM will be used to set the appropriate
+;** ending address of BDSM table.
+;;End of modification ----------------------------
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;bug005sp
+;
+;;3.3 BUG FIX -SUNILP ------------------------------
+;Paragraph buffer between the BDSMs and MSHARD
+;
+;The relocation code for MSHARD needs this. this cannot be used for 
+;anything. nothing can come before this or after this.....IMPORTANT!!!!
+;don't get too smart and using this buffer for anything!!!!!!
+;
+;	db	16 dup(0)
+;
+;end of bug fix buffer
+;;
+;;3.3 BUG FIX -SUNILP------------------------------
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;bug005sp
+CODE	ENDS
+	END

SRC/BIOS/MSCLOCK.ASM

@@ -0,0 +1,295 @@
+	TITLE MSCLOCK - DOS 3.3
+;----------------------------------------------------------------
+;								:
+;		    CLOCK DEVICE DRIVER 			:
+;								:
+;								:
+;   This file contains the Clock Device Driver. 		:
+;								:
+;   The routines in this files are:				:
+;								:
+;	routine 		function			:
+;	------- 		--------			:
+;	TIM$WRIT		Set the current time		:
+;	TIM$READ		Read the current time		:
+;	Time_To_Ticks		Convert time to corresponding	:
+;				  number of clock ticks 	:
+;								:
+; The clock ticks at the rate of:				:
+;								:
+;	1193180/65536 ticks/second (about 18.2 ticks per second):
+; See each routine for information on the use.			:
+;								:
+;----------------------------------------------------------------
+
+
+	test=0
+	INCLUDE MSGROUP.INC	;DEFINE CODE SEGMENT
+	INCLUDE MSMACRO.INC
+
+	EXTRN EXIT:NEAR
+;
+; DAYCNT is the number of days since 1-1-80.
+; Each time the clock is read it is necessary to check if another day has
+; passed.  The ROM only returns the day rollover once so if it is missed
+; the time will be off by a day.
+;
+	EXTRN DAYCNT:WORD	;MSDATA
+
+;;Rev 3.30 Modification ------------------------------------------------
+; variables for real time clock setting
+	public	HaveCMOSClock
+HaveCMOSClock	db	0	;set by MSINIT.
+	public	base_century
+base_century	db	19
+	public	base_year
+base_year	db	80
+	public	month_tab
+month_tab	db	31,28,31,30,31,30,31,31,30,31,30,31
+
+; The following are indirect intra-segment call addresses. The
+;procedures are defined in MSINIT for relocation.  MSINIT will set these
+;address when the relocation is done.
+	public	BinToBCD
+BinToBCD	dw	0	;should point to Bin_To_BCD proc in MSINIT
+	public	DaycntToDay
+DaycntToDay	dw	0	;should point to Daycnt_to_day in MSINIT
+
+;********************************************************************
+; Indirect call address of TIME_TO_TICKS procedure.
+;This will be used by the relocatable portable suspend/resume code.
+
+	public	TimeToTicks
+TimeToTicks	dw	Time_To_Ticks
+
+;;End of Modification ------------------------------------------------
+
+;--------------------------------------------------------------------
+;
+; Settime sets the current time
+;
+; On entry ES:[DI] has the current time:
+;
+;	number of days since 1-1-80	(WORD)
+;	minutes (0-59)			(BYTE)
+;	hours (0-23)			(BYTE)
+;	hundredths of seconds (0-99)	(BYTE)
+;	seconds (0-59)			(BYTE)
+;
+; Each number has been checked for the correct range.
+;
+	PUBLIC TIM$WRIT
+TIM$WRIT PROC	NEAR
+	ASSUME	DS:CODE
+	mov	AX,WORD PTR ES:[DI]
+	push	AX		;DAYCNT. We need to set this at the very
+				;  end to avoid tick windows.
+;;Rev 3.30 Modification
+	cmp	HaveCMOSClock, 0
+	je	No_CMOS_1
+	mov	al,es:[di+3]		;get binary hours
+	call	BinToBCD		;convert to BCD
+	mov	ch,al			;CH = BCD hours
+	mov	al,es:[di+2]		;get binary minutes
+	call	BinToBCD		;convert to BCD
+	mov	cl,al			;CL = BCD minutes
+	mov	al,es:[di+5]		;get binary seconds
+	call	BinToBCD		;convert to BCD
+	mov	dh,al			;DH = BCD seconds
+	mov	dl,0			;DL = 0 (ST) or 1 (DST)
+	cli				;turn off timer
+	mov	ah,03h			;set RTC time
+	int	1Ah			;call rom bios clock routine
+	sti
+
+;;End of Modification
+No_CMOS_1:
+	mov	CX,WORD PTR ES:[DI+2]
+	mov	DX,WORD PTR ES:[DI+4]
+;;Rev 3.30 Modification
+	call	time_to_ticks	; convert time to ticks
+				;CX:DX now has time in ticks
+	cli			; Turn off timer
+	mov	AH, 1		; command is set time in clock
+	int	1Ah		; call rom-bios clock routines
+	pop	[DAYCNT]
+	sti
+;CMOS clock -------------------------------------
+	cmp	HaveCMOSClock, 0
+	je	No_CMOS_2
+	call	DaycntToDay	; convert to BCD format
+	cli			; Turn off timer
+	mov	AH,05h		; set RTC date
+	int	1Ah		; call rom-bios clock routines
+	sti
+;------------------------------------------------
+
+No_CMOS_2:
+	jmp	EXIT
+TIM$WRIT ENDP
+;;End of Modification
+
+
+
+;
+; convert time to ticks
+; input : time in CX and DX
+; ticks returned in CX:DX
+;
+public time_to_ticks
+TIME_TO_TICKS PROC NEAR
+
+		; first convert from Hour,min,sec,hund. to
+		; total number of 100th of seconds
+	mov	AL,60
+	mul	CH		;Hours to minutes
+	mov	CH,0
+	add	AX,CX		;Total minutes
+	mov	CX,6000 	;60*100
+	mov	BX,DX		;Get out of the way of the multiply
+	mul	CX		;Convert to 1/100 sec
+	mov	CX,AX
+	mov	AL,100
+	mul	BH		;Convert seconds to 1/100 sec
+	add	CX,AX		;Combine seconds with hours and min.
+	adc	DX,0		;Ripple carry
+	mov	BH,0
+	add	CX,BX		;Combine 1/100 sec
+	adc	DX,0
+
+;;Rev 3.30 Modification
+;DX:CX IS TIME IN 1/100 SEC
+	XCHG	AX,DX
+	XCHG	AX,CX		;NOW TIME IS IN CX:AX
+	MOV	BX,59659
+	MUL	BX		;MULTIPLY LOW HALF
+	XCHG	DX,CX
+	XCHG	AX,DX		;CX->AX, AX->DX, DX->CX
+	MUL	BX		;MULTIPLY HIGH HALF
+	ADD	AX,CX		;COMBINE OVERLAPPING PRODUCTS
+	ADC	DX,0
+	XCHG	AX,DX		;AX:DX=TIME*59659
+	MOV	BX,5
+	DIV	BL		;DIVIDE HIGH HALF BY 5
+	MOV	CL,AL
+	MOV	CH,0
+	MOV	AL,AH		;REMAINDER OF DIVIDE-BY-5
+	CBW
+	XCHG	AX,DX		;USE IT TO EXTEND LOW HALF
+	DIV	BX		;DIVDE LOW HALF BY 5
+	MOV	DX,AX
+			; CX:DX is now number of ticks in time
+	ret
+TIME_TO_TICKS ENDP
+;;End of Modification
+
+
+;
+; Gettime reads date and time
+; and returns the following information:
+;
+;	ES:[DI]  =count of days since 1-1-80
+;	ES:[DI+2]=hours
+;	ES:[DI+3]=minutes
+;	ES:[DI+4]=seconds
+;	ES:[DI+5]=hundredths of seconds
+;
+	PUBLIC TIM$READ
+TIM$READ PROC	NEAR
+				; read the clock
+	xor	AH, AH		; set command to read clock
+	int	1Ah		; call rom-bios to get time
+
+	or	al,al		; check for a new day
+	jz	noroll1 	; if al=0 then don't reset day count
+	INC	[DAYCNT]	; CATCH ROLLOVE
+noroll1:
+	MOV	SI,[DAYCNT]
+
+;
+; we now need to convert the time in tick to the time in 100th of
+; seconds.  The relation between tick and seconds is:
+;
+;		 65536 seconds
+;	       ----------------
+;		1,193,180 tick
+;
+; To get to 100th of second we need to multiply by 100. The equation is:
+;
+;	Ticks from clock  * 65536 * 100
+;      ---------------------------------  = time in 100th of seconds
+;		1,193,180
+;
+; Fortunately this fromula simplifies to:
+;
+;	Ticks from clock * 5 * 65,536
+;      --------------------------------- = time in 100th of seconds
+;		59,659
+;
+; The calculation is done by first multipling tick by 5. Next we divide by
+; 59,659.  In this division we multiply by 65,536 by shifting the dividend
+; my 16 bits to the left.
+;
+; start with ticks in CX:DX
+; multiply by 5
+	MOV	AX,CX
+	MOV	BX,DX
+	SHL	DX,1
+	RCL	CX,1		;TIMES 2
+	SHL	DX,1
+	RCL	CX,1		;TIMES 4
+	ADD	DX,BX
+	ADC	AX,CX		;TIMES 5
+	XCHG	AX,DX		
+	
+
+; now have ticks * 5 in DX:AX
+; we now need to multiply by 65,536 and divide by 59659 d.
+
+	mov	CX,59659	; get divisor
+	div	CX
+				; DX now has remainder
+				; AX has high word of final quotient
+	mov	BX,AX		; put high work if safe place
+	xor	AX,AX		; this is the multiply by 65536
+	div	CX		; BX:AX now has time in 100th of seconds
+
+;
+;Rounding based on the remainder may be added here
+;The result in BX:AX is time in 1/100 second.
+	mov	DX,BX
+	mov	CX,200		;Extract 1/100's
+;Division by 200 is necessary to ensure no overflow--max result
+;is number of seconds in a day/2 = 43200.
+	div	CX
+	cmp	DL,100		;Remainder over 100?
+	jb	NOADJ
+	sub	DL,100		;Keep 1/100's less than 100
+NOADJ:
+	cmc			;If we subtracted 100, carry is now set
+	mov	BL,DL		;Save 1/100's
+;To compensate for dividing by 200 instead of 100, we now multiply
+;by two, shifting a one in if the remainder had exceeded 100.
+	rcl	AX,1
+	mov	DL,0
+	rcl	DX,1
+	mov	CX,60		;Divide out seconds
+	div	CX
+	mov	BH,DL		;Save the seconds
+	div	CL		;Break into hours and minutes
+	xchg	AL,AH
+
+;Time is now in AX:BX (hours, minutes, seconds, 1/100 sec)
+
+	push	AX
+	MOV	AX,SI		; DAYCNT
+	stosw
+	pop	AX
+	stosw
+	mov	AX,BX
+	stosw
+	jmp	EXIT
+
+TIM$READ ENDP
+CODE	ENDS
+	END

SRC/BIOS/MSCON.ASM

@@ -0,0 +1,216 @@
+	TITLE MSCON - DOS 3.3
+
+;----------------------------------------------------------------
+;								:
+;	      C O N - CONSOLE DEVICE DRIVER			:
+;								:
+;								:
+;   This file contains the Console Device Driver.  The		:
+; console device driver sends characters to the moniter and	:
+; gets characters from the keyboard.				:
+;								:
+;----------------------------------------------------------------
+
+;;Rev 3.30 Modification
+	test=0
+	INCLUDE MSGROUP.INC	;DEFINE CODE SEGMENT
+	INCLUDE JUMPMAC.INC
+	INCLUDE MSEQU.INC
+	INCLUDE MSMACRO.INC
+
+	EXTRN EXIT:NEAR 	;MSBIO1
+	EXTRN BUS$EXIT:NEAR	;MSBIO1
+
+;DATA
+	EXTRN PTRSAV:DWORD	;MSBIO1
+	EXTRN FHAVEK09:BYTE	;MSDISK
+	EXTRN ALTAH:BYTE	;MSDATA
+;;End of Modification
+
+
+;----------------------------------------------------------------
+;								:
+;		    Console read routine			:
+;								:
+;----------------------------------------------------------------
+;
+	ASSUME DS:CODE		    ; THIS WAS SET BY THE CON DD ENTRY PT
+	PUBLIC	CON$READ
+CON$READ PROC	NEAR
+					; if CX is zero, no characters
+	jcxz	CON$EXIT		;   to be read -- just exit
+CON$LOOP:
+	call	CHRIN			; get char in AL
+	stosb				; store char at ES:DI, specified buffer
+	loop	CON$LOOP		; if CX is non-zero more char to read
+CON$EXIT:
+	Jump	EXIT			; all done, successful return
+CON$READ ENDP
+
+
+;----------------------------------------------------------------
+;								:
+;	    Input single character into AL			:
+;								:
+;----------------------------------------------------------------
+CHRIN	PROC	NEAR
+					; set command to read character
+	xor	AX, AX			;  and clear AL
+	xchg	AL,ALTAH		; get character & zero ALTAH
+	or	AL, AL			; see if buffer has a character
+	jnz	KEYRET			; if so - return this character
+					; if not - read single character
+	int	16h			; call ROM-Bios keyboard routine
+ALT10:
+	or	AX,AX			; Check for non-key after BREAK
+	jz	CHRIN
+	cmp	AX,7200h		; Check for CTRL-PRTSC
+	jnz	ALT15
+	mov	AL,16			; indicate prtsc
+ALT15:
+	or	AL,AL			; special case?
+	jnz	KEYRET			; no, return with character
+	mov	ALTAH, AH		; yes, store special key
+KEYRET:
+	RET
+CHRIN	ENDP
+
+;----------------------------------------------------------------
+;								:
+;	   Keyboard non destructive read, no wait		:
+;								:
+; If bit 10 is set by the DOS in the status word of the request :
+; packet, and there is no character in the input buffer, the	:
+; driver issues a system WAIT request to the ROM. On return	:
+; from the ROM, it returns a 'char-not-found' to the DOS.       :
+;								:
+;----------------------------------------------------------------
+
+CONBUSJ:
+	ASSUME	DS:NOTHING
+	JMP	CONBUS
+
+	ASSUME DS:CODE		    ; THIS WAS SET BY THE CON DD ENTRY PT
+	PUBLIC	CON$RDND
+CON$RDND:
+	mov	AL,[ALTAH]		; first see if there is a
+	or	AL,AL			; character in the buffer?
+	jz	RD1			; with debugging code it is
+	jmp	RDEXIT			;    too far for conditional jump
+
+RD1:
+			     		; set command to 'see if
+	mov	AH, 1	     		;  character available'
+	int	16h	     		; call ROM-BIOS keyboard routine
+	jz	nochr			; with debugging code it is
+	jmp	gotchr			;    to far for conditional jump
+nochr:
+	cmp	fHaveK09, 0
+	jz	CONBUSJ
+	lds	bx,[PTRSAV]		; get pointer to request header
+	ASSUME	DS:NOTHING
+	test	[bx].STATUS,0400H	; System WAIT enabled?
+	jz	CONBUSJ 		; no, get out
+
+	message ftestcon,<"System WAIT stage",cr,lf>
+			      
+	mov	AX, 4100h     		; set command for Wait on External
+			      		; event and condition type to
+			      		; any external event
+	xor	BL,BL	      		; no timeout value
+	int	15h	      		; call rom-bios sleep function
+	message ftestcon,<"Out of wait. AX is ">
+	mnum	ftestcon,ax
+	message ftestcon,<cr,lf>
+	jmp	CONBUS			; after wait exit to con busy
+
+	ASSUME	DS:CODE
+gotchr:
+	or	AX, AX			; check for null after break
+	JNZ	NOTBRK			; no, skip down
+; note: AH is already zero, no need to set command
+	int	16h ;SB 		; yes, read the null
+	Jump	CON$RDND		; and get a real status
+
+NOTBRK:
+	cmp	AX, 7200H		; check for ctrl-prtsc
+	jnz	RDEXIT			; no
+	mov	AL, 16			; yes, indicate ctrl-prtsc
+
+	PUBLIC	RDEXIT
+RDEXIT:
+	lds	BX, [PTRSAV]		; get pointer to request header
+	ASSUME	DS:NOTHING
+	mov	[BX].MEDIA, AL		; move character into req. header
+EXVEC:
+	Jump	EXIT			; all done -- successful return
+CONBUS:
+	ASSUME	DS:NOTHING
+	Jump	BUS$EXIT		; done -- con device is busy
+
+
+;----------------------------------------------------------------
+;								:
+;		Keyboard flush routine				:
+;								:
+;----------------------------------------------------------------
+	ASSUME DS:CODE		    ; THIS WAS SET BY THE CON DD ENTRY PT
+	PUBLIC	CON$FLSH
+CON$FLSH:
+	call	FLUSH
+	Jump	Exit
+
+
+PUBLIC	FLUSH
+FLUSH:
+	mov	[ALTAH], 0	; clear out holding buffer
+
+FlLoop:
+;;Rev 3.30 Modification
+			 	; Is there a char there?
+	mov	AH, 1	 	; command code for check status
+	int	16h	 	; call rom-bios keyboard routine
+				; if z flag is set then no character
+	jz	FlDone		;   is ready, buffer is empty -- get out
+	xor	AH, AH	 	; if zf is nof set, get character
+	int	16h	 	; call rom-bios to get character
+	jmp	FlLoop	       ; repeat until buffer is empty
+FlDone:
+	ret
+;;Rev 3.30 Modification
+
+
+;----------------------------------------------------------------
+;								:
+;	       Console Write Routine				:
+;								:
+;----------------------------------------------------------------
+	ASSUME DS:CODE		    ; THIS WAS SET BY THE CON DD ENTRY PT
+	PUBLIC	CON$WRIT
+CON$WRIT:
+	jcxz	EXVEC			; if CX is zero, get out
+CON$LP:
+	mov	AL,ES:[DI]		; get character
+	inc	DI			; point to next character
+	int	CHROUT			; Output character
+	loop	CON$LP			; repeat until all through
+	Jump	Exit
+
+
+
+;-----------------------------------------------
+;
+;	BREAK KEY HANDLING
+;
+Public CBREAK
+CBREAK:
+	mov	CS:ALTAH, 3		; indicate break key set
+
+
+
+Public INTRET
+INTRET:
+	IRET
+
+CODE	ENDS
+	END

SRC/BIOS/MSDATA.INC

@@ -0,0 +1,882 @@
+;
+; After the boot sector reads in msbio it jumps to this location.  Msbio
+; immediately jumps to initialization code in msinit.
+;
+
+	EXTRN	INIT:NEAR
+
+Public START$
+START$:
+	JMP	INIT			; START$ patch by init to point to
+					; hdrive BPB
+
+
+	PATHSTART 001,BIO
+
+
+;----------------------------------------------------------------------------
+;
+;		Command Jump Tables
+;
+;     These tables hold the entry points for the various service routines
+; for the different drivers.  The index in the table is the command code for
+; that funcion plus two.  For example the command code for Read (input) is 4,
+; The 6th (4 plus 2) entry in the table DSKTBL is DSK$READ - the command to
+; read a disk.	Commands which do not exist for a device are filled with
+; exit (e.g. MediaCheck for CONTBL).  The first entry in the table is the
+; largest command code implemented for that device.  This value is used
+; for error checking.  If new command codes are added then the first entry
+; in the table must be incremented.
+;
+;	BEWARE - These tables overlap somewhat! -c.p.
+;
+
+;
+; Disk:
+;
+
+	ODD
+DSKTBL	LABEL	BYTE
+	DB	24			; This is the size of the table YUK!!!!
+	DW	DSK$INIT		; Code	0: INIT
+	DW	MEDIA$CHK		; code	1: Media Check
+	DW	GET$BPB 		; code	2: BUILD BPB
+	DW	CMDERR			; code	3: IOCTL input
+	DW	DSK$READ		; code	4: INPUT
+	DW	BUS$EXIT		; code	5: NONDESTRUCITVE INPUT, NO WAIT
+	DW	EXIT			; code	6: INPUT STATUS
+	DW	EXIT			; code	7: INPUT FLUSH
+	DW	DSK$WRIT		; code	8: OUTPUT
+	DW	DSK$WRITV		; code	9: OUTPUT with verify
+	DW	EXIT			; code 10: OUTPUT STATUS
+	DW	EXIT			; code 11: OUTPUT FLUSH
+	DW	CMDERR			; code 12: IOCTL output
+Public TABLE_PATCH
+TABLE_PATCH LABEL WORD			;ARR 2.42
+	DW	DSK$OPEN		; code 13: DEVICE OPEN
+	DW	DSK$CLOSE		; code 14: DEVICE CLOSE
+	DW	DSK$REM 		; code 15: REMOVABLE MEDIA
+	dw	exit
+	dw	exit
+	dw	exit
+	DW	GENERIC$IOCTL
+	dw	exit
+	dw	exit
+	dw	exit
+	dw	IOCTL$GETOWN
+	dw	IOCTL$SETOWN
+
+;
+; Console:
+;
+
+	ODD
+CONTBL	LABEL	BYTE
+	DB	10
+	DW	EXIT
+	DW	EXIT
+	DW	EXIT
+	DW	CMDERR
+	DW	CON$READ
+	DW	CON$RDND
+	DW	EXIT
+	DW	CON$FLSH
+	DW	CON$WRIT
+	DW	CON$WRIT
+	DW	EXIT
+
+;
+; Auxilary:
+;
+
+	ODD
+AUXTBL	LABEL	BYTE
+	DB	10
+	DW	EXIT
+	DW	EXIT
+	DW	EXIT
+	DW	CMDERR
+	DW	AUX$READ
+	DW	AUX$RDND
+	DW	EXIT
+	DW	AUX$FLSH
+	DW	AUX$WRIT
+	DW	AUX$WRIT
+	DW	AUX$WRST
+
+;
+; Clock:
+;
+
+	ODD
+TIMTBL	LABEL	BYTE
+	DB	9
+	DW	EXIT
+	DW	EXIT
+	DW	EXIT
+	DW	CMDERR
+	DW	TIM$READ
+	DW	BUS$EXIT
+	DW	EXIT
+	DW	EXIT
+	DW	TIM$WRIT
+	DW	TIM$WRIT
+
+;
+; Printer:
+;
+
+	ODD
+PRNTBL	LABEL	BYTE
+	DB	24
+	DW	EXIT			;INIT
+	DW	EXIT
+	DW	EXIT
+	DW	CMDERR
+	DW	EXIT$ZER		;INDICATE ZERO CHARS READ
+	DW	BUS$EXIT
+	DW	EXIT
+	DW	EXIT
+	DW	PRN$WRIT
+	DW	PRN$WRIT
+	DW	PRN$STAT
+	DW	EXIT
+	DW	EXIT
+	DW	EXIT
+	DW	EXIT
+	DW	EXIT
+	DW	PRN$TilBusy
+	DW	EXIT
+	DW	EXIT
+	DW	PRN$GenIOCTL
+	dw	exit
+	dw	exit
+	dw	exit
+	dw	CMDERR
+	dw	CMDERR
+
+
+	EVENB
+Public Old13
+OLD13	label	DWORD
+	db	'5986'                  ;Code for 3.30
+
+
+Public Orig13
+ORIG13	label	DWORD
+	db	'21',0,0                ;Code for 3.30
+
+
+;
+; PTRSAV - pointer save
+;
+;   This variable holds the pointer to the Request Header passed by a
+; program wishing to use a device driver.  When the strategy routine is
+; called it puts the address of the Request header in this variable and
+; returns.
+;
+
+	EVENB
+PUBLIC	PTRSAV
+PTRSAV	DD	0
+
+
+;
+; Buffer for the AUX device driver
+;
+
+;;Rev 3.30 Modification
+	PUBLIC	AUXBUF
+AUXBUF	DB	0,0,0,0   ;SET OF 1 BYTE BUFFERS FOR COM 1,2,3, AND 4
+
+
+	EVENB
+	PUBLIC PREVOPER,NUMBER_OF_SEC
+;;End of Modification
+PrevOper	DW	?	; Holds ROM DISK INT request (i.e. Register AX).
+Number_Of_Sec	DB	?	; Holds number of sectors to read on an ECC error
+
+
+;;Rev 3.30 Modification
+	IF	($-CODE) GT 100H
+	    %OUT VDISK BUFFER NOT CORRECTLY LOCATED
+	ELSE
+	    ORG 100H
+	ENDIF
+	PUBLIC	VDISK_AREA
+VDISK_AREA DB	108 DUP(0)		;FOR USE BY VDISK
+;;End of Modification
+
+
+;
+; AUXNUM holds the number of the printer or AUX device requested.  For
+; example if printer 2 was called (PRN2$IN) AUXNUM is set to be one; with
+; line printer 3 AUXNUM is set to 2.  With this set the printer device driver
+; can tell which printer to command applies to.
+;
+; WARNING!!!  These are addressed together in GETDX
+;
+
+	EVENB
+AUXNUM	DB	0
+	DB	0
+
+
+;
+; Device Header for the CON Device Driver
+;
+
+	EVENB
+PUBLIC	CONHeader
+CONHeader LABEL   WORD
+	DD	AUXDEV2
+	DW	1000000000010011B	; Con in and con out + special
+	DW	STRATEGY		; Strategy entry point
+	DW	CON$IN			; interrupt entry point
+	DB	'CON     '              ; device name
+
+
+;
+; Device Header for device "AUX"
+;
+
+	EVENB
+	PUBLIC	AUXDEV2
+AUXDEV2  LABEL	 WORD			 ;HEADER FOR DEVICE "AUX"
+	DD	PRNDEV2
+	DW	1000000000000000B	; attribute word, character device
+	DW	STRATEGY		; device strategy routine
+	DW	AUX0$IN 		; device interrupt routine
+	DB	'AUX     '              ; device name
+
+
+;
+; Device Header for device PRN
+;
+
+	EVENB
+	PUBLIC	PRNDEV2
+PRNDEV2  LABEL	 WORD			 ;HEADER FOR DEVICE "PRN"
+	DD	TIMDEV
+	DW	CharDev + OutTilBusy + Dev320
+	DW	STRATEGY
+	DW	PRN0$IN
+	DB	'PRN     '
+
+
+;
+; Device Header for device CLOCK$
+;
+
+	EVENB
+	PUBLIC TIMDEV
+TIMDEV	LABEL	WORD
+	DD	DSKDEV
+	DW	1000000000001000B
+	DW	STRATEGY
+	DW	TIM$IN
+	DB	'CLOCK$  '
+
+
+;
+; Device Header for disk devices
+;
+;	Device attribute bits:
+;		Bit 6 - DOS 3.2 Bit
+;
+
+	EVENB
+PUBLIC	DSKDEV
+DSKDEV	LABEL	WORD
+	DD	COM1DEV
+	DW	0000100001000000B	; DOS 3.2
+	DW	STRATEGY		; strategy routine
+	DW	DSK$IN			; Interrupt entry point
+
+
+;
+; maximum number of drives
+;
+
+DRVMAX	DB	4
+Public DRVMAX
+
+
+;
+; Last drive accessed
+;
+
+	PUBLIC STEP_DRV
+STEP_DRV	DB     -2		; ARR 2.20 LAST DRIVE ACCESSED
+
+Public Phys_Drv
+Phys_Drv	DB	0		; Used by setdrvie for getting
+					; BDS for logical drive, or physical
+					; drive. 0 => use logical
+					;	 1 => use physical
+
+Public fHave96
+fHave96 DB	0			; Flag to indicate presence of
+					;   96tpi support
+
+Public Single
+Single		DB	0		; Used to detect single drive systems
+
+Public fHaveK09
+fHaveK09	DB	0		;Indicates if this is a K09 or not
+					; used by console driver.
+Public NEW_ROM
+NEW_ROM 	DB	0		;Set to 1 if we have a ROM that can
+					; handle strange media layouts.
+
+	PUBLIC FSETOWNER
+fSetOwner	db	?		;=1 if we are setting the owner of a
+					;drive. (Examined by CheckSingle).
+	public	Secrete_Code
+Secrete_Code	dw	'jk'            ;Code for 3.30.
+
+
+;
+; Device Header for device "COM1"
+;
+
+	EVENB
+Public COM1DEV
+COM1DEV LABEL	WORD
+	DD	LPT1DEV
+	DW	1000000000000000B	; attribute word, character device
+	DW	STRATEGY		; device strategy routine
+	DW	AUX0$IN 		; device interrupt routine
+	DB	'COM1    '              ; device name
+
+
+;
+; Device Header for device LPT1
+;
+
+	EVENB
+Public LPT1DEV
+LPT1DEV LABEL	WORD
+	DD	LPT2DEV
+	DW	CharDev + OutTilBusy + Dev320
+	DW	STRATEGY
+	DW	PRN1$IN
+	DB	'LPT1    '
+
+
+;
+; Device Header for device LPT2
+;
+
+	EVENB
+Public Lpt2Dev
+LPT2DEV LABEL	WORD
+	DD	LPT3DEV
+	DW	CharDev + OutTilBusy + Dev320
+	DW	STRATEGY
+	DW	PRN2$IN
+	DB	'LPT2    '
+
+;
+; Device Header for device LPT3
+;
+
+	EVENB
+Public Lpt3Dev
+LPT3DEV LABEL	WORD
+	DD	COM2DEV
+	DW	CharDev + OutTilBusy + Dev320
+	DW	STRATEGY
+	DW	PRN3$IN
+	DB	'LPT3    '
+
+
+;
+; Device Header for device "COM2"
+;
+
+	EVENB
+Public Com2Dev
+COM2DEV LABEL	WORD
+	dd	COM3DEV
+	DW	1000000000000000B	; attribute word, character device
+	DW	STRATEGY		; device strategy routine
+	DW	AUX1$IN 		; device interrupt routine
+	DB	'COM2    '              ; device name
+
+;;Rev 3.30 Modification
+;
+; Device header for device "COM3"
+;
+	EVENB
+	PUBLIC  COM3DEV
+COM3DEV LABEL   WORD
+	dd	COM4DEV
+	dw	1000000000000000b	; character device attribute
+	dw	STRATEGY
+	dw	AUX2$IN			; com3 == aux2
+	db	'COM3    '
+
+;
+; Device header for device "COM4"
+;
+	EVENB
+	PUBLIC  COM4DEV
+COM4DEV LABEL   WORD
+	dw	-1,CODE
+	dw	1000000000000000b	; character device attribute
+	dw	STRATEGY
+	dw	AUX3$IN			; com4 == aux3
+	db	'COM4    '
+
+;;End of Modification
+
+
+; Hard-wire the link to the next Int2f handler.
+;;Rev 3.30 Modification
+		EVENB
+PUBLIC	Next2f_13
+NEXT2F_13	LABEL	WORD
+	EXTRN INT2F_DISK:FAR		;MSBIO2
+		DD	INT2F_DISK
+
+
+;
+; Start of linked list of BDS's
+;
+
+		EVENB
+Public Start_BDS
+START_BDS LABEL WORD
+       DD      BDS1	       ;START OF BDS LINKED LIST.
+;;End of Modification
+
+
+;
+; Some floppy drives do not have changeline support.  The result is a
+; large amount of inefficiency in the code.  A media-check always returns
+; "I don`t know".  This cause DOS to reread the FAT on every access and
+; always discard any cached data.
+;    We get around this inefficiency by implementing a "Logical Door Latch".
+; The following three items are used to do this.  The logical door latch is
+; based on the premise that it is not physically possible to change floppy
+; disks in a drive in under two seconds (most people take about 10).  The
+; logical door latch is implemented by saving the time of the last successful
+; disk operation (in the value TIM_DRV).  When a new request is made the
+; current time is compared to the saved time.  If less than two seconds have
+; passed then the value "No Change" is returned.  If more than two seconds
+; have passed the value "Don't Know" is returned.
+;    There is one complecation to this algorithm.  Some programs change the
+; value of the timer.  In this unfortunate case we have an invalid timer.
+; This possiblity is detected by counting the number of disk operations
+; which occur without any time passing.  If this count exceeds the value of
+; "AccessMax" we assume the counter is invalid and always return "Don't
+; Know".  The variable "AccessCount" is used to keep track of the number
+; of disk operation which occur without the time changing.
+;
+
+	PUBLIC ACCESSCOUNT
+AccessCount db	0			; number of times media check called
+
+	PUBLIC TIM_DRV
+TIM_DRV DB	-1			; time when last disk I/O was performed
+
+	PUBLIC FLAGBITS
+FlagBits	dw	0		; Bits to set in flag field when doing
+					; a Set_Changed_DL
+
+	PUBLIC	MEDBYT
+MedByt		DB	?		; hold media byte from floppy
+
+		EVENB
+	PUBLIC WRTVERIFY
+WRTVERIFY LABEL WORD
+
+	PUBLIC RFLAG
+RFLAG		DB	ROMRead 		;2 for read, 3 for write
+VERIFY		DB	0			;1 if verify after write
+
+	PUBLIC SECCNT
+SECCNT		DW	0
+
+
+Public HARDNUM
+HARDNUM 	DB	99		;logical drive number of first hardfile
+
+;
+; Some of the older versions of the IBM rom-bios always assumed a seek would
+; have to be made to read the diskette.  Consequently a large head settle
+; time was always used in the I/O operations.  To get around this problem
+; we need to continually adjust the head settle time.  The following
+; algorithm is used:
+;
+;   Get the current head settle value.
+;   If it is 1, then
+;	set slow = 15
+;   else
+;	set slow = value
+;   ...
+;   if we are seeking and writing then
+;	use slow
+;   else
+;	use fast
+;   ...
+;   restore current head settle value
+;
+
+	PUBLIC MOTORSTARTUP,SETTLECURRENT,SETTLESLOW
+MotorStartup	db  ?			; value from table
+SettleCurrent	db  ?			; value from table
+SettleSlow	db  ?			; slow settle value
+
+NextSpeed   DB	?			; value of speed to be used
+
+	public	save_head_sttl
+Save_head_sttl	db  ?		;used by READ_SECTOR routine
+
+
+Public EOT
+EOT	    DB	9
+
+;
+; pointer to Disk Parameter Table
+;
+
+		EVENB
+	PUBLIC DPT
+DPT	    DD	?
+
+;
+; The following two sets of variables are used to hold values for
+; disk I/O operations
+; Keep the next two items contiguous - see IOCTL_Block for reason
+
+	PUBLIC CURSEC,CURHD,CURTRK,SPSAV
+CURSEC	DB	0			; current sector
+CURHD	DB	0			; current head
+CURTRK	DW	0			; current track
+SPSAV	DW	0			; save the stack pointer
+
+;
+; The following are used for IOCTL function calls
+;
+
+	PUBLIC FORMT_EOT,HDNUM,TRKNUM,GAP_PATCH 
+FORMT_EOT	DB	8		    ; EOT used for format
+HDNUM		DB	0		    ; Head number
+TRKNUM		DW	0		    ; Track being manipulated
+GAP_PATCH	DB	50h		    ; Format gap patched into DPT
+
+;
+; Disk errors returned from the IBM rom
+;
+
+Public ERRIN
+ERRIN	LABEL	BYTE
+	DB	80H			; no response
+	DB	40H			; seek failure
+	DB	10H			; bad CRC
+	DB	8			; DMA overrun
+	DB	6			; media change
+	DB	4			; sector not found
+	DB	3			; write attempt to write-protect disk
+	PUBLIC LSTERR
+LSTERR	DB	0			; all other errors
+
+;
+; returned error code corresponding to above errors
+;
+
+Public ERROUT
+ERROUT	LABEL	BYTE
+	DB	2			; no response
+	DB	6			; seek failure
+	DB	4			; bad CRC
+	DB	4			; DMA overrun
+	DB	15			; invalid media change
+	DB	8			; sector not found
+	DB	0			; write attempt on write-protect disk
+	DB	12			; general error
+
+	PUBLIC NUMERR
+NUMERR	=	ERROUT-ERRIN
+
+
+;-------------------------------------------------------------
+;
+; DiskSector is a 512 byte sector into which the boot sector
+; is read.  It is also used as read sector for DMA check for
+; hard disk.
+
+
+Public DiskSector
+DiskSector  db	11 dup(?)	   ; take care of 3 jump bytes plus OEM name.
+	PUBLIC BPB_IN_SECTOR
+BPB_In_Sector	dw  ?
+	PUBLIC SECPERCLUSINSECTOR
+SECPERCLUSINSECTOR	DB	?
+	dw	?
+	db	?
+	dw	?
+	dw	?
+	PUBLIC MEDIABYTE
+mediabyte   db	    ?
+	dw	?
+	dw	?
+	dw	?
+	dw	?
+	db	?
+	db	512-($-DiskSector) dup (?)
+
+;---------------------------------------------------------------------
+;
+;	The "BDS"'s contain information for each drive in the system.
+;  There is one BDS for each logical drvie in the system.  The BDS's
+;  are all linked together in a chain.	The BDS contain various values
+;  important to the disk drive. Various values are updated whenever actions
+;  are performed.  For example if a drive is read from the last time
+;  accessed fields are updated to the current time.
+;	Initial values:
+;    *	Sectors/Alloc. unit in BPB initially set to -1 to signify that
+;	the BPB has not been filled.
+;    *	Link is set to -1 to signify end of list.
+;    *	number of cylinders in MaxParms initialized to -1 to indicate
+;	that the parameters have not been set.
+;
+;  Start_BDS contains a pointer to the first BDS.  It is through this
+;  pointer that routines find particular BDS (see SetDrive to see how
+;  this is done).
+;
+
+	EVENB
+BDS1	LABEL	WORD
+	DD	BDS2			;LINK TO NEXT STRUCTURE
+	DB	0			;ROM DISK INT Drive Number
+	DB	0			;Logical Drive Letter
+	PUBLIC	FDRIVE1 
+FDRIVE1 DW	512			;Physical sector size in bytes
+	DB	-1			;Sectors/allocation unit
+	DW	1			;Reserved sectors for DOS
+	DB	2			;No. allocation tables
+	DW	64			;Number directory entries
+	DW	9*40			;Number sectors (at 512 bytes ea.)
+	DB	00000000B		;Media descriptor, initially 00H.
+	DW	2			;Number of FAT sectors
+	DW	9			;Sector limit
+	DW	1			;Head limit
+	DW	0			;Hidden sector count
+	DB	0			; TRUE => Large fats
+OPCNT1	DW	0			;Open Ref. Count
+VOLID1	DB	"NO NAME    ",0         ;Volume ID for this disk
+	DB	3			;Form Factor
+FLAGS1	DW	0020H			;Various Flags
+;	DB	9 dup (0)		;Reserved for future use
+	dw	40			; number of cylinders
+RecBPB1 DW	512			;Physical sector size in bytes
+	DB	1			;Sectors/allocation unit
+	DW	1			;Reserved sectors for DOS
+	DB	2			;No. allocation tables
+	DW	0E0H			;NUMBER DIRECTORY ENTRIES
+	DW	9*40			;Number sectors (at 512 bytes ea.)
+	DB	0F0h			;Media descriptor, initially 00H.
+	DW	2			;Number of FAT sectors
+	DW	9			;Sector limit
+	DW	2			;HEAD LIMIT
+	DW	0			;Hidden sector count
+	DB	12 DUP (?)
+TRACK1	DB	-1			;Last track accessed on this drive
+TIM_LO1 DW	-1			;Keep these two contiguous (?)
+TIM_HI1 DW	-1
+
+	EVENB
+BDS2	LABEL	WORD
+	DD	BDS3			;LINK TO NEXT STRUCTURE
+	DB	0			;INT 13 DRIVE NUMBER
+	DB	0			;Logical Drive Letter
+	PUBLIC	FDRIVE2 
+FDRIVE2 DW	512			;Physical sector size in bytes
+	DB	-1			;Sectors/allocation unit
+	DW	1			;Reserved sectors for DOS
+	DB	2			;No. allocation tables
+	DW	64			;Number directory entries
+	DW	9*40			;Number sectors (at 512 bytes ea.)
+	DB	00000000B		;Media descriptor, initially 00H.
+	DW	2			;Number of FAT sectors
+	DW	9			;Sector limit
+	DW	1			;Head limit
+	DW	0			;Hidden sector count
+	DB	0			; TRUE => Large fats
+OPCNT2	DW	0			;Open Ref. Count
+VOLID2	DB	"NO NAME    ",0         ;Volume ID for this disk
+	DB	3			;Form Factor
+FLAGS2	DW	0020H			;Various Flags
+;	DB	9 dup (0)		;Reserved for future use
+	dw	40			; number of cylinders
+RecBPB2 DW	512			;Physical sector size in bytes
+	DB	1			;Sectors/allocation unit
+	DW	1			;Reserved sectors for DOS
+	DB	2			;No. allocation tables
+	DW	0E0H			;NUMBER DIRECTORY ENTRIES
+	DW	9*40			;Number sectors (at 512 bytes ea.)
+	DB	0F0h			;Media descriptor, initially 00H.
+	DW	2			;Number of FAT sectors
+	DW	9			;Sector limit
+	DW	2			;HEAD LIMIT
+	DW	0			;Hidden sector count
+	DB	12 DUP (?)
+TRACK2	DB	-1			;Last track accessed on this drive
+TIM_LO2 DW	-1			;Keep these two contiguous (?)
+TIM_HI2 DW	-1
+
+	EVENB
+BDS3	LABEL	WORD
+	DD	BDS4			;LINK TO NEXT STRUCTURE
+	DB	0			;INT 13 DRIVE NUMBER
+	DB	0			;Logical Drive Letter
+	PUBLIC	FDRIVE3
+FDRIVE3 DW	512			;Physical sector size in bytes
+	DB	-1			;Sectors/allocation unit
+	DW	1			;Reserved sectors for DOS
+	DB	2			;No. allocation tables
+	DW	64			;Number directory entries
+	DW	9*40			;Number sectors (at 512 bytes ea.)
+	DB	00000000B		;Media descriptor, initially 00H.
+	DW	2			;Number of FAT sectors
+	DW	9			;Sector limit
+	DW	1			;Head limit
+	DW	0			;Hidden sector count
+	DB	0			; TRUE => Large fats
+OPCNT3	DW	0			;Open Ref. Count
+VOLID3	DB	"NO NAME    ",0         ;Volume ID for this disk
+	DB	3			;Form Factor
+FLAGS3	DW	0020H			;Various Flags
+;	DB	9 dup (0)		;Reserved for future use
+	dw	40			; number of cylinders
+RecBPB3 DW	512			;Physical sector size in bytes
+	DB	1			;Sectors/allocation unit
+	DW	1			;Reserved sectors for DOS
+	DB	2			;No. allocation tables
+	DW	0E0H			;NUMBER DIRECTORY ENTRIES
+	DW	9*40			;Number sectors (at 512 bytes ea.)
+	DB	0F0h			;Media descriptor, initially 00H.
+	DW	2			;Number of FAT sectors
+	DW	9			;Sector limit
+	DW	2			;HEAD LIMIT
+	DW	0			;Hidden sector count
+	DB	12 DUP (?)
+TRACK3	DB	-1			;Last track accessed on this drive
+TIM_LO3 DW	-1			;Keep these two contiguous (?)
+TIM_HI3 DW	-1
+
+	EVENB
+BDS4	LABEL	WORD
+	DW	-1			;Link to next structure
+	DW	Code
+	DB	0			;INT 13 DRIVE NUMBER
+	DB	0			;Logical Drive Letter
+	PUBLIC	FDRIVE4
+FDRIVE4 DW	512			;Physical sector size in bytes
+	DB	-1			;Sectors/allocation unit
+	DW	1			;Reserved sectors for DOS
+	DB	2			;No. allocation tables
+	DW	64			;Number directory entries
+	DW	9*40			;Number sectors (at 512 bytes ea.)
+	DB	00000000B		;Media descriptor, initially 00H.
+	DW	2			;Number of FAT sectors
+	DW	9			;Sector limit
+	DW	1			;Head limit
+	DW	0			;Hidden sector count
+	DB	0			; TRUE => Large fats
+OPCNT4	DW	0			;Open Ref. Count
+VOLID4	DB	"NO NAME    ",0         ;Volume ID for this disk
+	DB	3			;Form Factor
+FLAGS4	DW	0020H			;Various Flags
+;	DB	9 dup (0)		;Reserved for future use
+	dw	40			; number of cylinders
+;;Rev 3.30 Modification
+RECBPB4 DW	512			;BYTES PER SECTOR
+	DB	1			;SECTORS/ALLOCATION UNIT
+	DW	1			;RESERVED SECTORS FOR DOS
+	DB	2			;NO. ALLOCATION TABLES
+	DW	0E0H			;NUMBER DIRECTORY ENTRIES
+	DW	9*40			;NUMBER SECTORS (AT 512 BYTES EA.)
+	DB	0F0H			;MEDIA DESCRIPTOR, INITIALLY F0H.
+	DW	2			;NUMBER OF FAT SECTORS
+	DW	9			;SECTOR LIMIT
+	DW	2			;HEAD LIMIT
+	DW	0			;HIDDEN SECTOR COUNT
+	DB	12 DUP (?)
+;;End of Modification
+TRACK4	DB	-1			;Last track accessed on this drive
+TIM_LO4 DW	-1			;Keep these two contiguous (?)
+TIM_HI4 DW	-1
+
+
+bpbType struc
+spf	db	?
+spt	db	?
+cdire	db	?
+csec	dw	?
+spa	db	?
+chead	db	?
+bpbType ends
+	PUBLIC SM92
+sm92	bpbType <3,9,70H,2*9*80,2,2>
+
+
+;
+; ALTAH is a single character buffer used to handle special keys.
+;
+
+	PUBLIC	ALTAH
+ALTAH	DB	0			;Special key handling
+
+
+;
+; The following variable can be modified via IOCTL sub-function 16. In this
+; way, the wait can be set to suit the speed of the particular printer being
+; used. One for each printer device.
+;
+
+	PUBLIC PRINTDEV
+PRINTDEV	DB	0		; Index into following array
+
+		EVENB
+	PUBLIC WAIT_COUNT
+WAIT_COUNT	DW	4 dup (50h)	; Array of Retry counts for printer
+
+
+;
+; DAYCNT is the number of days since 1-1-80.
+; Each time the clock is read it is necessary to check if another day has
+; passed.  The ROM only returns the day rollover once so if it is missed
+; the time will be off by a day.
+;
+
+		EVENB
+Public DAYCNT
+DAYCNT	DW	0
+
+
+;
+; The following variables and two routines (MSGOUT and MSGNUM) are used
+; with the debug routines to print numbers and messages on the screen.
+;
+; The variable fTestBits controls the level of debugging in the system.
+; See the comments and "equ's" in msmacro.inc for an explination of
+; how to control the level of debugging.  In a nutshell, setting
+; fTestBits to fTestALL prints all the debugging messages.  Setting
+; it to fTestDisk prints all disk related messages, etc.
+;
+
+if test
+Public NumBuf
+NumBuf	DB	5 dup (?)
+Public Digits
+Digits	DB	"0123456789ABCDEF"
+Public fTestBits
+FTESTBITS   DW	    fTestDISK
+endif
+
+
+	PATHEND 001,BIO

SRC/BIOS/MSEQU.INC

@@ -0,0 +1,65 @@
+
+; file: msequ.asm contains various equ's used in the bio.  The values
+; are explained below.
+;
+
+;IBMCOPYRIGHT	EQU	0
+fTOOBIG 	EQU	80h
+fBIG		EQU	40h
+ROMStatus	EQU	1
+ROMRead 	EQU	2
+ROMWrite	EQU	3
+ROMVerify	EQU	4
+ROMFormat	EQU	5
+vid_size	EQU 12
+
+include msbds.inc    ; various equates for bds
+include version.inc
+
+
+IF IBMCOPYRIGHT
+SYSIZE=200H		      ;NUMBER OF PARAGRAPHS IN SYSINIT MODULE	  ;;Rev 3.30 Modification
+ELSE
+SYSIZE=203H
+ENDIF
+RSINIT=0A3H		      ; RS-232 initialization			  ;;End of Modification
+LF=10			      ; line feed
+CR=13			      ; carriage return
+BACKSP=8		      ; backspace
+BRKADR=1BH * 4		      ; 006C  1BH break vector address
+TIMADR=1CH * 4		      ; 0070  1CH timer interrupt
+DSKADR=1EH * 4		      ; address of ptr to disk parameters
+SEC9=522H		      ; address of disk parameters
+HEADSETTLE=SEC9+9	      ; address of head settle time
+NORMSETTLE=15		      ; Normal head settle
+SPEEDSETTLE=0		      ; Speed up settle time
+INITSPOT=534H		      ; IBM wants 4 zeros here
+AKPORT=20H
+EOI=20H
+CMDLEN	=	    0		; length of this command
+UNIT	=	    1		; sub unit specifier
+CMD	=	    2		; command code
+STATUS	=	    3		; status
+MEDIA	=	    13		; media descriptor
+TRANS	=	    14		; transfer address
+COUNT	=	    18		; count of blocks or characters
+START	=	    20		; first block to transfer
+EXTRA	=	    22		; usually a pointer to Vol Id for error 15
+CHROUT	=	    29H
+MAXERR	=	     5
+LSTDRV	=	     504H
+
+				; location of boot sector on startup
+BootBias	=   200h
+
+NotBusyStatus	=	10000000B	    ; not busy
+AckStatus	=	01000000B	    ; acknowledge (for what?)
+NoPaperStatus	=	00100000B	    ; No more paper
+SelectedStatus	=	00010000B	    ; The printer said it was selected
+IOErrStatus	=	00001000B	    ; Some kinda error
+RESERVED	=	00000110B	    ; NOPs
+TimeOutStatus	=	00000001B	    ; time out.
+
+PATHGEN 	=	1
+
+

SRC/BIOS/MSEXTRN.INC

@@ -0,0 +1,72 @@
+
+;
+; file: msextrn.asm
+;
+;  This file list the external variable used in the bio.
+;
+
+	EXTRN	ORIG13:DWORD,ORIG19:DWORD
+	EXTRN	COM2DEV:WORD,COM1DEV:WORD
+	EXTRN	COM4DEV:WORD,COM3DEV:WORD				  ;3.30
+	EXTRN	LPT3DEV:WORD,LPT2DEV:WORD,LPT1DEV:WORD
+	EXTRN	HARDDRV:BYTE,HARDNUM:BYTE,DRVMAX:BYTE,HDSKTAB:WORD
+	EXTRN	DSKDRVS:WORD,HNUM:BYTE,EOT:BYTE,FHAVE96:BYTE
+	EXTRN	REAL13:DWORD,DAYCNT:WORD,CONHeader:WORD
+	EXTRN	TWOHARD:BYTE,INT_2F_NEXT:DWORD
+	EXTRN	BDSH:WORD,BDSX:WORD,START_BDS:DWORD
+	EXTRN	FHAVEK09:BYTE, NEW_ROM:BYTE
+	EXTRN	Single:BYTE
+	EXTRN	BDSMs:BYTE		;for Mini Disk  4/7/86	  ;3.30
+	EXTRN	HaveCMOSClock:byte	;set by MSINIT. Used by MSCLOCK.AS;3.30 M
+	EXTRN	BinToBCD:word		;set by MSINIT. Used by MSCLOCK.AS;3.30 M
+	EXTRN	DaycntToDay:word	;set by MSINIT. Used by MSCLOCK.AS;3.30 M
+
+	if test
+	  IFNDEF NUMBUF 						  ;3.30
+	    EXTRN   NUMBUF:BYTE,DIGITS:BYTE,FTESTBITS:WORD
+	  ENDIF 							  ;3.30
+	endif
+
+	EXTRN	START$:NEAR,ERROUT:NEAR,BLOCK13:FAR,INT19:FAR
+	EXTRN	INTRET:NEAR,HDRIVE:NEAR,DRIVEX:NEAR,INT13:FAR,CBREAK:NEAR,OUTCHR:NEAR
+	EXTRN	DISKRD:NEAR,MEDIA_PATCH:NEAR,GETBP1_PATCH:NEAR
+	EXTRN	SET_PATCH:NEAR,DISKIO_PATCH:NEAR,DSKERR:NEAR,INIT_PATCH:NEAR
+	EXTRN	TABLE_PATCH:NEAR,EXIT:NEAR,CHANGED_PATCH:NEAR
+	EXTRN	ERRIN:NEAR,GETBP:NEAR,SWPDSK:NEAR			  ;3.30
+	EXTRN	OUTCHR:NEAR,WRMSG:NEAR,time_to_ticks:near
+	EXTRN	INT2F_DISK:NEAR,INSTALL_BDS:NEAR,SETDRIVE:NEAR
+
+	if test
+	  IFNDEF NUMBUF 						  ;3.30
+	    EXTRN   MSGNUM:NEAR,MSGOUT:NEAR,dumpbytes:near,hex_to_ascii:near ;3.30
+	    EXTRN   outchar:near					  ;3.30
+	  ENDIF 							  ;3.30
+	endif
+
+SYSINITSEG SEGMENT PUBLIC 'SYSTEM_INIT'
+	ASSUME	CS:SYSINITSEG
+
+	EXTRN	CURRENT_DOS_LOCATION:WORD
+	EXTRN	FINAL_DOS_LOCATION:WORD
+	EXTRN	DEVICE_LIST:DWORD
+	EXTRN	MEMORY_SIZE:WORD
+	EXTRN	DEFAULT_DRIVE:BYTE
+	EXTRN	BUFFERS:WORD
+	EXTRN	SYSINIT:FAR
+SYSINITSEG	ENDS
+
+	ASSUME	CS:CODE 						  ;3.30
+
+;
+; End of disk modules for configuration
+;
+	EXTRN	End96tpi:byte
+	EXTRN	EndTwoHard:byte
+	EXTRN	EndOneHard:byte
+	EXTRN	EndSwap:byte
+	EXTRN	EndFloppy:byte
+;
+; IBM fixed up AT ROM
+;
+	EXTRN	IBM_DISK_IO:FAR
+

SRC/BIOS/MSGROUP.INC

@@ -0,0 +1,46 @@
+EVBOUND = 1  ;THIS VALUE BEING 0 DOES NO BOUNDARY ALLIGNMENT, VALUE 1	  ;3.30
+	     ; ALIGNS TO EVEN						  ;3.30
+; : : : : : : : : : : : : : :						  ;3.30
+	IF EVBOUND	;;IF EVEN (WORD) ALLIGNMENT IS REQUESTED,	  ;3.30
+; : : : : : : : : : : : : : :						  ;3.30
+EVENB	MACRO								  ;3.30
+	  EVEN	;;ADJUST TO EVEN BOUNDARY				  ;3.30
+	ENDM								  ;3.30
+									  ;3.30
+ODD	MACRO								  ;3.30
+;;GENERATE BOUNDARY PADDING TO FORCE ODD OFFSET 			  ;3.30
+	IF (($-CODE) MOD 2) EQ 0					  ;3.30
+	  DB	?							  ;3.30
+	ENDIF								  ;3.30
+	ENDM								  ;3.30
+									  ;3.30
+CODE_SEGMENT MACRO							  ;3.30
+;;ALLIGN THE SEGMENT ON WORD BOUNDARY TO ALLOW FOR EVEN ALLIGNMENT OF DATA;3.30
+CODE	SEGMENT WORD PUBLIC 'CODE'                                        ;3.30 ;3.30
+	ENDM								  ;3.30
+									  ;3.30
+; : : : : : : : : : : : : : :						  ;3.30
+	ELSE	;;SINCE EVEN ALLIGNMENT IS NOT DESIRED, JUST USE BYTE ALLI;3.30 GNMENT
+; : : : : : : : : : : : : : :						  ;3.30
+									  ;3.30
+EVENB	MACRO								  ;3.30
+;;REQUEST FOR WORD ALLIGNMENT DOES NOTHING				  ;3.30
+	ENDM								  ;3.30
+									  ;3.30
+ODD	MACRO								  ;3.30
+;;REQUEST FOR ODD ALLIGNMENT DOES NOTHING				  ;3.30
+	ENDM								  ;3.30
+									  ;3.30
+CODE_SEGMENT MACRO							  ;3.30
+;;SEGMENT IS ALLIGNED ON BYTE BOUNDARY FOR MINIMUM SIZE OF GENERATION	  ;3.30
+CODE	SEGMENT BYTE PUBLIC 'CODE'                                        ;3.30
+	ENDM								  ;3.30
+									  ;3.30
+; : : : : : : : : : : : : : :						  ;3.30
+	ENDIF								  ;3.30
+; : : : : : : : : : : : : : :						  ;3.30
+									  ;3.30
+	CODE_SEGMENT							  ;3.30
+	ASSUME	CS:CODE 						  ;3.30
+									  ;3.30
+

SRC/BIOS/MSHARD.ASM

@@ -0,0 +1,418 @@
+;***
+;	Title:	Disk
+;	By:	Michael Hanson
+;	C:	Copyright (C) 1985-1987 by Microsoft corp.
+;	Date:	1/11/85
+;
+;		There is a bug in some versions of IBM's AT ROM BIOS
+;		interupts are not disabled during read operations.
+;
+;	Use:	This program should be chained in line with the disk
+;		interupt 13h, it intercepts read calls to the hard disk
+;		and handles them appropriately.  For other functions it
+;		passes controll to OLD13, which should contain the
+;		address of the AT ROM disk routine. The entry point for
+;		this program is IBM_DISK_IO.
+;
+
+
+	.286c		;Use 80286 non-protected mode
+
+BIOSEG		= 040h		;Segment for ROM BIOS Data
+ROMSEG		= 0F000h	;Segment of ROM
+
+
+BAD_DISK 	= 01
+
+HF_PORT 	= 01F0h
+HF_REG_PORT 	= 03F6h
+
+;*	Offsets into Fixed disk parameter table
+FDP_PRECOMP	= 5
+FDP_CONTROL 	= 8
+
+DATA	SEGMENT AT BIOSEG	;ROM BIOS data segment
+
+	ORG 42h
+CMD_BLOCK	DB 6 DUP (?)
+
+;*	Offsets into CMD_BLOCK for registers
+PRE_COMP = 0	;Write Pre-compensation
+SEC_CNT	 = 1	;Sector count
+SEC_NUM	 = 2	;Sector number
+CYL_LOW	 = 3	;Cylinder number, low part
+CYL_HIGH = 4	;Cylinder number, high part
+DRV_HEAD = 5	;Drive/Head (Bit 7 = ECC mode, Bit 5 = 512 byte sectors, 
+		;            Bit 4 = drive number, Bits 3-0 have head number)
+CMD_REG  = 6	;Command register
+
+
+	ORG 074h
+
+DISK_STATUS1 	DB ?
+HF_NUM		DB ?
+CONTROL_BYTE	DB ?
+
+DATA	ENDS
+
+
+
+;***	Define where the ROM routines are actually located
+ROM	SEGMENT AT ROMSEG
+
+	ORG 02E1Eh
+ROMCOMMAND PROC FAR
+ROMCOMMAND ENDP
+
+	ORG 02E7Fh
+ROMWAIT	PROC FAR
+ROMWAIT	ENDP
+
+	ORG 02EE2h
+ROMWAIT_DRQ PROC FAR
+ROMWAIT_DRQ ENDP
+
+	ORG 02EF8h
+ROMCHECK_STATUS PROC FAR
+ROMCHECK_STATUS ENDP
+
+	ORG 02F69h
+ROMCHECK_DMA PROC FAR
+ROMCHECK_DMA ENDP
+
+	ORG 02F8Eh
+ROMGET_VEC PROC FAR
+ROMGET_VEC ENDP
+
+	ORG 0FF65h
+ROMFRET PROC FAR	;Far return at F000:FF65 in AT ROM.
+ROMFRET ENDP
+
+ROM	ENDS
+
+
+CODE	SEGMENT BYTE PUBLIC 'code'
+
+EXTRN	OLD13:DWORD		;Link to AT bios int 13h
+
+PUBLIC	IBM_DISK_IO	
+
+
+	ASSUME CS:CODE
+	ASSUME DS:DATA
+
+
+;***	IBM_DISK_IO - main routine, fixes AT ROM bug
+;
+;	ENTRY:	(AH) = function, 02 or 0A for read.
+;		(DL) = drive number (80h or 81h).
+;		(DH) = head number.
+;		(CH) = cylinder number.
+;		(CL) = Sector number (high 2 bits has cylinder number).
+;		(AL) = number of sectors.
+;		(ES:BX) = address of read buffer.
+;		For more on register contents see ROM BIOS listing.
+;		Stack set up for return by an IRET.
+;
+;	EXIT:	(AH) = status of current operation.
+;		(CY) = 1 IF failed, 0 if successful.
+;		For other register contents see ROM BIOS listing.
+;
+;	USES:	
+;
+;
+;	WARNING: Uses OLD13 vector for non-read calls.
+;		Does direct calls to the AT ROM.
+;		Does segment arithmatic.
+;
+;	EFFECTS: Performs DISK I/O operation.
+;
+IBM_DISK_IO PROC FAR
+	CMP DL, 80h
+	JB  ATD1		;Pass through floppy disk calls.
+	CMP AH, 02
+	JE  ATD2		;Intercept call 02 (read sectors).
+	CMP AH, 0Ah
+	JE  ATD2		;and call 0Ah (read long).
+ATD1:
+	JMP OLD13		;Use ROM INT 13h handler.
+ATD2:
+	PUSH BX
+	PUSH CX
+	PUSH DX
+	PUSH DI
+	PUSH DS
+	PUSH ES
+	PUSH AX
+	MOV  AX,BIOSEG		;Establish BIOS segment addressing.
+	MOV  DS,AX
+	MOV  DISK_STATUS1, 0	;Initially no error code.
+	AND  DL, 07fh		;Mask to hard disk number
+	CMP  DL, HF_NUM
+	JB   ATD3		;Disk number in range
+	MOV  DISK_STATUS1, BAD_DISK
+	JMP  SHORT ATD4		;Disk number out of range error, return
+
+ATD3:
+	PUSH BX
+	MOV  AX, ES		;Make ES:BX to Seg:000x form.
+	SHR  BX, 4
+	ADD  AX, BX
+	MOV  ES, AX
+	POP  BX
+	AND  BX,000Fh
+	PUSH CS
+	CALL CHECK_DMA
+	JC   ATD4		;Abort if DMA across segment boundary
+
+	POP  AX			;Restore AX register for SETCMD
+	PUSH AX
+	CALL SETCMD		;Set up command block for disk op
+	MOV  DX, HF_REG_PORT
+	OUT  DX, AL		;Write out command modifier
+	CALL DOCMD		;Carry out command
+ATD4:
+	POP  AX
+	MOV  AH,DISK_STATUS1	;On return AH has error code
+	STC
+	OR   AH,AH
+	JNZ  ATD5 		;Carry set if error
+	CLC
+ATD5:
+	POP  ES
+	POP  DS
+	POP  DI
+	POP  DX
+	POP  CX
+	POP  BX
+	RET  2			;Far return, dropping flags
+IBM_DISK_IO ENDP
+
+
+
+;***	SETCMD - Set up CMD_BLOCK for the disk operation
+;
+;	ENTRY:	(DS) = BIOS Data segment.
+;		(ES:BX) in seg:000x form.
+;		Other registers as in INT 13h call
+;	
+;	EXIT:	CMD_BLOCK set up for disk read call.
+;		CONTROL_BYTE set up for disk operation.
+;		(AL) = Control byte modifier
+;
+;
+;	Sets the fields of CMD_BLOCK using the register contents
+;	and the contents of the disk parameter block for the given drive.
+;
+;	WARNING: (AX) destroyed.
+;		Does direct calls to the AT ROM.
+;
+SETCMD	PROC NEAR
+	MOV  CMD_BLOCK[SEC_CNT], AL
+	MOV  CMD_BLOCK[CMD_REG], 020h	;Assume function 02
+	CMP  AH, 2
+	JE   SETC1			;CMD_REG = 20h if function 02 (read)
+	MOV  CMD_BLOCK[CMD_REG], 022h   ;CMD_REG = 22h if function 0A (" long)
+SETC1:					;No longer need value in AX
+	MOV  AL, CL
+	AND  AL, 03fh			;Mask to sector number
+	MOV  CMD_BLOCK[SEC_NUM], AL
+	MOV  CMD_BLOCK[CYL_LOW], CH
+	MOV  AL, CL
+	SHR  AL, 6			;Get two high bits of cylender number
+	MOV  CMD_BLOCK[CYL_HIGH], AL
+	MOV  AX, DX
+	SHL  AL, 4			;Drive number
+	AND  AH, 0Fh
+	OR   AL, AH			;Head number
+	OR   AL, 0A0h			;Set ECC and 512 bytes per sector
+	MOV  CMD_BLOCK[DRV_HEAD], AL
+	PUSH ES				;GET_VEC destroys ES:BX
+	PUSH BX
+	PUSH CS
+	CALL GET_VEC
+	MOV  AX, ES:FDP_PRECOMP[BX]	;Write pre-comp from disk parameters
+	SHR  AX, 2
+	MOV  CMD_BLOCK[PRE_COMP],AL	;Only use low part
+	MOV  AL, ES:FDP_CONTROL[BX]	;Control byte modifier
+	POP  BX
+	POP  ES
+	MOV  AH, CONTROL_BYTE
+	AND  AH, 0C0h			;Keep disable retry bits
+	OR   AH, AL
+	MOV  CONTROL_BYTE, AH
+	RET
+SETCMD	ENDP	
+
+
+
+;***	DOCMD - Carry out READ operation to AT hard disk
+;
+;	ENTRY:	(ES:BX) = address for read in data.
+;		CMD_BLOCK set up for disk read.
+;
+;	EXIT:	Buffer at (ES:BX) contains data read.
+;		DISK_STATUS1 set to error code (0 if success).
+;
+;	
+;
+;	WARNING: (AX), (BL), (CX), (DX), (DI) destroyed.
+;		No check is made for DMA boundary overrun.
+;
+;	EFFECTS: Programs disk controller.
+;		Performs disk input.
+;
+DOCMD	PROC NEAR
+	MOV  DI, BX		;(ES:DI) = data buffer addr.
+	PUSH CS
+	CALL COMMAND
+	JNZ  DOC3
+DOC1:
+	PUSH CS
+	CALL WAIT		;Wait for controller to complete read
+	JNZ  DOC3
+	MOV  CX, 100h		;256 words per sector
+	MOV  DX, HF_PORT
+	CLD			;String op goes up
+	CLI			;Disable interrupts (BUG WAS FORGETTING THIS)
+  REPZ  INSW			;Read in sector
+  	STI
+	TEST CMD_BLOCK[CMD_REG], 02
+	JZ   DOC2		;No ECC bytes to read.
+	PUSH CS
+	CALL WAIT_DRQ
+	JC   DOC3
+	MOV  CX, 4		;4 bytes of ECC
+	MOV  DX, HF_PORT
+	CLI
+  REPZ  INSB			;Read in ECC
+  	STI
+DOC2:
+	PUSH CS
+	CALL CHECK_STATUS
+	JNZ  DOC3		;Operation failed
+	DEC  CMD_BLOCK[SEC_CNT]	
+	JNZ  DOC1		;Loop while more sectors to read
+DOC3:
+	RET
+DOCMD	ENDP
+
+
+
+;***	GET_VEC - Get pointer to hard disk parameters.
+;
+;	ENTRY:	(DL) = Low bit has hard disk number (0 or 1).
+;
+;	EXIT:	(ES:BX) = address of disk parameters table.
+;
+;	USES:	AX for segment computation.
+;
+;	Loads ES:BX from interrupt table in low memory, vector 46h (disk 0)
+;	or 70h (disk 1).
+;	
+;	WARNING: (AX) destroyed.
+;		This does a direct call to the AT ROM.
+;
+GET_VEC	PROC NEAR
+	PUSH OFFSET ROMFRET
+	JMP  ROMGET_VEC
+GET_VEC ENDP
+
+
+
+;***	COMMAND - Send contents of CMD_BLOCK to disk controller.
+;
+;	ENTRY:	Control_byte 
+;		CMD_BLOCK - set up with values for hard disk controller.
+;
+;	EXIT:	DISK_STATUS1 = Error code.
+;		NZ if error, ZR for no error.
+;
+;
+;	WARNING: (AX), (CX), (DX) destroyed.
+;		Does a direct call to the AT ROM.
+;
+;	EFFECTS: Programs disk controller.
+;
+COMMAND	PROC NEAR
+	PUSH OFFSET ROMFRET
+	JMP  ROMCOMMAND
+COMMAND ENDP
+
+
+
+;***	WAIT - Wait for disk interrupt
+;
+;	ENTRY:	Nothing.
+;
+;	EXIT:	DISK_STATUS1 = Error code.
+;		NZ if error, ZR if no error.
+;
+;
+;	WARNING: (AX), (BL), (CX) destroyed.
+;		Does a direct call to the AT ROM.
+;		
+;	EFFECTS: Calls int 15h, function 9000h.
+;
+WAIT	PROC NEAR
+	PUSH OFFSET ROMFRET 
+	JMP  ROMWAIT
+WAIT	ENDP
+
+
+
+;***	WAIT_DRQ - Wait for data request.
+;
+;	ENTRY:	Nothing.
+;
+;	EXIT:	DISK_STATUS1 = Error code.
+;		CY if error, NC if no error.
+;
+;
+;	WARNING: (AL), (CX), (DX) destroyed.
+;		Does a direct call to the AT ROM.
+;
+WAIT_DRQ PROC NEAR
+	PUSH OFFSET ROMFRET
+	JMP  ROMWAIT_DRQ
+WAIT_DRQ ENDP
+
+
+
+;***	CHECK_STATUS - Check hard disk status.
+;
+;	ENTRY:	Nothing.
+;
+;	EXIT:	DISK_STATUS1 = Error code.
+;		NZ if error, ZR if no error.
+;
+;
+;	WARNING: (AX), (CX), (DX) destroyed.
+;		Does a direct call to the AT ROM.
+;
+CHECK_STATUS PROC NEAR
+	PUSH OFFSET ROMFRET
+	JMP  ROMCHECK_STATUS
+CHECK_STATUS ENDP
+
+
+
+;***	CHECK_DMA - check for DMA overrun 64k segment.
+;
+;	ENTRY:	(ES:BX) = addr. of memory buffer in seg:000x form.
+;		CMD_BLOCK set up for operation.
+;
+;	EXIT:	DISK_STATUS1 - Error code.
+;		CY if error, NC if no error.
+;
+;
+;	WARNING: Does a direct call to the AT ROM.
+;
+CHECK_DMA PROC NEAR
+	PUSH OFFSET ROMFRET
+	JMP  ROMCHECK_DMA
+CHECK_DMA ENDP
+
+
+CODE	ENDS
+	END

SRC/BIOS/MSLOAD.ASM

@@ -0,0 +1,767 @@
+title	Non-Contiguous BIOS Loader (MSLOAD)				  
+									  
+IF1									  
+	%OUT ASSEMBLING: Non-Contiguous BIOS Loader (MSLOAD)		  
+	%OUT								  
+ENDIF									  
+									  
+bootseg 	segment at 0h						  
+       org	7C00h							  
+Boot_Sector		label	byte					  
+	org	7D00h							  
+Relocate_Start		label	byte					  
+bootseg 	ends							  
+									  
+									  
+dosseg	       segment at 70h						  
+       org	00h							  
+BIOS_Address	    label   byte					  
+									  
+dosseg	       ends							  
+									  
+									  
+cseg		segment public para 'code'                                
+		assume	cs:cseg,ds:cseg,es:cseg,ss:cseg 		  
+									  
+									  
+									  
+include msload.inc							  
+									  
+org	0h								  
+									  
+start:									  
+									  
+subttl	Setup Stack							  
+page									  
+;***********************************************************************  
+;  Setup_Stack								  
+;***********************************************************************  
+;									  
+; Input:     none							  
+;									  
+; Output:								  
+;									  
+;   SS:SP =  0:7C00h							  
+;   AX destroyed							  
+;-----------------------------------------------------------------------  
+; First thing is to reset the stack to a better and more known place.	  
+;									  
+; Move the stack to just under the boot record and relocation area (0:7C00h)
+;									  
+; Preserve all other registers						  
+;----------------------------------------------------------------------   
+									  
+	CLI				;Stop interrupts till stack ok	  
+	XOR	AX,AX							  
+	MOV	SS,AX			;Work in stack just below this routine
+	MOV	SP,7C00h - 30		;Leave room for stack frame	  
+	MOV	BP,7C00h - 30		;Point BP as stack index pointer  
+	STI								  
+									  
+									  
+subttl	Save Input Values						  
+page									  
+;***********************************************************************  
+;  Save_Input_Values							  
+;***********************************************************************  
+;									  
+; Input:     none							  
+;									  
+;   DL = INT 13 drive number we booted from				  
+;   CH = media byte							  
+;   BX = First data sector on disk (0-based)				  
+;									  
+; Output:								  
+;									  
+;   BX = first data sector on disk					  
+;   CL = number of floppies including fake one				  
+;   CH = media byte							  
+;									  
+;   [bp].Media_Byte = input CH						  
+;   [bp].Drive_Number = input DL					  
+;   [bp].First_Sector = input BX					  
+;   [bp].Drive_Boot = output AX 					  
+;   [bp].Number_Floppy = output CL					  
+;   [bp].Number_Sectors = Sectors/track 				  
+;   [bp].Number_Heads = heads/cylinder					  
+;									  
+;   DS = 0								  
+;   AX,DX,SI destroyed							  
+;									  
+; Calls:     none							  
+;-----------------------------------------------------------------------  
+; Save input information						  
+;									  
+; Get Equipment Flag							  
+;									  
+; Find how many drives on system					  
+;									  
+; Figure out boot drive 						  
+;									  
+;----------------------------------------------------------------------   
+Save_Input_Values:							  
+	mov	[bp].First_Sector,bx					  
+	mov	[bp].media_Byte,ch					  
+	mov	[bp].Drive_Number,dl					  
+;	INT	11h			;GET EQUIPMENT STATUS		  
+;	ROL	AL,1			;Put bits 6 & 7 into bits 0 & 1   
+;	ROL	AL,1							  
+;	AND	AX,3			;Only look at bits 0 & 1	  
+;	JNZ	NOTsingle		;Zero means single drive system   
+;	INC	AX			;Pretend it's a two drive system  
+NOTSingle:								  
+;	INC	AX			;AX has number of drives, 2-4	  
+					;Is also 0 indexed boot drive if we
+					;  booted off hard file 	  
+;	MOV	CL,AL			;CH is FAT ID, CL # floppies	  
+;	TEST	DL,80H			;BOOT FROM FLOPPY ?		  
+;	JNZ	GOTHRD			;NO.				  
+;	XOR	AX,AX			;INDICATE BOOT FROM DRIVE A	  
+GotHrd: 								  
+	xor	ax,ax				;Segment 0		  
+	mov	ds,ax							  
+									  
+	assume	ds:Bootseg						  
+									  
+	mov	ax,Boot_Sector.SECLIM		;Get Sectors per track	  
+	mov	[bp].Sectors_Per_Track,ax				  
+	mov	ax,Boot_Sector.HDLIM		;Get BPB heads per cylinder
+	mov	[bp].Number_Of_Heads,ax 				  
+	mov	ax,Boot_Sector.cSecFat		;Get sectors per FAT	  
+	mov	[bp].Number_Of_FAT_Sectors,ax				  
+	mov	ax,Boot_Sector.cSecHid		;Get hidden sectors	  
+	mov	[bp].Hidden_Sectors,ax					  
+	mov	ax,Boot_Sector.cSecRes		;Get Reserved Sectors	  
+	mov	[bp].Reserved_Sectors,ax				  
+									  
+									  
+subttl	Find_Cluster_Size						  
+page									  
+;***********************************************************************  
+;  Find_Cluster_Size							  
+;***********************************************************************  
+;									  
+; Input:     BPB information in loaded boot record at 0:7C00h		  
+;									  
+; Output:								  
+;									  
+;	DS = 0								  
+;	AX = Bytes/Cluster						  
+;	BX = Sectors/Cluster						  
+;	SI destroyed							  
+; Calls:     none							  
+;-----------------------------------------------------------------------  
+;									  
+; Get Bytes/sector from BPB						  
+;									  
+; Get sectors/cluster from BPB						  
+;									  
+; Bytes/cluster = Bytes/sector * sector/cluster 			  
+;----------------------------------------------------------------------   
+Find_Cluster_Size:							  
+									  
+;For the time being just assume the boot record is valid and the BPB	  
+;is there.								  
+									  
+	xor	ax,ax				;Segment 0		  
+	mov	ds,ax							  
+									  
+	assume ds:bootseg						  
+									  
+	mov	ax,Boot_Sector.ByteSec		;Get BPB bytes/sector	  
+	xor	bx,bx							  
+	mov	bl,Boot_Sector.cAlloc		;Get sectors/cluster	  
+	mul	bx				;Bytes/cluster		  
+	mov	[bp].Size_Cluster,ax		  ;Save it		  
+									  
+									  
+									  
+subttl	Determine FAT size						  
+page									  
+;***********************************************************************  
+;  Determine_FAT_Size							  
+;***********************************************************************  
+;									  
+; Notes:								  
+;									  
+;   Determine if FAT is 12 or 16 bit FAT. 12 bit FAT if floppy, read MBR  
+;   to find out what system id byte is. 				  
+;									  
+; Input:     [bp].Media_Byte = FAT ID Byte				  
+;									  
+; Output:								  
+;									  
+;   [BP].Fat_Size = FAT12_bit or FAT16_bit				  
+;   ES = 0								  
+;   All other registers destroyed					  
+;									  
+; Calls: READ_DISK							  
+;-----------------------------------------------------------------------  
+;IF (not FAT ID of F8)							  
+;    {12 bit FAT}							  
+;ELSE									  
+;   {									  
+;     Read in master boot record at 0:7C00h				  
+;									  
+;     Scan system id bytes for 1 or 4					  
+;									  
+;     IF (Sys id = 4)							  
+;	 {16 bit FAT}							  
+;     ELSE								  
+;	 {IF (Sys id = 1)						  
+;	     {12 bit FAT}						  
+;	  ELSE								  
+;	     {Error}							  
+;	  ENDIF 							  
+;     ENDIF								  
+; ENDIF 								  
+;									  
+;----------------------------------------------------------------------   
+Determine_FAT_Size:							  
+	mov	[bp].FAT_Size,FAT12_bit 	      ;Assume 12 bit fat  
+	cmp	[bp].Media_Byte,0F8h		  ;Is it floppy 	  
+	jne	FAT_Size_Found			;Yep, all set		  
+	mov	[bp].Logical_Sector,0		  ;Got hardfile, go get MBR
+	xor	ax,ax							  
+	mov	es,ax							  
+	mov	di,offset Relocate_Start				  
+	mov	[bp].Sector_Count,1					  
+	call	Disk_Read						  
+	mov	si,offset Relocate_Start+1C2h				  
+	mov	cx,4							  
+	xor	ax,ax							  
+	mov	ds,ax							  
+Find_Sys_Id:								  
+	mov	[bp].FAT_Size,FAT12_bit 	      ;Assume 12 bit fat  
+	cmp	byte ptr [si],1 					  
+	je	FAT_Size_Found						  
+	mov	[bp].FAT_Size,FAT16_bit 	      ;Assume 12 bit fat  
+	cmp	byte ptr [si],4 					  
+	je	Fat_Size_Found						  
+	add	si,16							  
+	loop	Find_Sys_Id						  
+       ;xxxxxxxxxxxxxxxxxxxxxxxxxx error				  
+FAT_Size_Found: 							  
+									  
+									  
+subttl Determine First Cluster						  
+page									  
+;***********************************************************************  
+;  Determine_First_Cluster						  
+;***********************************************************************  
+;									  
+; Notes: Find the last cluster that was loaded				  
+;									  
+;									  
+; Input:								  
+;									  
+;   [BP].Size_Cluster							  
+;   Total_Length is offset of end of MSLOAD				  
+;									  
+; Output:								  
+;									  
+;   [BP].Last_Found_Cluster = the last cluster loaded containing MSLOAD   
+;			      code. This is also the number of clusters   
+;			      with MSLOAD code +2			  
+;									  
+; Calls:     none							  
+;-----------------------------------------------------------------------  
+;									  
+;Get length of loader portion of bios					  
+;									  
+;Divide by bytes/cluster						  
+;									  
+;If (Remainder = 0)							  
+;   {Last_Used_Cluster = quotient+2}					  
+;Else									  
+;   {Last_Used_Cluster = quotient+3}					  
+;----------------------------------------------------------------------   
+Determine_First_Cluster:						  
+	mov	[bp].Last_Found_Cluster,1	;2 is the first cluster-1 
+	mov	ax,offset Total_Length		;Get whole length	  
+	xor	dx,dx							  
+	div	[bp].Size_Cluster		;Div by bytes/sector	  
+	add	[bp].Last_Found_Cluster,ax	;Save the result	  
+	cmp	dx,0				;Was there remainder?	  
+	je	First_Cluster_Found		;No			  
+	inc	[bp].Last_Found_Cluster 	;Yes, round up		  
+									  
+First_Cluster_Found:							  
+									  
+									  
+subttl	Relocate							  
+page									  
+;									  
+;***********************************************************************  
+;  RELOCATE								  
+;***********************************************************************  
+;									  
+; Notes:								  
+;									  
+;   Relocate the loader code to 0:7C00 - this will allow bios to be loaded
+;   underneath at 70:0							  
+;									  
+; Input:     none							  
+;									  
+; Output:    es is set to 0						  
+;	     ds is set to cs (70h)					  
+;	     ax,cx,si,di destroyed					  
+;									  
+; Calls:     none							  
+;-----------------------------------------------------------------------  
+; Copy code from Relocate_Code to Relocate_Start (7C00h)		  
+;									  
+; The length to copy is Relocate_Length 				  
+;									  
+; Jump to relocated code						  
+;-----------------------------------------------------------------------  
+;									  
+Relocate:								  
+	push	cs				;Set up ds segreg	  
+	pop	ds							  
+	xor	ax,ax				;Set up ES segreg	  
+	mov	es,ax							  
+									  
+	assume	es:bootseg,ds:cseg					  
+									  
+	mov	si,offset Relocate_Code 	;Source 		  
+	mov	di,offset Relocate_Start	;Target 		  
+	mov	cx,Relocate_Length		;Length 		  
+	rep	movsb				;Go do it		  
+									  
+	jmp	far ptr Relocate_Start					  
+									  
+;									  
+;*************************************************************************
+;* RELOCATED CODE ********************************************************
+;*************************************************************************
+;									  
+									  
+Relocate_Code	label	byte						  
+									  
+subttl	Read In FAT							  
+page									  
+;***********************************************************************  
+;  Read_In_FAT								  
+;***********************************************************************  
+;									  
+; Notes:								  
+;									  
+;   Reads in the entire FAT at 0:8000. This gives the relocated portion   
+;   of this loader a maximum size of 1024 bytes (8000 - 7C00). The max	  
+;   size of the FAT is 64 sectors (32k) so everything will fit under the  
+;   64k DMA boundary, so no problems with loading.			  
+;									  
+; Input:     none							  
+;									  
+; Output:								  
+;									  
+;   ES = 0								  
+;   All sectors destroyed						  
+;									  
+; Calls:  READ DISK							  
+;-----------------------------------------------------------------------  
+; Get number of sectors in FAT						  
+;									  
+; Set ES:DI to 0:8000h							  
+;									  
+; Read in the sectors							  
+;									  
+;----------------------------------------------------------------------   
+Read_In_FAT:								  
+	xor	ax,ax							  
+	mov	ds,ax							  
+									  
+	assume	ds:bootseg						  
+									  
+	mov	ax,[bp].Number_Of_FAT_Sectors	;Get sectors/FAT	  
+	mov	[bp].Sector_Count,ax		;Number of sectors to read
+	mov	ax,[bp].Hidden_Sectors		;Hidden+Reserved = Fat	  
+	add	ax,[bp].Reserved_Sectors				  
+	mov	[bp].Logical_Sector,ax		;Save it, setup for read  
+	xor	ax,ax							  
+	mov	es,ax							  
+	mov	di,8000h			;Point to buffer	  
+	call	Disk_Read						  
+									  
+subttl	Keep Loaded BIO 						  
+page									  
+;***********************************************************************  
+;  KEEP LOADED BIO							  
+;***********************************************************************  
+;									  
+; Notes:								  
+;									  
+;   Determine how much of bios was loaded in when the loader was loaded   
+;   by the boot record (only the portion that is guaranteed to be	  
+;   contiguous								  
+;									  
+; Input:								  
+;									  
+;   [BP].Last_Found_Cluster = number of clusters used for loader+2	  
+;									  
+; Output:								  
+;	ES = DS = 70h							  
+;	DI = Next offset to load bios code				  
+;	AX,BX,CX,DX,SI destroyed					  
+;									  
+;	[bp].Next_BIO_Location = DI on output				  
+;	[bp].Last_Cluster = last cluster loaded 			  
+;									  
+; Calls:     none							  
+;-----------------------------------------------------------------------  
+;Number of clusters loaded+2 is in [BP].Last_Found_Cluster		  
+;									  
+;Multiply cluster * cluster size in bytes to get total loaded for MSLOAD  
+;									  
+;Subtract TOTAL_LOADED - LOADBIO_SIZE to get loaded bios in last cluster  
+;									  
+;Relocate this piece of bios down to 70:0				  
+;									  
+;----------------------------------------------------------------------   
+Keep_Loaded_BIO:							  
+	push	ds							  
+	mov	ax,[bp].Last_Found_Cluster	;Point to last cluster loaded  
+	sub	ax,1				;Get number of clusters loaded 
+	mul	[bp].Size_Cluster		;Get total bytes loaded by
+						;This is always < 64k, so 
+						;lower 16 bits ok	  
+	sub	ax,LoadBio_Size 		;Get portion of bios loaded
+	mov	cx,ax				;Save length to move	  
+	mov	ax,70h				;Segment at 70h 	  
+	mov	ds,ax							  
+	mov	es,ax							  
+	mov	si,offset cs:Total_Length	;Point at bios		  
+	mov	di,0				;Point at 70:0		  
+	rep	movsb				;Relocate this code	  
+	mov	[bp].Next_Bio_Location,di	  ;Save where to load next
+	pop	ds							  
+									  
+subttl Get Contiguous Clusters						  
+page									  
+;***********************************************************************  
+;  Get_Contiguous_Clusters						  
+;***********************************************************************  
+;									  
+; Notes: Go find clusters as long as they are contiguous		  
+;									  
+;									  
+; Input:								  
+;									  
+;   [BP].Next_BIO_Location						  
+;   [BP].								  
+;									  
+;									  
+; Output:								  
+;									  
+;									  
+; Calls: Get_Next_FAT_Entry						  
+;-----------------------------------------------------------------------  
+;									  
+;Set [BP].Sector_Count to Sectors per cluster				  
+;									  
+;Call Get_Next_FAT_Entry to get next cluster in file			  
+;									  
+;Call Check_for_EOF							  
+;									  
+;IF (NC returned)							  
+;									  
+;   {Call Get_Next_FAT_Entry						  
+;									  
+;    IF (New cluster is contig to old cluster)				  
+;	{Add sectors per cluster to [BP].Sector_Count			  
+;									  
+;	 Call Check_For_EOF						  
+;									  
+;	 IF (NC returned)						  
+;									  
+;									  
+;----------------------------------------------------------------------   
+Get_Contiguous_Cluster: 						  
+	xor	ah,ah							  
+	mov	al,Boot_Sector.cAlloc	;Assume we will get one cluster   
+	mov	[bp].Sector_Count,ax					  
+	call	Get_Next_Fat_Entry	;Go get it			  
+	mov	[bp].Last_Found_Cluster,ax ;Update the last one found	  
+	cmp	[bp].EOF,End_Of_File					  
+	je	GOTO_bios						  
+									  
+Got_Contig_Clusters:							  
+	sub	ax,2			;Zero base the cluster		  
+	xor	ch,ch							  
+	mov	cl,Boot_Sector.cAlloc	;Get sectors per cluster	  
+	mul	cx			;Get how many			  
+	add	ax,[bp].First_Sector	;See where the data sector starts 
+	mov	[bp].Logical_Sector,ax	;Save it			  
+	mov	di,[bp].Next_Bio_Location ;Get where to put code	  
+	push	[bp].Sector_Count	;Save how many sectors		  
+	mov	ax,dosseg		;Get area to load code		  
+	mov	es,ax							  
+	call	Disk_Read						  
+	pop	ax			;Get back total sectors read in   
+;	jc	##########						  
+	mul	Boot_Sector.ByteSec	  ;Get number of bytes we loaded  
+	add	[bp].Next_Bio_Location,ax ;Point to where to load next	  
+	jmp	short Get_Contiguous_Cluster				  
+									  
+subttl	GOTO bios							  
+page									  
+;***********************************************************************  
+;  GOTO_bios								  
+;***********************************************************************  
+;									  
+; Notes:								  
+;									  
+;  Set up required registers for bios, then jump to it (70:0)		  
+;									  
+; Input:     none							  
+;									  
+;   [bp].Media_Byte = media byte					  
+;   [bp].Drive_Number = INT 13 drive number we booted from		  
+;   [bp].First_Sector = First data sector on disk (0-based)		  
+;									  
+; Output:								  
+;									  
+;   Required by MSINIT							  
+;   DL = INT 13 drive number we booted from				  
+;   CH = media byte							  
+;   BX = First data sector on disk (0-based)				  
+;									  
+; Calls:     none							  
+;-----------------------------------------------------------------------  
+;									  
+; Set up registers for MSINIT then do Far Jmp				  
+;									  
+;----------------------------------------------------------------------   
+GOTO_bios:								  
+	mov	ch,[bp].Media_Byte	  ;Restore regs required for MSINT
+	mov	dl,[bp].Drive_Number					  
+	mov	bx,[bp].First_Sector					  
+	jmp	far ptr bios_Address					  
+									  
+									  
+									  
+									  
+subttl	Disk Read							  
+page									  
+;***********************************************************************  
+; Disk_Read								  
+;***********************************************************************  
+;									  
+; Notes:								  
+;									  
+;  Read in the [BP].Sector_Count number of sectors at ES:DI		  
+;									  
+;									  
+; Input:     none							  
+;									  
+;   DI = Offset of start of read					  
+;   ES = Segment of read						  
+;   [bp].Sector_Count = number of sectors to read			  
+;   [bp].Logical_sector = starting sector				  
+;   Following is BPB info that must be setup prior to call		  
+;   [bp].Number_Of_Heads						  
+;   [bp].Number_Of_Sectors						  
+;   [bp].Drive_Number							  
+;   [bp].Sectors_Per_Track						  
+;									  
+; Output:								  
+;									  
+;   ES = 0								  
+;   AX,BX,CX,DX,SI,DI destroyed 					  
+;									  
+;									  
+; Calls:     none							  
+;-----------------------------------------------------------------------  
+; Divide start sector by sectors per track				  
+; The remainder is the actual sector number, 0 based			  
+;									  
+; Increment actual sector number to get 1 based 			  
+;									  
+; The quotient is the number of tracks - divide by heads to get the cyl   
+;									  
+; The remainder is actual head, the quotient is cylinder		  
+;									  
+; Figure the number of sectors in that track, set AL to this		  
+;									  
+; Do the read								  
+;									  
+; If Error, Do RESET, then redo the INT 13h				  
+;									  
+; If successful read, Subtract # sectors read from Sector_Count, Add to   
+; Logical Sector, add #sectors read * Sector_Size to BX;		  
+;									  
+; If Sector_Count <> 0 Do next read					  
+;----------------------------------------------------------------------   
+Disk_Read:								  
+									  
+;									  
+; convert a logical sector into Track/sector/head.  AX has the logical	  
+; sector number 							  
+;									  
+DODIV:									  
+	MOV	cx,5			;5 retries			  
+									  
+Try_Read:								  
+       PUSH    cx		       ;Save it 			  
+									  
+       MOV     AX,[bp].Logical_Sector	 ;Get starting sector		  
+       XOR     DX,DX							  
+       DIV     word ptr [bp].Sectors_Per_Track				  
+       MOV     bx,[bp].Sectors_Per_Track ;Get number of sectors we can	  
+       sub     bx,dx		       ;read in this track		  
+       mov     si,bx							  
+       cmp     [bp].Sector_Count,si    ;Is possible sectors in track more 
+       jae     Got_Length	       ;than what we need to read?	  
+       mov     si,[bp].Sector_Count    ;Yes, only read what we need to	  
+									  
+Got_Length:								  
+       INC     DL		       ; sector numbers are 1-based	  
+       MOV     bl,dl		       ;Start sector in DL		  
+       XOR     DX,DX							  
+       DIV     word ptr [bp].Number_Of_Heads  ;Start cyl in ax,head in DL 
+       MOV     DH,DL							  
+;									  
+; Issue one read request.  ES:BX have the transfer address, AL is the number
+; of sectors.								  
+;									  
+;								      
+;  Now convert to standard ROM call				      
+;								      
+	mov	cl,bl			;Get starting sector	      
+	ror	ah,1			;Set up high 2 bits	      
+	ror	ah,1			;Set up high 2 bits	      
+	or	cl,ah			;Combine cyl/start sector     
+	mov	ch,al			;Set low order of cyl	      
+	mov	bx,di			;Set offset		      
+	mov	dl,[bp].Drive_Number	;Set drive		      
+	mov	ax,si			;Set count		      
+	mov	ah,02			;Read Command		      
+	push	ax			;Save regs		      
+	push	di			; *			      
+	int	13h			;Call ROM-Bios		      
+	pop	di			;Restore Regs		      
+	pop	ax			; *			      
+	pop	cx			;Get retry count back		  
+	jnc	Read_OK 						  
+	push	cx							  
+	mov	bx,di			;
+	push	di			;Save Reg		      
+	mov	dl,[bp].Drive_Number	;Set drive		      
+	mov	ah,0			;RESET Disk Command	      
+	int	13h			;Call ROM-Bios		      
+	pop	di			;Restore Reg		      
+	pop	cx							  
+	loop	Try_Read						  
+       ;xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx error				  
+Read_OK:								  
+	xor	ah,ah			;Mask out command, just get # read
+	sub	[bp].Sector_Count,ax	  ;Bump number down		  
+	jz	Read_Finished						  
+	add	[bp].Logical_Sector,ax	  ;Where to start next time	  
+	xor	bx,bx			  ;Get number sectors read	  
+	mov	bl,al							  
+	mov	ax,Boot_Sector.ByteSec	  ;Bytes per sector		  
+	mul	bx			  ;Get total bytes read 	  
+	add	di,ax			  ;Add it to offset		  
+	jmp	short DODIV						  
+Read_Finished:								  
+	RET								  
+									  
+subttl	GET NEXT FAT ENTRY						  
+page									  
+;***********************************************************************  
+;  GET_NEXT_FAT_ENTRY							  
+;***********************************************************************  
+;									  
+; Notes:								  
+;									  
+;   Given the last cluster found, this will return the next cluster of	  
+;   bios. If the last cluster is (F)FF8 - (F)FFF, then the final cluster  
+;   of bios has been loaded, and control is passed to GOTO_bios 	  
+;									  
+; Input:								  
+;									  
+;    [bp].Last_Found_Cluster						  
+;    [bp].Fat_Size							  
+;									  
+; Output:								  
+;									  
+;   [bp].Last_Found_Cluster (updated)					  
+;									  
+; Calls:  none								  
+;-----------------------------------------------------------------------  
+; Get Last_Found_Cluster						  
+;									  
+; IF (16 bit FAT)							  
+;    {IF (Last_Found_Cluster = FFF8 - FFFF)				  
+;	 {JMP GOTO_bios}						  
+;     ELSE								  
+;	{Get offset by multiply cluster by 2}				  
+;									  
+; ELSE									  
+;    {IF (Last_Found_Cluster = FF8 - FFF)				  
+;	 {JMP GOTO_bios}						  
+;     ELSE								  
+;	{Get offset by	- multiply cluster by 3 			  
+;									  
+;	 Rotate right to divide by 2					  
+;									  
+;	 IF (CY set - means odd number) 				  
+;	    {SHR 4 times to keep high twelve bits}			  
+;									  
+;	 ELSE								  
+;	    {AND with 0FFFh to keep low 12 bits}			  
+;	}								  
+;    }									  
+;									  
+; Add in 8000h to get offset of next cluster in FAT buffer		  
+;									  
+;----------------------------------------------------------------------   
+Get_Next_FAT_Entry:							  
+									  
+	mov	[bp].EOF,End_Of_File		;Assume last cluster	  
+	mov	ax,[bp].Last_Found_Cluster	;Get last cluster	  
+	cmp	[bp].Fat_Size,FAT12_bit 				  
+	jne	Got_16_Bit						  
+	xor	bx,bx							  
+	mov	bl,3				;Mult by 3		  
+	mul	bx							  
+	shr	ax,1				;Div by 2 to get 1.5	  
+	mov	si,ax				;Get the final buffer offset
+	mov	ax,[si]+8000h			;Get new cluster	  
+	test	[bp].Last_Found_Cluster,1	;Was last cluster odd?	  
+	jnz	Odd_Result			;If Carry set it was odd  
+	and	ax,0FFFh			;Keep low 12 bits	  
+	jmp	short Test_EOF						  
+									  
+Odd_Result:								  
+	 mov	cl,4				;Keep high 12 bits for odd
+	 shr	ax,cl							  
+Test_EOF:								  
+	 cmp	 ax,0FF8h			 ;Is it last cluster?	  
+	 jae	 Got_Cluster_Done		 ;Yep, all done here	  
+	 jmp	short Not_Last_CLuster					  
+									  
+Got_16_Bit:								  
+	shl	ax,1				;Multiply cluster by 2	  
+	mov	si,ax				;Get the final buffer offset
+	mov	ax,[si]+8000h			;Get new cluster	  
+	cmp	ax,0FFF8h						  
+	jae	Got_Cluster_Done					  
+									  
+Not_Last_Cluster:							  
+	mov	[bp].EOF,not End_Of_File	    ;Assume last cluster  
+									  
+Got_Cluster_Done:							  
+	ret								  
+									  
+									  
+									  
+									  
+Relocate_Length   equ  $ - Read_In_FAT					  
+Total_Length label byte 						  
+LoadBIO_Size	equ	$ - Start					  
+									  
+cseg	ends								  
+end	start								  

SRC/BIOS/MSLOAD.INC

@@ -0,0 +1,52 @@
+									  ;3.30
+Stack_Frame		STRUC						  ;3.30
+Number_Of_Heads 	dw	0					  ;3.30
+Size_Cluster		dw	0					  ;3.30
+Logical_Sector		dw	0					  ;3.30
+Sector_Count		dw	0					  ;3.30
+Number_Of_FAT_Sectors	dw	0					  ;3.30
+Hidden_Sectors		dw	0					  ;3.30
+Sector_Size		dw	0					  ;3.30
+Reserved_Sectors	dw	0					  ;3.30
+Last_Found_Cluster	dw	0					  ;3.30
+Next_BIO_Location	dw	0					  ;3.30
+First_Sector		dw	0					  ;3.30
+Sectors_Per_Track	dw	0					  ;3.30
+Drive_Number		db	0					  ;3.30
+FAT_Size		db	0					  ;3.30
+Media_Byte		db	0					  ;3.30
+EOF			db	0					  ;3.30
+									  ;3.30
+Stack_Frame		ENDS						  ;3.30
+									  ;3.30
+									  ;3.30
+BPB			STRUC						  ;3.30
+JUMP	DB	0							  ;3.30
+	DB	0							  ;3.30
+	DB	0							  ;3.30
+OEM	DB	"IBM  "                                                   ;3.30
+	DB	"3.3"                                                     ;3.30
+ByteSec DW	512			; SIZE OF A PHYSICAL SECTOR	  ;3.30
+cAlloc	DB	8			; SECTORS PER ALLOCATION UNIT	  ;3.30
+cSecRes DW	1			; NUMBER OF RESERVED SECTORS	  ;3.30
+cFat	DB	2			; NUMBER OF FATS		  ;3.30
+DirNum	DW	512			; NUMBER OF DIREC ENTRIES	  ;3.30
+NumSec	DW	4*17*305-1		; NUMBER OF SECTORS - NUMBER OF HI;3.30 DDEN SECTORS
+MEDIA	DB	0F8H			; MEDIA BYTE			  ;3.30
+cSecFat DW	8			; NUMBER OF FAT SECTORS 	  ;3.30
+SECLIM	DW	17			; SECTORS PER TRACK		  ;3.30
+HDLIM	DW	4			; NUMBER OF SURFACES		  ;3.30
+cSecHid DW	1			; NUMBER OF HIDDEN SECTORS	  ;3.30
+hSecHid dw	0			; high order word of Hidden Sector;3.30 s
+BNumSec dd	0			; 32 bit version of NUMBER OF SECT;3.30 ORS
+					; (when 16 bit version is zero)   ;3.30
+Other	db	6 dup(?)		; reserved for later expansion	  ;3.30
+BPB			ENDS						  ;3.30
+									  ;3.30
+									  ;3.30
+									  ;3.30
+End_Of_File	equ	0FFh						  ;3.30
+FAT12_Bit	equ	01h						  ;3.30
+FAT16_Bit	equ	04h						  ;3.30
+									  ;3.30
+

SRC/BIOS/MSLPT.ASM

@@ -0,0 +1,274 @@
+	TITLE MSLPT - DOS 3.3						  ;3.30
+;----------------------------------------------------------------
+;								:
+;	P R N - PRINTER DEVICE					:
+;								:
+;								:
+;   This file contains the Printer Device Driver.  The		:
+; printer driver handles calls to the printers.  Four devices	:
+; use this code: PRN, LPT1, LPT2, and LPT3.  The beginning	:
+; of the interrupt entry point for these device sets the	:
+; variable AUXNUM in the msbio.asm module.  The number is	:
+; in AUXNUM dictates which device will to written to: 0 for	:
+; PRN and LPT1, 1 for LPT2, and 2 for LPT3.			:
+;								:
+;   The routines in this files are:				:
+;								:
+;	routine 		function			:
+;	------- 		--------			:
+;	PRN$WRIT		Write to printer device 	:
+;	PRN$STAT		Printer status routine		:
+;	PRN$TilBusy		Print spooler routine		:
+;	Prn$GenIOCTL		Generic IOCTL routine		:
+;								:
+;  These routines are not called directly.  Call are made via	:
+; the strategy and interrupt entry point (see Device Header).	:
+;								:
+;----------------------------------------------------------------
+
+	test=0								  ;3.30
+	INCLUDE MSGROUP.INC	;DEFINE CODE SEGMENT			  ;3.30
+	INCLUDE MSEQU.INC						  ;3.30
+	INCLUDE MSMACRO.INC						  ;3.30
+	INCLUDE DEVSYM.INC						  ;3.30
+	INCLUDE IOCTL.INC						  ;3.30
+									  ;3.30
+	EXTRN BUS$EXIT:NEAR		;MSBIO1 			  ;3.30
+	EXTRN ERR$CNT:NEAR		;MSBIO1 			  ;3.30
+	EXTRN CMDERR:NEAR		;MSBIO1 			  ;3.30
+	EXTRN GETDX:NEAR		;MSBIO1 			  ;3.30
+	EXTRN EXIT:NEAR 		;MSBIO1 			  ;3.30
+	EXTRN ERR$EXIT:NEAR		;MSBIO1 			  ;3.30
+;DATA									  ;3.30
+	EXTRN PTRSAV:DWORD		;MSBIO1 			  ;3.30
+	EXTRN TIMDEV:WORD		;MSCLOCK			  ;3.30
+	EXTRN LPT2DEV:WORD		;MSBIO2 			  ;3.30
+	EXTRN WAIT_COUNT:WORD		;MSDATA 			  ;3.30
+	EXTRN PRINTDEV:BYTE		;MSDATA 			  ;3.30
+									  ;3.30
+
+
+; IBM ROM STATUS BITS (I DON'T TRUST THEM, NEITHER SHOULD YOU)            ;3.30
+									  ;3.30
+NOTBUSYSTATUS	=   10000000B		; NOT BUSY			  ;3.30
+ACKSTATUS	=   01000000B		; ACKNOWLEDGE (FOR WHAT?)	  ;3.30
+NOPAPERSTATUS	=   00100000B		; NO MORE PAPER 		  ;3.30
+SELECTEDSTATUS	=   00010000B		; THE PRINTER SAID IT WAS SELECTED;3.30
+IOERRSTATUS	=   00001000B		; SOME KINDA ERROR		  ;3.30
+RESERVED	=   00000110B		; NOPS				  ;3.30
+TIMEOUTSTATUS	=   00000001B		; TIME OUT.			  ;3.30
+									  ;3.30
+									  ;3.30
+; WARNING!!!  THE IBM ROM DOES NOT RETURN JUST ONE BIT.  IT RETURNS A	  ;3.30
+; WHOLE SLEW OF BITS, ONLY ONE OF WHICH IS CORRECT.			  ;3.30
+									  ;3.30
+
+;----------------------------------------------------------------
+;								:
+;		WRITE TO PRINTER DEVICE 			:
+;								:
+;   CX has count of bytes to be printed 			:
+;   ES:DI point to source buffer contains characters		:
+;   AuxNum (in msbio.asm) has printer number			:
+;								:
+;----------------------------------------------------------------
+	PUBLIC PRN$WRIT 						  ;3.30
+PRN$WRIT PROC	NEAR							  ;3.30
+	ASSUME	DS:CODE 		; SET BY PRINTER DEVICE DRIVER ENT;3.30 RY
+
+	jcxz	EXVEC3			; no chars to output, Get out
+PRN$LOOP:
+	mov	BX,2			; Initialize retry flag
+PRN$out:
+	mov	AL,ES:[DI]		; Get a character into AL
+	inc	DI			; Point to next character
+	XOR	AH,AH			; AH=0 => OUTPUT CHAR IN DL	  ;3.30
+	call	PRNOP			; print character
+	jnz	PrRetry 		; if error, try to print again
+	loop	PRN$LOOP		; if more character, keep printing
+EXVEC3:
+	jmp	EXIT
+
+PrRetry:
+	dec	DI			; undo the inc above...
+	dec	BX			; Decrement retry count
+	jnz	PRN$out 		; See if done with retrys
+PMESSG:
+	JMP	ERR$CNT 		;   if so return with the error
+PRN$WRIT ENDP								  ;3.30
+
+;----------------------------------------------------------------
+;								:
+;		PRINTER STATUS ROUTINE				:
+;								:
+;----------------------------------------------------------------
+;
+	PUBLIC PRN$STAT 						  ;3.30
+PRN$STAT PROC	NEAR							  ;3.30
+	ASSUME	DS:CODE 		; SET BY PRINTER DEVICE DRIVER ENT;3.30 RY
+									  ;3.30
+	call	PRNSTAT 		; get the status
+	jnz	PMESSG			; if error jump to error routine
+	MOV	AL,9			; AGAIN, ASSUME OUT OF PAPER...   ;3.30
+	TEST	AH,NOPAPERSTATUS					  ;3.30
+	JNZ	PMESSG							  ;3.30
+	TEST	AH,NOTBUSYSTATUS					  ;3.30
+	jnz	EXVEC3			; if not busy return via EXVEC3
+	JMP	BUS$EXIT		; else busy, return to busy exit  ;3.30
+PRN$STAT ENDP								  ;3.30
+
+
+
+;
+;   PRNSTAT	get printer status
+;   PRNOP	print a character
+;
+; PRNSTAT and PRNOP are two routines which call on the ROM-BIOS
+; printer routines.  The routines share code which calls on the bios and
+; then determines which, if any, error occured.  PRNSTAT and PRNOP differ
+; only by the value put into AH before the ROM-BIOS call.
+;
+;   INPUT	if PRNOP then character in AL
+;
+;   OUTPUT	- AL holds error code
+;		- AH status byte from printer
+;		- flag NZ if error
+PRNSTAT PROC	NEAR							  ;3.30
+	mov	AH, 2			; set command for get status  ;3.30*
+PRNOP:								      ;3.30*
+	call	GETDX			; determine which printer     ;3.30*
+	int	17h			; call ROM-BIOS printer routine ;3.30*
+
+	TEST	AH,IOERRSTATUS		; I/O ERROR?			  ;3.30
+	JZ	CHECKNOTREADY		; NO, TRY NOT READY		  ;3.30
+									  ;3.30
+; AT THIS POINT, WE KNOW WE HAVE AN ERROR.  THE CONVERSE IS NOT TRUE.	  ;3.30
+									  ;3.30
+	MOV	AL,9			; FIRST, ASSUME OUT OF PAPER	  ;3.30
+	TEST	AH,NOPAPERSTATUS	; OUT OF PAPER SET?		  ;3.30
+	JNZ	RET1			; YES, ERROR IS SET		  ;3.30
+	INC	AL			; INDICATE I/O ERROR		  ;3.30
+RET1:									  ;3.30
+									  ;3.30
+; WE HAVE TRIAGED NOW FOR OUT OF PAPER AND IO ERR (IGNORING TIME-OUT)	  ;3.30
+									  ;3.30
+	RET				; RETURN WITH ERROR		  ;3.30
+									  ;3.30
+; THE BITS SAID NO ERROR.  UNFORTUNATELY, THERE MAY BE OTHER THINGS AT WOR;3.30 K
+; HERE. 								  ;3.30
+									  ;3.30
+CHECKNOTREADY:								  ;3.30
+	MOV	AL,2			; ASSUME NOT-READY		  ;3.30
+	TEST	AH,TIMEOUTSTATUS	; IS TIME-OUT SET?		  ;3.30
+					; IF NZ THEN ERROR, ELSE OK???	  ;3.30
+PRNOP2: 								  ;3.30
+	RET								  ;3.30
+PRNSTAT ENDP								  ;3.30
+
+
+;----------------------------------------------------------------
+;								:
+;		Output until Busy				:
+;								:
+; Output until busy.  This entry point is used EXCLUSIVELY by	:
+; the print spoolers.  Under no curcumstances should the device :
+; driver block waiting for the device to become ready.		:
+;								:
+;   Inputs:	CX has count of bytes to output.		:
+;		ES:DI points to source buffer			:
+;   Outputs:	Set the number of bytes transferred		:
+;		  appropriately.				:
+;								:
+;----------------------------------------------------------------
+
+	PUBLIC	PRN$TILBUSY						  ;3.30
+PRN$TILBUSY PROC NEAR							  ;3.30
+	ASSUME	DS:CODE 		; SET BY PRINTER DEVICE DRIVER ENT;3.30 RY
+									  ;3.30
+	push	DS			; save DS
+	push	ES			; copy ES to DS
+	pop	DS
+	ASSUME	DS:NOTHING						  ;3.30
+
+	mov	SI,DI			; everything is set for LODSB
+PRN$TilBLoop:
+	push	CX
+	push	BX
+	xor	BX,BX
+	mov	BL,CS:[PRINTDEV]
+	shl	BX,1
+	mov	CX,CS:WAIT_COUNT[BX]	; wait COUNT times to come ready
+	pop	BX
+PRN$GetStat:
+	call	PrnStat 		; get status
+	jnz	PRN$BPERR	; if error jump to error routine
+	TEST	AH,10000000B		; READY YET?			  ;3.30
+	loopz	PRN$GetStat	; if busy keep trying
+	pop	CX			; get original count
+	jz	PRN$BErr		; still not ready => done
+	lodsb
+	XOR	AH,AH							  ;3.30
+	call	PrnOp			; print the character
+	jnz	PRN$BErr		; error
+	loop	PRN$TilBLoop		; go for more
+PRN$B:
+	pop	DS			; recover DS
+	lds	BX,CS:[PTRSAV]		; get pointer to header
+	ASSUME	DS:NOTHING						  ;3.30
+
+	sub	WORD PTR [BX].COUNT,CX	; Determine number of succ. I/O's
+	jmp	Exit			; all done, successful return
+PRN$TILBUSY ENDP							  ;3.30
+
+PRN$BPERR PROC	NEAR							  ;3.30
+	ASSUME	DS:CODE 						  ;3.30
+
+	pop	CX			; recover number of char left
+PRN$BErr:
+	pop	DS			; get pointer to header
+	lds	BX,CS:[PTRSAV]
+	ASSUME	DS:NOTHING						  ;3.30
+
+	sub	WORD PTR [BX].COUNT,CX	; Determine number of succ. I/O's
+	jmp	err$exit		; jump to error exit
+PRN$BPERR ENDP								  ;3.30
+
+
+;
+; Prn$GenIOCTL:
+;
+; Manipulates the value in WAIT_COUNT depending on the value passed in the
+; Generic IOCTL packet.
+; It either sets or returns the current value for the retry count for the
+; device.
+;
+	PUBLIC PRN$GENIOCTL						  ;3.30
+PRN$GENIOCTL PROC NEAR							  ;3.30
+	ASSUME	DS:CODE 		; SET BY PRINTER DEVICE DRIVER ENT;3.30 RY
+
+	les	di,[PTRSAV]
+	cmp	es:[di].MajorFunction,IOC_PC
+	je	PrnFunc_OK
+PrnFuncErr:
+	jmp	CMDERR
+
+PrnFunc_OK:
+	mov	al,es:[di].MinorFunction
+	les	di,es:[di].GenericIOCTL_Packet
+	xor	bx,bx
+	mov	bl,[PRINTDEV]		; get index into retry counts
+	shl	bx,1
+	mov	CX,WAIT_COUNT[BX]	; pull out retry count for device
+	cmp	al,GET_RETRY_COUNT
+	jz	PrnGetCount
+	cmp	al,SET_RETRY_COUNT
+	jnz	PrnFuncErr
+	mov	cx,es:[di].RC_Count
+PrnGetCount:
+	mov	WAIT_COUNT[BX],CX	; place "new" retry count
+	mov	es:[di].RC_Count,cx	; return current retry count
+	jmp	EXIT
+
+PRN$GENIOCTL ENDP							  ;3.30
+CODE	ENDS								  ;3.30
+	END								  ;3.30

SRC/BIOS/MSMACRO.INC

@@ -0,0 +1,192 @@
+;
+; This file contains three macros used in debugging the system.  If the
+; variable "test" (in msbio.asm) is nonzero code is included in the
+; modules to print debugging messages.	The level of debugging is controlled
+; by the value of the variable fTestBits in msbio.asm.	Specific bits in
+; the variable determine which messages to print.  The equ's below tell
+; which bits control which funcitons.  For example the fifth bit
+; cooresponds to disk activity (see fTestDisk equ below).
+;
+;   The macros in the file are:
+;
+;	message    Prints an ascii string on the screen.
+;		   Example usage:
+;
+;		      message fTestDisk, <"Start Disk Write", CR, LF>
+;		      message fTestINIT, <"Begin BDS initialization">
+;
+;
+;	MNUM	   Print the value in a register or memory location on
+;		   the screen. Value is displayed in hex.
+;		   Usage:
+;		      MNUM  bitpattern, valueLocation
+;
+;		   valueLocation is typically a regester:
+;
+;		      mnum  fTestCom, AX
+;		      mnum  fTestDisk, DX
+;
+;		   ValueLocation can also be a memory location:
+;
+;		      mnum  fTestINIT, Final_Dos_Location
+;
+;		   If no valueLocation is given the macro defaults to
+;		   the BX register.
+;
+;	ZWAIT	    Stops the program until any key is pressed.
+;
+;
+;	The three macros preserve all register values.	If "test" is zero
+;	defined during assembly then the  marco produce no code.
+;
+
+	IF	TEST							  ;3.30
+	   IFNDEF MSGOUT						  ;3.30
+		EXTRN	MSGOUT:NEAR,MSGNUM:NEAR 			  ;3.30
+	   ENDIF							  ;3.30
+	   IFNDEF NUMBUF						  ;3.30
+	    EXTRN   NUMBUF:BYTE,DIGITS:BYTE,FTESTBITS:WORD		  ;3.30
+	   ENDIF							  ;3.30
+	   IFNDEF DUMPBYTES						  ;3.30
+		EXTRN	DUMPBYTES:NEAR,OUTCHAR:NEAR,HEX_TO_ASCII:NEAR	  ;3.30
+	   ENDIF							  ;3.30
+
+
+
+fTestALL    equ     1111111111111111b	; watch everything
+fTestHARD   equ     0000000000000001b	; watch hard disk initialization
+fTest96     equ     0000000000000010b	; watch 96 tpi activity
+FTEST13     EQU     0000000000000100B	; WATCH INT 13 ACTIVITY 	  ;3.30
+FTESTCOM    EQU     0000000000001000B	; WATCH PACKET ACTIVITY 	  ;3.30
+FTESTINIT   EQU     0000000000010000B	; WATCH INITIALIZATION MESSAGES   ;3.30
+FTESTDISK   EQU     0000000000100000B	; WATCH DISK DEVICE DRIVER CALLS  ;3.30
+FTESTCON    EQU     0000000001000000B	; WATCH SYSTEM WAIT ACTIVITY IN CO;3.30 NSOLE
+FtestClock  equ     0000000010000000b	; wathc clock device  5/2/86  ;3.30
+
+
+;
+; message macro -- see above for description
+;
+
+MESSAGE MACRO	Bits,msg
+	    LOCAL   A,B 						  ;3.30
+	jmp	SHORT b
+a:	db	msg,0
+b:	push	SI
+	push	AX
+	mov	AX,Bits
+	mov	SI,OFFSET a
+	call	MSGOUT
+	pop	AX
+	pop	SI
+endm
+
+
+;
+; mnum macro -- see above for description
+;
+
+MNum	MACRO	Bits,num
+	push	AX
+ifb <num>
+	mov	AX,Bits
+	call	MSGNUM
+else
+	push	BX
+	mov	BX,num
+	mov	AX,Bits
+	call	MSGNUM
+	pop	BX
+endif
+	pop	AX
+endm
+
+
+;
+; zwait macro -- see above for description
+;
+
+ZWAIT	MACRO
+	Message fTestALL,<"? ">
+	CALL	ZWAITrtn
+ENDM
+
+ZWAITrtn:
+	pushf				; save the flags
+	push	AX			; preserve AX
+	xor	AH, AH			; set command to get character ;3.30*
+	int	16h			; call rom keyboard routine    ;3.30*
+	pop	AX			; restore AX
+	popf				; restore the flags
+	ret
+
+;Dump_byte dumps the memory contents in hex. 				  ;3.30
+;DUMPOFFLABEL should be a label or a variable defined in DUMPSEG.	  ;3.30
+DUMP_BYTE	MACRO	DUMPSEG, DUMPOFFLABEL, BYTELENGTH		  ;3.30
+	push	es							  ;3.30
+	PUSH	DS							  ;3.30
+	PUSH	SI							  ;3.30
+	PUSH	CX							  ;3.30
+									  ;3.30
+	MOV	CX, DUMPSEG						  ;3.30
+	MOV	DS, CX							  ;3.30
+	MOV	SI, OFFSET DUMPOFFLABEL 				  ;3.30
+	MOV	CX, BYTELENGTH						  ;3.30
+	call	dumpbytes						  ;3.30
+									  ;3.30
+	POP	CX							  ;3.30
+	POP	SI							  ;3.30
+	POP	DS							  ;3.30
+	pop	es							  ;3.30
+	ENDM								  ;3.30
+									  ;3.30
+;Dump_Byte_Reg dumps the memory contents in hex. -  4/9/86		  ;3.30
+;DUMPOFFREG should be a register contains the offset value in DUMPSEG.	  ;3.30
+DUMP_BYTE_REG	MACRO	DUMPSEG, DUMPOFFREG, BYTELENGTH 		  ;3.30
+	push	es							  ;3.30
+	PUSH	DS							  ;3.30
+	PUSH	SI							  ;3.30
+	PUSH	CX							  ;3.30
+									  ;3.30
+	MOV	CX, DUMPSEG						  ;3.30
+	MOV	DS, CX							  ;3.30
+	MOV	SI, DUMPOFFREG						  ;3.30
+	MOV	CX, BYTELENGTH						  ;3.30
+	call	dumpbytes						  ;3.30
+									  ;3.30
+	POP	CX							  ;3.30
+	POP	SI							  ;3.30
+	POP	DS							  ;3.30
+	pop	es							  ;3.30
+	ENDM								  ;3.30
+
+else
+		; if test is not defined then make macro into null statements
+Message macro
+ENDM
+
+MNUM	macro
+ENDM
+
+ZWAIT	macro
+ENDM
+
+DUMP_BYTE   MACRO							  ;3.30
+	    ENDM							  ;3.30
+DUMP_BYTE_REG MACRO							  ;3.30
+	    ENDM							  ;3.30
+	ENDIF								  ;3.30
+									  ;3.30
+PATHSTART MACRO INDEX,ABBR						  ;3.30
+	IFDEF	PATHGEN 						  ;3.30
+	    PUBLIC  ABBR&INDEX&S,ABBR&INDEX&E				  ;3.30
+	    ABBR&INDEX&S LABEL	 BYTE					  ;3.30
+	ENDIF								  ;3.30
+	ENDM								  ;3.30
+									  ;3.30
+PATHEND MACRO	INDEX,ABBR						  ;3.30
+	IFDEF	PATHGEN 						  ;3.30
+	    ABBR&INDEX&E LABEL	 BYTE					  ;3.30
+	ENDIF								  ;3.30
+	ENDM								  ;3.30
+

SRC/BIOS/MSSTACK.INC

@@ -0,0 +1,306 @@
+;	MSStack.inc
+;
+;	Interrupt level 2, 3, 4, 5, 6, 7,(10, 11, 12, 14, 15 - AT level)
+;	should follow the standard Interrupt Sharing Scheme which has
+;	a standard header structure.
+;	Fyi, the following shows the relations between
+;	the interrupt vector and interrupt level.
+; VEC(Hex)    2  8  9  A  B  C	D  E  70  72  73  74  76  77
+; LVL(Deci)   9  0  1  2  3  4	5  6   8  10  11  12  14  15
+;	MSSTACK module modifies the following interrupt vectors
+;	to meet the standard Interrupt Sharing standard;
+;	  A, B, C, D, E, 72, 73, 74, 76, 77.
+;	Also, for interrupt level 7 and 15, the FirstFlag in a standard header
+;	should be initialized to indicat whether this interrupt handler is
+;	the first (= 80h) or not.  The FirstFlag entry of INT77h's
+;	program header is initialized in STKINIT.INC module.
+;	FirstFlag is only meaningful for interrupt level 7 and 15.
+;
+
+;  User specifies the number of stack elements - default = 9
+;						 minimum = 8
+;						 maximum = 64
+;
+;  Intercepts Asynchronous Hardware Interrupts only
+;
+;  Picks a stack from pool of stacks and switches to it
+;
+;  Calls the previously saved interrupt vector after pushing flags
+;
+;  On return, returns the stack to the stack pool
+;
+
+
+; This is a modification of STACKS:
+; 1. To fix a bug which was causing the program to take up too much space.
+; 2. To dispense stack space from hi-mem first rather than low-mem first.
+;    . Clobbers the stack that got too big instead of innocent stack
+;    . Allows system to work if the only stack that got too big was the most
+;      deeply nested one
+; 3. Disables NMI interrupts while setting the NMI vector.
+; 4. Does not intercept any interupts on a PCjr.
+; 5. Double checks that a nested interrupt didn't get the same stack.
+; 6. Intercepts Ints 70, 72-77 for PC-ATs and other future products
+
+;The following variables are for MSSTACK.inc
+		EVEN
+		dw	0	; SPARE FIELD BUT LEAVE THESE IN ORDER
+StackCount	dw	0
+StackAt 	dw	0
+StackSize	dw	0
+Stacks		dw	0
+		dw	0
+
+FirstEntry	dw	Stacks
+LastEntry	dw	Stacks+(DefaultCount*EntrySize)-EntrySize
+NextEntry	dw	Stacks+(DefaultCount*EntrySize)-EntrySize
+
+;End of variables defined for MSSTACK.
+
+;*******************************************************************
+;Macro Interrupt handler for the ordinary interrupt vectors and
+;the shared interrupt vectors.
+;*****************************
+Stack_Main	MACRO	AA
+	ASSUME	DS:NOTHING
+	ASSUME	ES:NOTHING
+	ASSUME	SS:NOTHING
+PUBLIC	Int&AA
+PUBLIC	Old&AA
+;-----------------------------
+	ife	IntSharingFlag		;if not IntSharingFlag
+;-----------------------------
+	Old&AA	DD	0
+Int&AA	PROC	FAR
+;-----------------------------
+    else				;for shared interrupt. A Header exists.
+
+PUBLIC	FirstFlag&AA
+Int&AA	PROC	FAR
+	jmp	short	  Entry_Int&AA&_Stk
+	Old&AA	dd	  0		;Forward pointer
+		dw	  424Bh 	;compatible signature for Int. Sharing
+	FirstFlag&AA db   0		;the firstly hooked.
+	jmp	short	Intret_&AA	;Reset routine. We don't care this.
+		db	  7 dup (0)	;Reserved for future.
+Entry_Int&AA&_Stk:
+;-----------------------------
+	endif
+;-----------------------------
+
+;
+; Keyboard interrupt must have a three byte jump, a NOP and a zero byte
+; as its first instruction for compatibility reasons
+	ifidn	<&aa>,<09>
+	jmp	Keyboard_lbl
+	nop
+	db	0
+Keyboard_lbl	label	near
+	endif
+
+; This patches INTERRUPT 75h to be "unhooked".  We do this Wierdness,
+; rather than never hooking INT 75h, to maintain maximum compat. with IBMs
+; post production patch.
+	push	ax
+
+	ifidn	<&aa>,<02>
+
+; *********************************************************************
+;
+; This is special support for the P12 / NMI handler
+;
+;	On the P12, there is a situation where an NMI can be caused by
+;	using the "OUT" instructions to certain ports.  When this
+;	occurs, the P12 hardware *GUARANTEES* that **NOTHING** can stop
+;	the NMI or interfere with getting to the NMI handler.  This
+;	includes other type of interrupts (hardware and software), and
+;	also includes other type of NMI's.  When any NMI has occured,
+;	no other interrtupt (hardware, software or NMI) can occur until
+;	the software takes specific steps to allow further interrupting.
+;
+;	For P12, the situation where the NMI is generated by the "OUT"
+;	to a control port requires "fixing-up" and re-attempting.  In
+;	otherwords, it is actually a "restartable exception".  In this
+;	case, the software handler must be able to get to the stack in
+;	order to figure out what instruction caused the problem, where
+;	it was "OUT"ing to and what value it was "OUT"ing.  Therefore,
+;	we will not switch stacks in this situation.  This situation is
+;	detected by interrogating port 62h, and checking for a bit value
+;	of 80h.  If set, *****DO NOT SWITCH STACKS*****.
+;
+; *********************************************************************
+
+	push	es
+	mov	ax,0f000h
+	mov	es,ax
+	cmp	byte ptr es:[0fffeh],0f9h ;check if P12
+	pop	es
+	jne	Normal&aa
+
+	in	al,62h
+	test	al,80h
+	jz	Normal&aa
+
+Special&aa:
+	pop	ax
+	jmp	dword ptr Old&aa
+
+Normal&aa:
+
+; *********************************************************************
+
+	endif
+
+	push	bp
+	push	es
+	mov	es, cs:[STACKS+2]	; Get segment of stacks
+
+	mov	bp,NextEntry		; get most likely candidate
+	mov	al,Allocated
+	xchg	AllocByte,al		; grab the entry
+	cmp	al,Free 		; still avail?
+	jne	NotFree&aa
+
+	sub	NextEntry,EntrySize	; set for next interrupt
+
+Found&aa:
+	mov	SavedSP,sp		; save sp value
+	mov	SavedSS,ss		; save ss also
+;	mov	IntLevel,aa&h		; save the int level
+
+	mov	ax,bp			; temp save of table offset
+
+	mov	bp,NewSP		; get new SP value
+	cmp	es:[bp],ax		; check for offset into table
+	jne	FoundBad&aa
+
+	mov	ax,es			; point ss,sp to the new stack
+	mov	ss,ax
+	mov	sp,bp
+
+	pushf				; go execute the real interrupt handler
+	call	dword ptr old&aa	;  which will iret back to here
+
+	mov	bp,sp			; retrieve the table offset for us
+	mov	bp,es:[bp]		   ;  but leave it on the stack
+	mov	ss,SavedSS	     ; get old stack back
+	mov	sp,SavedSP
+
+;	cmp	AllocByte,Allocated	; If an error occured,
+;	jne	NewError&aa		;  do not free us
+
+	mov	AllocByte,Free		; free the entry
+	mov	NextEntry,bp		; setup to use next time
+
+NewError&aa:
+	pop	es
+	pop	bp			; saved on entry
+	pop	ax			; saved on entry
+
+INTRET_&AA:								  ;3.30
+	iret				; done with this interrupt
+
+NotFree&aa:
+	cmp	al,Allocated		; error flag
+	je	findnext&aa		;  no, continue
+	xchg	AllocByte,al		;  yes, restore error value
+
+FindNext&aa:
+	call	LongPath
+	jmp	Found&aa
+
+FoundBad&aa:
+	cmp	bp,FirstEntry
+	jc	findnext&aa
+	mov	bp,ax			; flag this entry
+	mov	AllocByte,Clobbered
+;	add	bp,EntrySize		;  and previous entry
+;	mov	AllocByte,Overflowed
+;	sub	bp,EntrySize
+	jmp	findnext&aa		; keep looking
+
+int&aa	endp
+
+
+	endm
+
+;*****************************						  ;3.30
+;End of Macro definition						  ;3.30
+;********************************************************************	  ;3.30
+; THESE ARE THE INDIVIDUAL INTERRUPT HANDLERS				  ;3.30
+									  ;3.30
+	IRP	A,<02,08,09,70> 					  ;3.30
+	IntSharingFlag=0						  ;3.30
+	Stack_Main &A							  ;3.30
+	ENDM								  ;3.30
+									  ;3.30
+	IRP	A,<0A,0B,0C,0D,0E,72,73,74,76,77>			  ;3.30
+	IntSharingFlag=1						  ;3.30
+	Stack_Main &A							  ;3.30
+	ENDM								  ;3.30
+									  ;3.30
+;********************************************************************	  ;3.30
+;Common routines							  ;3.30
+
+longpath:
+	mov	bp,LastEntry		; start with last entry in table
+
+LPLOOPP:								  ;3.30
+	cmp	AllocByte,Free		; is entry free?
+	jne	inuse			;  no, try next one
+
+	mov	al,Allocated
+	xchg	AllocByte,al		; allocate entry
+	cmp	al,Free 		; is it still free?
+	je	found			;  yes, go use it
+
+	cmp	al,Allocated		; is it other than Allocated or Free?
+	je	inuse			;  no, check the next one
+
+	mov	AllocByte,al		;  yes, put back the error state
+
+inuse:
+	cmp	bp,FirstEntry
+	je	Fatal
+	sub	bp,EntrySize
+	JMP	LPLOOPP 						  ;3.30
+
+found:
+	ret
+
+	page
+
+fatal	proc	near
+	push	ds							  ;3.30
+	mov	ax, 0f000h		;loook at the model byte	  ;3.30
+	mov	ds, ax							  ;3.30
+	cmp	ds:byte ptr [0fffeh], 0f9h	;convertible		  ;3.30
+	pop	ds							  ;3.30
+	jne	Skip_NMIS						  ;3.30
+									  ;3.30
+	mov	al,07h				; disable p12 NMIs
+	out	72h,al
+
+Skip_NMIS:								  ;3.30
+	cli					; disable and mask
+	mov	al,0ffh 			;   all other ints
+	out	021h,al
+	out	0a1h,al
+
+	mov	si,cs
+	mov	ds,si
+	mov	si,offset fatal_msg
+
+fatal_loop:
+	lodsb
+	cmp	al,'$'
+	je	fatal_done
+
+	mov	bl,7						      ;3.30*
+	mov	ah,14						      ;3.30*
+	int	010h			; whoops, this enables ints   ;3.30*
+	jmp	fatal_loop
+
+fatal_done:
+	jmp	fatal_done
+fatal	endp

SRC/BIOS/MSVOLID.INC

@@ -0,0 +1,297 @@
+;-------------------------------------------------------------------------
+;
+;  File: msvolid.asm
+;	This file contains the volume_id subroutines and data structures.
+;
+;	Routines in this file are:
+;	   Set_Volume_ID       -	main routine, calls other routines.
+;	   read_volume_id      -	read the volume ID and tells if it has
+;					   been changed.
+;	   Transfer_volume_id  -	copy the volume ID from TMP to special
+;					   drive.
+;	   Check_Volume_ID     -	compare volume ID in TMP area with one
+;					   expected for drive.
+;	   Fat_Check	       -	see of the fatID has changed in the
+;					   specified drive.
+;	   Init_Vid_loop       -	set up for VID scan or move
+;
+;
+;-------------------------------------------------------------------------
+
+;
+; length of the volume id
+;
+
+vid_size    equ 12
+
+	    PATHSTART 001,VOLID 					  ;3.30
+
+;
+; null volume id
+;
+
+nul_vid db  "NO NAME    ",0
+
+;
+; data scratch area used to hold volume ids
+;
+
+tmp_vid db  "NO NAME    ",0
+
+	    PATHEND 001,VOLID						  ;3.30
+
+;
+; Set_Volume_ID
+;   If drive has changeline support, read in and set the volume_ID
+; and the last FAT_ID byte.  If no change line support then do nothing.
+;
+;   On entry:
+;	DS:DI points to the BDS for this disk.
+;	AH contains media byte
+;
+;   On Exit:
+;	Carry clear:
+;	   Successful call
+;	Carry set
+;	   Error and AX has error code
+;
+
+Set_Volume_ID:
+	PUBLIC SET_VOLUME_ID						  ;3.30
+	push	dx			; save registers
+	push	ax
+	CALL	HasChange		; does drive have changeline support?
+	jz	setvret 		; no, get out
+	push	di
+	call	read_volume_ID		; read the volume ID
+	pop	di
+	jc	SetErr			; if error go to error routine
+	call	transfer_volume_ID	; copy the volume id to special drive
+	call	ResetChanged		; restore value of change line
+
+setvret:				; SET Volume RETurn
+	clc				; no error, clear carry flag
+	pop	ax			; restore registers
+	pop	dx
+	ret
+SetErr:
+	pop	dx			; pop stack but don't overwrite AX
+	pop	dx			; restore DX
+	ret
+
+
+
+root_sec	DW	?	;Root sector #
+
+
+
+
+;
+; read_volume_id read the volume ID and tells if it has been changed.
+;
+;   On entry:
+;	DS:DI points to current BDS for drive.
+;   On Exit:
+;	Carry Clear
+;	    SI = 1  No change
+;	    SI = 0  ?
+;	    SI = -1 Change
+;
+;	Carry Set:
+;	    Error and AX has error code.
+;
+
+read_volume_id:
+	push	ES			; preserve registers
+	push	DX
+	push	CX
+	push	BX
+	push	AX
+	push	DS			; Preserve Current BDS
+	push	DI
+	push	cs			; get ES segment correct
+	pop	es
+	push	cs			; get DS segment correct
+	pop	ds
+	mov	di,offset tmp_vid
+	mov	si,offset nul_vid
+	mov	cx,vid_size
+	rep	movsb			; initialize tmp_vid to null vi_id
+
+	pop	DI			; Restore Current BDS
+	pop	DS
+	mov	al,byte ptr ds:[di].cFAT    ; # of fats
+	mov	cx,word ptr ds:[di].csecfat ; sectors / fat
+	mul	cl			    ; size taken by fats
+	add	ax,word ptr ds:[di].ressec  ; add on reserved sectors
+					; AX is now sector # (0 based)
+	mov	cs:[root_sec],ax	; set initial value
+	mov	ax,[di].cDir		; # root dir entries
+	mov	cl,4			; 16 entries/sector
+	shr	ax,cl			; divide by 16
+	mov	cx,ax			; cx is # of sectors to scan
+next_sec:
+	push	cx			; save outer loop counter
+	mov	ax,cs:[root_sec]	; get sector #
+	mov	cx,word ptr ds:[di].seclim    ; sectors / track
+	xor	DX,DX
+	div	cx
+			; set up registers for call to read_sector
+	inc	DX		; dx= sectors into track, ax= track count from 0
+	mov	cl,dl		; sector to read
+	xor	DX,DX
+	div	word ptr ds:[di].hdlim ; # heads on this disc
+	mov	dh,dl		; Head number
+	mov	ch,al		; Track #
+	call	read_sector	; get first sector of the root directory,
+				; ES:BX -> BOOT
+	jc	ReadVIDErr	; error on read
+	mov	cx,16		; # of dir entries in a block of root
+	mov	al,08h		; volume label bit
+fvid_loop:
+	cmp	byte ptr es:[bx],0	; End of dir?
+	jz	no_vid			; yes, no vol id
+	cmp	byte ptr es:[bx],0E5h	; empty entry?
+	jz	ent_loop		; yes, skip
+	test	es:[bx+11],al		; is volume label bit set in fcb?
+	jnz	found_vid		; jmp yes
+ent_loop:
+	ADD	BX,32		;MJB003 ADD LENGTH OF DIRECTORY ENTRY	  ;3.30
+	loop	fvid_loop
+	pop	cx			; outer loop
+	inc	cs:[root_sec]		; next sector
+	loop	next_sec		; continue
+NotFound:
+	XOR	SI,SI
+	jmp	short fvid_ret
+
+found_vid:
+	pop	cx			; clean stack of outer loop counter
+	mov	si,bx			; point to volume_id
+	push	ds			; preserve currnet BDS
+	push	di
+	push	es			; es:si points to volume id.
+	pop	ds			; source segment
+	push	cs
+	pop	es			; destination segment
+	mov	di,offset tmp_vid	; dest of volume_id
+	mov	cx,vid_size -1		; length of string minus NUL
+	rep	movsb			; mov volume label to tmp_vid
+	xor	al,al
+	stosb				; Null terminate
+	XOR	SI,SI
+	pop	DI			; restore current BDS
+	pop	DS
+fvid_ret:
+	pop	ax
+	clc
+RVIDRet:
+	pop	BX			; restore register
+	pop	CX
+	pop	DX
+	pop	ES
+	ret
+no_vid:
+	pop	cx			; clean stack of outer loop counter
+	jmp	NotFound		; not found
+ReadVIDErr:
+	pop	SI
+	pop	SI
+	jmp	RVIDRet
+
+
+
+;
+;   Transfer_volume_id - copy the volume ID from TMP to special drive
+;
+;   Inputs:	DS:DI nas current BDS
+;   Outputs:	BDS for drive has volume ID from TMP
+;
+
+transfer_volume_ID:
+	push	DS		; preserve current BDS
+	push	DI
+	push	ES
+	push	SI
+	push	CX
+	call	init_vid_loop
+	cld
+	rep	MOVSB		; transfer
+	pop	CX
+	pop	SI
+	pop	ES
+	pop	DI		; restore current BDS
+	pop	DS
+	ret
+
+
+;
+;   Check_Volume_ID - compare volume ID in TMP area with one expected for
+;	drive
+;
+;   Inputs:	DS:DI has current BDS for drive
+;   Outputs:	SI = 0 if compare succeeds
+;		SI = -1 if compare fails.
+
+check_volume_id:
+	push	DS			; preserve current BDS for drive
+	push	DI
+	push	ES
+	push	CX
+	call	init_vid_loop
+	cld
+	repz	cmpsb			; are the 2 volume_ids the same?
+	mov	si,0			; assume unknown
+	jz	check_vid_ret		; carry clear if jump taken
+	mov	si,-1			; failure
+check_vid_ret:
+	pop	CX
+	pop	ES
+	pop	DI			; restore current BDS
+	pop	DS
+	ret
+
+;
+;   Fat_Check - see of the fatID has changed in the specified drive.
+;	      - uses the FAT ID obtained from the boot sector.
+;
+;   Inputs:	MedByt is expected FAT ID
+;		DS:DI points to current BDS
+;   Output:	Carry Clear
+;		    SI = -1 if fat ID different,
+;		    SI = 0 otherwise
+;   No other registers changed.
+
+FAT_CHECK:
+	push	AX
+	xor	SI, SI			 ; say FAT ID's are same.
+	mov	AL, cs:MedByt
+	cmp	AL, byte ptr [DI].Mediad ; compare it with the BDS medbyte
+	jz	OKRET1			 ; carry clear
+	dec	SI
+OkRet1: clc
+	pop	AX
+	ret
+
+
+;
+;   Init_Vid_loop - set up for VID scan or move
+;
+;   Inputs:	DS:DI pionts to BDS for the drive
+;   Outputs:	DS:SI points to tmp_vid
+;		ES:DI points to vid for drive
+;		CX has size for VID compare
+;
+
+init_vid_loop:
+	push	ax
+	push	ds
+	pop	es
+	push	cs
+	pop	ds
+	mov	si,offset tmp_vid   ; source
+	add	di,volid
+	mov	cx,vid_size
+	pop	ax
+	ret
+

SRC/BIOS/PUSHPOP.INC

@@ -0,0 +1,20 @@
+	IF1								  ;3.30
+
+SaveReg MACRO	reglist 		;; push those registers
+IRP reg,<reglist>
+	?stackdepth = ?stackdepth + 1
+	PUSH	reg
+ENDM
+ENDM
+.xcref	SaveReg
+
+
+RestoreReg  MACRO   reglist		;; pop those registers
+IRP reg,<reglist>
+	?stackdepth = ?stackdepth - 1
+	POP	reg
+ENDM
+ENDM
+.xcref	RestoreReg
+
+	ENDIF								  ;3.30

SRC/BIOS/READCLOC.INC

@@ -0,0 +1,162 @@
+;	SCCSID = @(#)readclock.asm	1.2 85/07/25
+;************************************************************************
+;
+;   read_real_date reads real-time clock for date and returns the number
+;   of days elapsed since 1-1-80 in si
+;
+read_real_date: 		;mjb002
+	PUSH	AX
+	PUSH	CX
+	PUSH	DX
+	XOR	AH,AH			; throw away clock roll over  ;3.30*
+	INT	1AH						      ;3.30*
+	POP	DX
+	POP	CX
+	POP	AX
+
+	PUSH	AX
+	PUSH	BX
+	PUSH	CX
+	PUSH	DX
+	MOV	CS:DAYCNT2,1	 ;MJB002 REAL TIME CLOCK ERROR FLAG (+1 DA;3.30Y)
+	mov	ah,4		;mjb002 read date function code       ;3.30*
+	int	1ah		;mjb002 read real-time clock	      ;3.30*
+	jnc	read_ok 	;mjb002 jmp success
+	jmp	r_d_ret 	;mjb002 jmp error
+read_ok:			;mjb002 ******* get bcd values in binary *****
+	mov	byte ptr bin_date_time+0,ch  ;mjb002 store as hex value
+	mov	byte ptr bin_date_time+1,cl  ;mjb002 ...
+	mov	byte ptr bin_date_time+2,dh  ;mjb002 ...
+	mov	byte ptr bin_date_time+3,dl  ;mjb002 ...
+	MOV	CS:DAYCNT2,2	 ;MJB002 READ OF R-T CLOCK SUCCESSFUL	  ;3.30
+	call	bcd_verify	;mjb002 verify bcd values in range
+	jc	r_d_ret 	;mjb002 jmp some value out of range
+	MOV	CS:DAYCNT2,3	 ;MJB002 READ OF R-T CLOCK SUCCESSFUL	  ;3.30
+	call	date_verify	;mjb002 verify date values in range
+	jc	r_d_ret 	;mjb002 jmp some value out of range
+	MOV	CS:DAYCNT2,0	 ;MJB002 VERIFY SUCCESSFUL		  ;3.30;3.30
+	call	in_bin		;mjb002 convert date to binary
+				;mjb002 ******* years since 1-1-80 *********
+	mov	al,byte ptr bin_date_time+1  ;mjb002 get years into century
+	cbw				     ;mjb002
+	cmp	byte ptr bin_date_time+0,20  ;mjb002 20th century?
+	jnz	century_19		     ;mjb002 jmp no
+	add	ax,100		;mjb002 add in a century
+century_19:			;mjb002
+	sub	ax,80		;mjb002 subtract off 1-1-80
+	mov	cl,4		;mjb002 leap year every 4
+	div	cl		;mjb002 al= # leap year blocks, ah= remainder
+	mov	bl,ah		;mjb002 save odd years
+	cbw			;mjb002 zero ah
+	mov	cx,366+3*365	;mjb002 # of days in leap year blocks
+	mul	cx		;mjb002 dx:ax is result
+	MOV	CS:DAYCNT2,AX	 ;MJB002 SAVE COUNT OF DAYS		  ;3.30
+	mov	al,bl		;mjb002 get odd years count
+	cbw			;mjb002
+	or	ax,ax		;mjb002 is ax= 0?
+	jz	leap_year	;mjb002 jmp if none
+	mov	cx,365		;mjb002 days in year
+	mul	cx		;mjb002 dx:ax is result
+	ADD	CS:DAYCNT2,AX	 ;MJB002 ADD ON DAYS IN ODD YEARS	  ;3.30
+	jmp	short leap_adjustment	;mjb002 account for leap year
+leap_year:			;mjb002 possibly account for a leap day
+	cmp	byte ptr bin_date_time+2,2   ;mjb002 is month february
+	jbe	no_leap_adjustment  ;mjb002 jan or feb. no leap day yet.
+leap_adjustment:		;mjb002 account for leap day
+	INC	CS:DAYCNT2	 ;MJB002 ...				  ;3.30
+no_leap_adjustment:		;mjb002 ******* get days of month *******
+	mov	cl,byte ptr bin_date_time+3    ;mjb002 ...
+	xor	ch,ch		;mjb002
+	dec	cx		;mjb002 because of offset from day 1, not day 0
+	ADD	CS:DAYCNT2,CX	 ;MJB002 ******* GET DAYS IN MONTHS PRECEE;3.30DING *****
+	mov	cl,byte ptr bin_date_time+2   ;mjb002 get month
+	xor	ch,ch		;mjb002
+	dec	cx		;mjb002 january starts at offset 0
+	shl	cx,1		;mjb002 word offset
+	mov	si,offset month_table	;mjb002 beginning of month_table
+	add	si,cx		;mjb002 point into month table
+	mov	ax,word ptr [si];mjb002 get # days in previous months
+	ADD	CS:DAYCNT2,AX	 ;MJB002 ...				  ;3.30
+r_d_ret:			;mjb002
+	MOV	SI,CS:DAYCNT2	 ;MJB002 RESULT IN SI			  ;3.30
+	POP	DX
+	POP	CX
+	POP	BX
+	POP	AX
+	ret			;mjb002
+
+r_t_retj:
+	xor	cx,cx
+	xor	dx,dx
+	jmp	r_t_ret
+;
+; Read_Real_Time reads the time from the RTC. on exit, it has the number of
+; ticks (at 18.2 ticks per sec.) in CX:DX.
+;
+Read_Real_Time:
+	mov	ah,2						      ;3.30*
+	int	1AH						      ;3.30*
+	jc	r_t_retj
+oktime:
+	mov	byte ptr bin_date_time,ch	; hours
+	mov	byte ptr bin_date_time+1,cl	; minutes
+	mov	byte ptr bin_date_time+2,dh	; seconds
+	mov	byte ptr bin_date_time+3,0	; unused for time
+	call	bcd_verify
+	jc	r_t_retj
+	call	time_verify
+	jc	r_t_retj
+	call	in_bin
+	MOV	ch,byte ptr bin_date_time
+	MOV	cl,byte ptr bin_date_time+1
+	MOV	dh,byte PTR bin_date_time+2
+	MOV	dl,byte PTR bin_date_time+3
+	message ftestinit,<"Read Time   ">
+	mnum	ftestinit,cx
+	message ftestinit,<"  ">
+	mnum	ftestinit,dx
+	message ftestinit,<cr,lf>
+; get time in ticks in CX:DX
+	CALL	word ptr cs:TimeToTicks 	;3.30
+	message ftestinit,<"Conv Time   ">
+	mnum	ftestinit,cx
+	message ftestinit,<"  ">
+	mnum	ftestinit,dx
+	message ftestinit,<cr,lf>
+r_t_ret:
+	ret
+
+;
+;   in_bin converts bin_date_time values from bcd to bin
+;
+in_bin: 				     ;mjb002
+	mov	al,byte ptr bin_date_time+0  ; century or hours
+	call	bcd_to_bin		     ; ...
+	mov	byte ptr bin_date_time+0,al  ;
+	mov	al,byte ptr bin_date_time+1  ; years or minutes
+	call	bcd_to_bin		     ; ...
+	mov	byte ptr bin_date_time+1,al  ;
+	mov	al,byte ptr bin_date_time+2  ; months or seconds
+	call	bcd_to_bin		     ; ...
+	mov	byte ptr bin_date_time+2,al  ;
+	mov	al,byte ptr bin_date_time+3  ; days (not used for time)
+	call	bcd_to_bin		     ; ...
+	mov	byte ptr bin_date_time+3,al  ;
+	ret				     ;
+;
+;   bcd_to_bin converts two bcd nibbles in al (value <= 99.) to
+;   a binary representation in al
+;   ah is destroyed
+;
+bcd_to_bin:			;mjb002
+	mov	ah,al		;mjb002 copy bcd number to ah
+	and	ax,0f00fh	;mjb002 clear unwanted nibbles
+	mov	bl,al		;mjb002 save units place
+	xchg	ah,al		;mjb002 10's place to al
+	xor	ah,ah		;mjb002 ah not wanted
+	mov	cl,4		;mjb002 shift count
+	shr	ax,cl		;mjb004 swap nibbles
+	mov	cl,10		;mjb002 convert al to ...
+	mul	cl		;mjb002 ... its binary value
+	add	al,bl		;mjb002 add in units
+	ret			;mjb002

SRC/BIOS/STKINIT.INC

@@ -0,0 +1,270 @@
+;
+;	To follow the standard interrupt sharing scheme, MSSTACK.ASM	       ;3.30
+;	has been modified.  This initialization routine also has to	       ;3.30
+;	be modified because for the interrupt level 7 and 15, FirstFlag        ;3.30
+;	should be set to signal that this interrupt handler is the	       ;3.30
+;	first handler hooked to this interrupt vector.			       ;3.30
+;	We determine this by looking at the instruction pointed by	       ;3.30
+;	this vector.  If it is IRET, then this handler should be the	       ;3.30
+;	first one.  In our case, only the interrupt vector 77h is the	       ;3.30
+;	interrupt level 15. (We don't hook interrupt level 7.)                 ;3.30
+; 9/10/1986 							       ;3.30
+;	The followings are mainly due to M.R.Turner; PTM fix of P886 12/3/86   ;3.30
+;	Some design changes are needed to the above interrupt sharing	       ;3.30
+;	method.  The above sharing scheme assumes that 1). Interrupt	       ;3.30
+;	sharing is NEVER done on levels that have BIOS support. 2). "Phantom"  ;3.30
+;	interrupts would only be generated on levels 7 and 15.		       ;3.30
+;	These assumptions are not true any more. We have to use the FirstFlag  ;3.30
+;	for EVERY level of interrupt.  We will set the firstFlag on the following;3.30
+;	conditions:							       ;3.30
+;	 a.	 if the CS portion of the vector is 0000, then "first"         ;3.30
+;	 b. else if CS:IP points to valid shared header, then NOT "first"      ;3.30
+;	 c. else if CS:IP points to an IRET, then "first"                      ;3.30
+;	 d. else if CS:IP points to DUMMY, then "first"                        ;3.30
+;	where DUMMY is - the CS portion must be F000, and the IP portion must  ;3.30
+;	be equal to the value at F000:FF01. This location is the initial value ;3.30
+;	from VECTOR_TABLE for interrupt 7, one of the preserved addresses in all;3.30
+;	the BIOSes for all of the machines.				       ;3.30
+;									       ;3.30
+;	System design group requests BIOS to handle the phantom interrupts.    ;3.30
+;									       ;3.30
+;	The "Phantom" interrupt is an illegal interrupt such as an interrupt   ;3.30
+;	produced by the bogus adapter card even without interrupt request is   ;3.30
+;	set.  More specifically, 1). The 8259 has a feature when running in    ;3.30
+;	edge triggered mode to latch a pulse and present the interrupt when    ;3.30
+;	the processor indicates interrupt acknowledge (INTA).  The interrupt   ;3.30
+;	pulse was exist at the time of INTA to get a "phantom" interrupt.      ;3.30
+;	2). or, this is caused by adapter cards placing a glitch on the        ;3.30
+;	interrupt line. 						       ;3.30
+;									       ;3.30
+;	To handle those "phantom" interrupts, the main stack code will check   ;3.30
+;	the own FirstFlag, and if it is not "first" (which means the forward   ;3.30
+;	pointer points to the legal shared interrupt handler), then pass the   ;3.30
+;	control.  If it is the first, then the following action should be      ;3.30
+;	taken.	We don't have to implement skack logic in this case.           ;3.30
+;									       ;3.30
+;	To implement this logic, we rather choose a simple method.	       ;3.30
+;	If ont of the above "FirstFlag" conditions is met, we are not          ;3.30
+;	going to hook this interrupt vector.  The reason is if the original    ;3.30
+;	vector points to "IRET" and do nothing, we don't need                  ;3.30
+;	to implement the stack logic for it.  This will simplify implementation;3.30
+;	while maintaining compatibility with the old version of DOS.	       ;3.30
+;	This implies that in the main stack code, there might be a stack code  ;3.30
+;	that will never be used, a dead code.				       ;3.30
+;									       ;3.30
+; 12/3/86								       ;3.30
+									       ;3.30
+;In - CS, DS -> sysinitseg, ES -> relocated stack code & data.		       ;3.30
+									       ;3.30
+	PAGE								       ;3.30
+StackInit	proc near						       ;3.30
+									       ;3.30
+	PUSH	AX				;SAVE ALL		       ;3.30
+	PUSH	DS							       ;3.30
+	PUSH	ES							       ;3.30
+	PUSH	BX							       ;3.30
+	PUSH	CX							       ;3.30
+	PUSH	DX							       ;3.30
+	PUSH	DI							       ;3.30
+	PUSH	SI							       ;3.30
+	PUSH	BP							       ;3.30
+									       ;3.30
+;Currently ES -> stack code area					       ;3.30
+	MOV	AX, cs:[STACK_COUNT]		   ;defined in CS	       ;3.30
+	MOV	es:[STACKCOUNT], AX		   ;defined in STACK CODE AREA ;3.30
+	MOV	AX, [STACK_SIZE]		;in CS			       ;3.30
+	MOV	es:[STACKSIZE], AX		   ;			       ;3.30
+	MOV	AX, WORD PTR cs:[STACK_ADDR]	   ; OFFSET		       ;3.30
+	MOV	WORD PTR es:[STACKS], AX				       ;3.30
+	MOV	AX, WORD PTR cs:[STACK_ADDR+WORD]  ; SEGMENT		       ;3.30
+	MOV	WORD PTR es:[STACKS+WORD], AX				       ;3.30
+									       ;3.30
+; INITIALIZE THE DATA FIELDS WITH THE PARAMETERS			       ;3.30
+									       ;3.30
+; "FIRSTENTRY" WILL ALWAYS BE AT STACKS                                        ;3.30
+									       ;3.30
+	MOV	BP, word ptr es:STACKS		   ; GET OFFSET OF STACK       ;3.30
+	MOV	es:FIRSTENTRY,BP					       ;3.30
+									       ;3.30
+; THE STACKS WILL ALWAYS IMMEDIATELY FOLLOW THE TABLE ENTRIES		       ;3.30
+									       ;3.30
+	MOV	AX,ENTRYSIZE						       ;3.30
+	MOV	CX,es:STACKCOUNT					       ;3.30
+	MUL	CX							       ;3.30
+	ADD	AX,BP							       ;3.30
+	MOV	es:STACKAT,AX						       ;3.30
+	MOV	BX,AX							       ;3.30
+	SUB	BX,2							       ;3.30
+									       ;3.30
+; ZERO THE ENTIRE STACK AREA TO START WITH				       ;3.30
+									       ;3.30
+	MOV	DI,es:STACKAT						       ;3.30
+	MOV	AX,es:STACKSIZE 					       ;3.30
+	MUL	CX							       ;3.30
+	MOV	CX,AX							       ;3.30
+	xor	ax,ax							       ;3.30
+	push	es							       ;3.30
+	pop	ds				;ds = Relocated stack code seg.;3.30
+	assume	ds:nothing						       ;3.30
+;Now, DS -> stack code area						       ;3.30
+	MOV	ES, word ptr ds:[STACKS+2]	   ; GET SEGMENT OF STACK AREA.;3.30
+	CLD								       ;3.30
+	REP	STOSB							       ;3.30
+									       ;3.30
+	MOV	CX, ds:STACKCOUNT					       ;3.30
+									       ;3.30
+; LOOP FOR "COUNT" TIMES, BUILDING A TABLE ENTRY                               ;3.30
+;  cs = sysinitseg, ds = Relocated stack code seg , es = segment of stack space;3.30
+;  CX = NUMBER OF ENTRIES						       ;3.30
+;  ES:BP => BASE OF STACKS - 2						       ;3.30
+;  ES:BX => FIRST TABLE ENTRY						       ;3.30
+									       ;3.30
+BUILDLOOP:								       ;3.30
+	MOV	ALLOCBYTE,FREE						       ;3.30
+	MOV	INTLEVEL,AL			;AX = 0 		       ;3.30
+	MOV	SAVEDSP,AX						       ;3.30
+	MOV	SAVEDSS,AX						       ;3.30
+	ADD	BX,ds:STACKSIZE 					       ;3.30
+	MOV	NEWSP,BX						       ;3.30
+	MOV	ES:[BX],BP						       ;3.30
+	ADD	BP,ENTRYSIZE						       ;3.30
+									       ;3.30
+	LOOP	BUILDLOOP						       ;3.30
+									       ;3.30
+	SUB	BP,ENTRYSIZE						       ;3.30
+	MOV	ds:LASTENTRY,BP 					       ;3.30
+	MOV	ds:NEXTENTRY,BP 					       ;3.30
+									       ;3.30
+	push	ds							       ;3.30
+	mov	ax, 0f000h		;loook at the model byte	       ;3.30
+	mov	ds, ax							       ;3.30
+	cmp	ds:byte ptr [0fffeh], 0f9h	;convertible?(P12)	       ;3.30
+	pop	ds							       ;3.30
+	jne	Skip_disableNMIS					       ;3.30
+									       ;3.30
+	MOV	AL,07H				; DISABLE P12 NMIS	       ;3.30
+	OUT	72H,AL							       ;3.30
+									       ;3.30
+Skip_disableNMIS:							       ;3.30
+	XOR	AX,AX							       ;3.30
+	MOV	es,AX				;es - SEGID OF VECTOR TABLE AT 0;3.30
+	ASSUME	es:NOTHING			;ds - Relocated Stack code segment;3.30
+									       ;3.30
+	CLI								       ;3.30
+									       ;3.30
+	IRP	AA,<02,08,09,70>					       ;3.30
+									       ;3.30
+	MOV	SI,AA&H*4		;PASS WHERE VECTOR IS TO BE ADJUSTED   ;3.30
+	mov	di, offset Int19OLD&AA	       ;we have to set OLD&AA for Int19 handler too.;3.30
+	MOV	BX,OFFSET OLD&AA	;PASS WHERE TO SAVE ORIGINAL OWNER POINTER;3.30
+	MOV	DX,OFFSET INT&AA	;PASS WHERE NEW HANDLER IS	       ;3.30
+	CALL	NEW_INIT_LOOP		;ADJUST THE VECTOR TO NEW HANDLER,     ;3.30
+					;  SAVING POINTER TO ORIGINAL OWNER    ;3.30
+	ENDM								       ;3.30
+									       ;3.30
+	IRP	AA,<0A,0B,0C,0D,0E,72,73,74,76,77>	;shared interrupts     ;3.30
+									       ;3.30
+	MOV	SI,AA&H*4		;PASS WHERE VECTOR IS TO BE ADJUSTED   ;3.30
+	push	ds			;save relocated stack code segment     ;3.30
+	lds	bx, es:[si]		;ds:bx -> original interrupt handler   ;3.30
+	push	ds							       ;3.30
+	pop	dx			;dx = segment value		       ;3.30
+
+	cmp	dx,0
+	jz	int&AA&_first
+
+	cmp	byte ptr ds:[bx],0cfh	;Does vector point to an IRET?
+	jz	int&AA&_first
+
+	cmp	word ptr ds:[bx.6],424Bh ;Magic offset (see INT&AA, msstack.inc)
+	jz	int&AA&_Not_first
+
+	cmp	dx,0f000h		;ROM BIOS segment
+	jnz	int&AA&_Not_first
+
+	push	es
+	push	dx
+	mov	dx,0f000h
+	mov	es,dx
+	cmp	bx,word ptr es:0ff01h
+       	pop	dx
+	pop	es
+	jz	int&AA&_first
+
+int&AA&_Not_first:			 ;Not the first. We are going to hook vector.;3.30
+	pop	ds							       ;3.30
+	mov	di, offset Int19OLD&AA	;we have to set OLD&AA for Int19 handler too.;3.30
+	mov	BX, OFFSET OLD&AA	;PASS WHERE TO SAVE ORIGINAL OWNER POINTER;3.30
+	MOV	DX, OFFSET INT&AA	;PASS WHERE NEW HANDLER IS	       ;3.30
+	CALL	NEW_INIT_LOOP		;ADJUST THE VECTOR TO NEW HANDLER, SAVING;3.30
+					;POINTER TO ORIGINAL OWNER.	       ;3.30
+	jmp	short int&AA&_end					       ;3.30
+int&AA&_first:				 ;the first. Don't have to hook stack code.;3.30
+	pop	ds							       ;3.30
+int&AA&_end:								       ;3.30
+									       ;3.30
+	ENDM								       ;3.30
+									       ;3.30
+	push	ds							       ;3.30
+	mov	ax, 0f000h		;loook at the model byte	       ;3.30
+	mov	ds, ax							       ;3.30
+	cmp	ds:byte ptr [0fffeh], 0f9h	;convertible?(P12)	       ;3.30
+	pop	ds							       ;3.30
+	jne	Skip_EnableNMIS 					       ;3.30
+									       ;3.30
+	MOV	AL,27H				; ENABLE P12 NMIS	       ;3.30
+	OUT	72H,AL							       ;3.30
+									       ;3.30
+Skip_EnableNMIS:							       ;3.30
+	STI								       ;3.30
+	MOV	AX,code 						       ;3.30
+	MOV	DS,AX							       ;3.30
+	ASSUME	DS:CODE 						       ;3.30
+									       ;3.30
+;	MOV	SI,OFFSET STKMSG1					       ;3.30
+;	CALL	WRMSG							       ;3.30
+									       ;3.30
+	mov	[INT19SEM],1		; INDICATE THAT INT 19		       ;3.30
+					; INITIALIZATION IS COMPLETE	       ;3.30
+									       ;3.30
+	POP	BP			; RESTORE ALL			       ;3.30
+	POP	SI							       ;3.30
+	POP	DI							       ;3.30
+	POP	DX							       ;3.30
+	POP	CX							       ;3.30
+	POP	BX							       ;3.30
+									       ;3.30
+	POP	ES							       ;3.30
+	POP	DS							       ;3.30
+	assume	ds:sysinitseg						       ;3.30
+	POP	AX							       ;3.30
+	RET								       ;3.30
+STACKINIT	ENDP							       ;3.30
+;									       ;3.30
+									       ;3.30
+NEW_INIT_LOOP PROC NEAR 						       ;3.30
+;INPUT: SI=OFSET INTO VECTOR TABLE OF THE PARTICULAR INT VECTOR BEING ADJUSTED ;3.30
+;	BX=ds:OFFSET OF OLDxx, WHERE WILL BE SAVED THE POINTER TO ORIGINAL OWNER;3.30
+;	DX=ds:OFFSET OF INTxx, THE NEW INTERRUPT HANDLER		       ;3.30
+;	di=offset value of Int19OLD&AA variable in BIOS.		       ;3.30
+;	es=ZERO, SEGID OF VECTOR TABLE					       ;3.30
+;	ds=Relocated Stack code segment 				       ;3.30
+									       ;3.30
+	MOV	AX,es:[SI+0]	       ;REMEMBER OFFSET IN VECTOR	       ;3.30
+	MOV	WORD PTR ds:[BX],AX	  ; TO ORIGINAL OWNER in DS	       ;3.30
+	MOV	AX,es:[SI+2]	       ;REMEMBER SEGID IN VECTOR	       ;3.30
+	MOV	WORD PTR ds:[BX]+2,AX	  ; TO ORIGINAL OWNER in DS	       ;3.30
+	push	ds							       ;3.30
+	mov	ax, code						       ;3.30
+	mov	ds, ax			;Set Int19OLDxx value in BIOS for      ;3.30
+	mov	ax,es:[si+0]		;Int 19 handler 		       ;3.30
+	mov	word ptr ds:[di],ax					       ;3.30
+	mov	ax,es:[si+2]						       ;3.30
+	mov	word ptr ds:[di]+2,ax					       ;3.30
+	pop	ds							       ;3.30
+									       ;3.30
+	MOV	WORD PTR es:[SI+0],DX  ;SET VECTOR TO POINT TO NEW INT HANDLER ;3.30
+	MOV	es:[SI+2],ds						       ;3.30
+	RET								       ;3.30
+NEW_INIT_LOOP ENDP							       ;3.30
+									       ;3.30

SRC/BIOS/STKMES.INC

@@ -0,0 +1,6 @@
+	PUBLIC FATAL_MSG						  ;3.30
+FATAL_MSG	DB	0DH,0AH 					  ;3.30
+		DB	7,0DH,0AH					  ;3.30
+		DB	"Internal stack overflow",0DH,0AH                 ;3.30
+		DB	"System halted",0DH,0AH,"$"                       ;3.30
+;

SRC/BIOS/SYSCONF.ASM

@@ -0,0 +1,868 @@
+TITLE	BIOS SYSTEM INITIALIZATION
+TRUE	    EQU 0FFFFh
+FALSE	    EQU 0
+
+;IBMVER	   EQU	   TRUE
+;IBM	   EQU	   IBMVER
+STACKSW   EQU	   TRUE 		;Include Switchable Hardware Stacks
+;IBMJAPVER EQU	   FALSE		;If TRUE set KANJI true also
+;MSVER	   EQU	   FALSE
+;ALTVECT   EQU	   FALSE		;Switch to build ALTVECT version
+;KANJI	   EQU	   FALSE
+
+INCLUDE version.inc
+
+	IF	IBMJAPVER
+NOEXEC	EQU	TRUE
+	ELSE
+NOEXEC	EQU	FALSE
+	ENDIF
+
+DOSSIZE EQU	0A000H
+
+.xlist
+	include smdossym.inc	; Reduced version of DOSSYM.INC	  ;3.30
+	INCLUDE devsym.inc
+	include ioctl.inc
+	include BIOSTRUC.INC						  ;3.30
+.list
+
+	IF	NOT IBMJAPVER
+	EXTRN	RE_INIT:FAR
+	ENDIF
+
+SYSINITSEG	SEGMENT PUBLIC 'SYSTEM_INIT'
+
+ASSUME	CS:SYSINITSEG,DS:NOTHING,ES:NOTHING,SS:NOTHING
+
+	EXTRN	BADOPM:BYTE,CRLFM:BYTE,BADCOM:BYTE,BADMEM:BYTE,BADBLOCK:BYTE
+	EXTRN	BADSIZ_PRE:BYTE,BADLD_PRE:BYTE
+	EXTRN	BADSIZ_POST:BYTE,BADLD_POST:BYTE
+	EXTRN	BADSTACK:BYTE,BADCOUNTRYCOM:BYTE			  ;3.30
+	EXTRN	SYSSIZE:BYTE,BADCOUNTRY:BYTE,INSUFMEMORY:BYTE		  ;3.30
+	EXTRN	CONDEV:BYTE,AUXDEV:BYTE,PRNDEV:BYTE,COMMND:BYTE,CONFIG:BYTE
+	EXTRN	Cntry_Drv:BYTE,Cntry_Root:BYTE,Cntry_Path:BYTE		  ;3.30
+	EXTRN	DeviceParameters:byte					  ;3.30
+	EXTRN	MEMORY_SIZE:word					  ;3.30
+	EXTRN	BUFFERS:word						  ;3.30
+	EXTRN	FILES:byte,NUM_CDS:byte 				  ;3.30
+	EXTRN	DOSINFO:dword,ENTRY_POINT:dword 			  ;3.30
+	EXTRN	FCBS:byte,KEEP:byte					  ;3.30
+	EXTRN	CONFBOT:word,ALLOCLIM:word,COMMAND_LINE:byte		  ;3.30
+	EXTRN	ZERO:byte,SEPCHR:byte					  ;3.30
+	EXTRN	COUNT:word,CHRPTR:word,CNTRYFILEHANDLE:word		  ;3.30
+	EXTRN	MEMLO:word,MEMHI:word,PRMBLK:word,LDOFF:word		  ;3.30
+	EXTRN	PACKET:byte,UNITCOUNT:byte,BREAK_ADDR:dword		  ;3.30
+	EXTRN	BPB_ADDR:dword,DRIVENUMBER:byte,SYSI_COUNTRY:dword	  ;3.30
+									  ;3.30
+	EXTRN	MEM_ERR:NEAR,SetDOSCountryInfo:NEAR			  ;3.30
+	EXTRN	PARAROUND:NEAR,TEMPCDS:NEAR				  ;3.30
+	EXTRN	Set_Country_Path:NEAR,Move_ASCIIZ:NEAR,DELIM:NEAR	  ;3.30
+	EXTRN	BADFIL:NEAR,ROUND:NEAR					  ;3.30
+
+	IF	STACKSW
+;
+; Internal Stack Parameters
+EntrySize		equ	8
+
+MinCount		equ	8
+DefaultCount		equ	9
+MaxCount		equ	64
+
+MinSize 		equ	32
+DefaultSize		equ	128
+MaxSize 		equ	512
+
+	extrn  stack_count:word 					  ;3.30
+	extrn  stack_size:word						  ;3.30
+	extrn  stack_addr:dword 					  ;3.30
+
+	ENDIF
+
+	PUBLIC DOCONF							  ;3.30
+	PUBLIC GETCHR							  ;3.30
+
+;*************************************************************************;3.30
+;Take care of Config.sys file.						  ;3.30
+
+DOCONF:
+	PUSH	CS
+	POP	DS
+
+	ASSUME	DS:SYSINITSEG
+
+	MOV	AX,(CHAR_OPER SHL 8)	;GET SWITCH CHARACTER
+	INT	21H
+	MOV	[COMMAND_LINE+1],DL	; Set in default command line
+
+	MOV	DX,OFFSET CONFIG	;NOW POINTING TO FILE DESCRIPTION
+	MOV	AX,OPEN SHL 8		;OPEN FILE "CONFIG.SYS"
+	STC				;IN CASE OF INT 24
+	INT	21H			;FUNCTION REQUEST
+	JC	ENDCONF 		;Wasn't there, or couldn't open   ;3.30
+	JMP	NOPROB			;PROBLEM WITH OPEN
+
+ENDCONF:								  ;3.30
+	return								  ;3.30
+
+
+BADOP:	MOV	DX,OFFSET BADOPM	;WANT TO PRINT COMMAND ERROR
+	invoke	PRINT
+	JMP	COFF
+
+NOPROB: 				;GET FILE SIZE (NOTE < 64K!!)
+	MOV	BX,AX
+	XOR	CX,CX
+	XOR	DX,DX
+	MOV	AX,(LSEEK SHL 8) OR 2
+	INT	21H
+	MOV	[COUNT],AX
+	XOR	DX,DX
+	MOV	AX,LSEEK SHL 8		;Reset pointer to beginning of file
+	INT	21H
+	MOV	DX,CS
+	MOV	AX,[COUNT]
+	call	ParaRound
+	SUB	DX,AX
+	SUB	DX,11H			;ROOM FOR HEADER
+	MOV	[CONFBOT],DX		; Config starts here
+	CALL	TEMPCDS 		; Finally get CDS to "safe" location
+ASSUME	DS:NOTHING,ES:NOTHING
+
+	MOV	DX,[CONFBOT]
+	MOV	DS,DX
+	MOV	ES,DX
+	XOR	DX,DX
+	MOV	CX,[COUNT]
+	MOV	AH,READ
+	STC				;IN CASE OF INT 24
+	INT	21H			;Function request
+	PUSHF
+;
+; Find the EOF mark in the file.  If present, then trim length.
+;
+	SaveReg <AX,DI,CX>
+	MOV	AL,1Ah			; eof mark
+	MOV	DI,DX			; point ro buffer
+	JCXZ	PutEOL			; no chars
+	REPNZ	SCASB			; find end
+	JNZ	PutEOL			; none found and count exahusted
+;
+; We found a 1A.  Back up
+;
+	DEC	DI			; backup past 1A
+;
+;  Just for the halibut, stick in an extra EOL
+;
+PutEOL:
+	MOV	AL,13
+	STOSB				; CR
+	MOV	AL,10
+	STOSB				; LF
+	SUB	DI,DX			; difference moved
+	MOV	Count,DI		; new count
+;
+; Restore registers
+;
+	RestoreReg  <CX,DI,AX>
+
+	PUSH	CS
+	POP	DS
+ASSUME	DS:SYSINITSEG
+	PUSH	AX
+	MOV	AH,CLOSE
+	INT	21H
+	POP	AX
+	POPF
+	JC	CONFERR 		;IF NOT WE'VE GOT A PROBLEM
+	CMP	CX,AX
+	JZ	GETCOM			;COULDN'T READ THE FILE
+CONFERR:
+	MOV	DX,OFFSET CONFIG	;WANT TO PRINT CONFIG ERROR
+	CALL	BADFIL
+ENDCONV:JMP	ENDCONF 						  ;3.30
+
+GETCOM:
+	invoke	ORGANIZE		;ORGANIZE THE FILE
+	CALL	GETCHR
+
+CONFLP: JC	ENDCONV 						  ;3.30
+	MOV	AH,AL
+	CALL	GETCHR
+	JNC	TryB
+	JMP	BADOP
+
+COFF:	PUSH	CS
+	POP	DS
+	invoke	NEWLINE
+	JMP	CONFLP
+
+;------------------------------------------------------------------------------
+; Buffer command
+;------------------------------------------------------------------------------
+TryB:	CMP	AH,'B'                  ;BUFFER COMMAND?
+	JNZ	TRYC
+	invoke	GETNUM
+	JZ	TryBBad 		; Gotta have at least one
+	CMP	AX,100			; check for max number
+	JB	SaveBuf
+TryBBad:JMP	BadOp
+SaveBuf:
+	MOV	[BUFFERS],AX
+CoffJ1: JMP	COFF
+
+;------------------------------------------------------------------------------
+; Break command
+;------------------------------------------------------------------------------
+TryC:	CMP	AH,'C'
+	JZ	GOTC
+	JMP	TRYD
+GOTC:
+	CMP	AL,'O'                  ;FIRST LETTER OF "ON" or "OFF"
+	JNZ	TryCBad
+	CALL	GETCHR
+	JC	TryCBad
+	CMP	AL,'N'                  ;SECOND LETTER OF "ON"
+	JNZ	TryCoff
+	MOV	AH,SET_CTRL_C_TRAPPING	;TURN ON CONTROL-C CHECK
+	MOV	AL,1
+	MOV	DL,AL
+	INT	21H
+CoffJ2: JMP	Coff
+TryCOff:CMP	AL,'F'
+	JNZ	TryCBad 		; Check for "OFF"
+	CALL	GetChr
+	JC	TryCBad
+	CMP	AL,'F'
+	JZ	COffJ2
+TryCBad:JMP	BadOp
+
+;------------------------------------------------------------------------------
+; Device command
+;------------------------------------------------------------------------------
+TRYD:	CMP	AH,'D'
+	JZ	GOTD
+	JMP	TRYQ
+GOTD:	MOV	BX,CS
+	MOV	DS,BX
+
+	MOV	WORD PTR [BPB_ADDR],SI
+	MOV	WORD PTR [BPB_ADDR+2],ES
+
+	CALL	ROUND
+	XOR	AX,AX
+	MOV	WORD PTR [ENTRY_POINT],AX
+	MOV	AX,[MEMHI]
+	MOV	WORD PTR [ENTRY_POINT+2],AX ;SET ENTRY POINT
+
+	IF	NOT NOEXEC
+	MOV	[LDOFF],AX		;SET LOAD OFFSET
+	ENDIF
+
+	PUSH	ES
+	POP	DS
+ASSUME	DS:NOTHING
+	MOV	DX,SI			;DS:DX POINTS TO FILE NAME
+
+	IF	NOEXEC
+	LES	BX,DWORD PTR CS:[MEMLO]
+	CALL	LDFIL			;LOAD IN THE DEVICE DRIVER
+	ELSE
+; We are going to open the cdevice driver and size it as is done
+;  in LDFIL. The reason we must do this is that EXEC does NO checking
+;  for us. We must make sure there is room to load the device without
+;  trashing SYSINIT. This code is not
+;  perfect (for instance .EXE device drivers are possible) because
+;  it does its sizing based on the assumption that the file being loaded
+;  is a .COM file. It is close enough to correctness to be usable.
+	MOV	ES,AX			;ES:0 is LOAD addr
+	MOV	AX,OPEN SHL 8		;OPEN THE FILE
+	STC				;IN CASE OF INT 24
+	INT	21H
+	JC	BADLDRESET
+	MOV	BX,AX			;Handle in BX
+	PUSH	DX			; Save pointer to name
+	XOR	CX,CX
+	XOR	DX,DX
+	MOV	AX,(LSEEK SHL 8) OR 2
+	STC				;IN CASE OF INT 24
+	INT	21H			; Get file size in DX:AX
+	JNC	GO_AHEAD_LOAD
+	MOV	AH,CLOSE		; Close file
+	INT	21H
+	POP	DX			; Clean stack
+	STC				; Close may clear carry
+	JMP	SHORT BADLDRESET
+
+GO_AHEAD_LOAD:
+    ; Convert size in DX:AX to para in AX
+	ADD	AX,15			; Round up size for conversion to para
+	ADC	DX,0
+	MOV	CL,4
+	SHR	AX,CL
+	MOV	CL,12
+	SHL	DX,CL			; Low nibble of DX to high nibble
+	OR	AX,DX			; AX is now # of para for file
+
+	MOV	CX,ES			; CX:0 is xaddr
+	ADD	CX,AX			; New device will take up to here
+	JC	MEM_ERRJY		; WOW!!!!
+	CMP	CX,CS:[ALLOCLIM]
+	JB	OKLDX
+MEM_ERRJY:
+	JMP	MEM_ERR
+
+OKLDX:
+	POP	DX			; Recover name pointer
+	MOV	AH,CLOSE		; Close file
+	INT	21H
+	MOV	BX,CS
+	MOV	ES,BX
+	MOV	BX,OFFSET PRMBLK	;ES:BX POINTS TO PARAMETERS
+	MOV	AL,3
+	MOV	AH,EXEC
+	STC				;IN CASE OF INT 24
+	INT	21H			;LOAD IN THE DEVICE DRIVER
+	ENDIF
+
+BADLDRESET:
+	PUSH	DS
+	POP	ES			;ES:SI BACK TO CONFIG.SYS
+	PUSH	CS
+	POP	DS			;DS BACK TO SYSINIT
+ASSUME	DS:SYSINITSEG
+	JNC	GOODLD
+BADBRK:
+	cmp	byte ptr es:[si], 13	;file name is CR?		  ;3.30
+	jne	BADBRK_1		;(entered "device=" without filename);3.30                                            ;3.30
+	jmp	BADOP			;"Unrecognized command in CONFIG.SYS";3.30
+BADBRK_1:								  ;3.30
+	invoke	BADLOAD
+	JMP	COFF
+
+GOODLD: SaveReg <ES,SI> 		;INITIALIZE THE DEVICE
+Restore:MOV	BL,ES:[SI]		;   while ((c=*p) != 0)
+	OR	BL,BL
+	JZ	Got
+	INC	SI			;	p++;
+	JMP	Restore
+Got:	MOV	BYTE PTR ES:[SI],' '    ;   *p = ' ';
+	SaveReg <ES,SI>
+	PUSH	CS
+	POP	ES
+	MOV	BX,SDEVSTRAT
+	invoke	CALLDEV 		;   CallDev (SDevStrat);
+	MOV	BX,SDEVINT
+	invoke	CALLDEV 		;   CallDev (SDevInt);
+	RestoreReg  <SI,DS>
+	MOV	BYTE PTR [SI],0 	;   *p = 0;
+
+	PUSH	CS
+	POP	DS
+	MOV	AX,WORD PTR [BREAK_ADDR+2]
+	CMP	AX,[MEMORY_SIZE]
+	JB	BREAKOK
+	POP	SI
+	POP	ES
+	JMP	BADBRK
+
+BREAKOK:
+	LDS	DX,[ENTRY_POINT]	;SET DS:DX TO HEADER
+	MOV	SI,DX
+	ADD	SI,SDEVATT		;DS:SI POINTS TO ATTRIBUTES
+	LES	DI,CS:[DOSINFO] 	;ES:DI POINT TO DOS INFO
+	MOV	AX,DS:[SI]		;GET ATTRIBUTES
+	TEST	AX,DEVTYP		;TEST IF BLOCK DEV
+	JZ	ISBLOCK
+	invoke	SET_BREAK		; Go ahead and alloc mem for device
+	jc	Erase_Dev		;dev driver's Init routine failed ;3.30
+	TEST	AX,ISCIN		;IS IT A CONSOLE IN?
+	JZ	TRYCLK
+	MOV	WORD PTR ES:[DI.SYSI_CON],DX
+	MOV	WORD PTR ES:[DI.SYSI_CON+2],DS
+
+TRYCLK: TEST	AX,ISCLOCK		;IS IT A CLOCK DEVICE?
+	JZ	GOLINK
+	MOV	WORD PTR ES:[DI+SYSI_CLOCK],DX
+	MOV	WORD PTR ES:[DI+SYSI_CLOCK+2],DS
+GOLINK: JMP	LINKIT
+
+ISBLOCK:
+	MOV	AL,CS:[UNITCOUNT]	;IF NO UNITS FOUND, erase the device
+	OR	AL,AL
+	JNZ	PERDRV
+ERASE_DEV:
+	MOV	AX,-1			; No call to SET_BREAK yet, so no alloc
+	JMP	ENDDEV
+
+PERDRV:
+	CBW				; WARNING NO DEVICE > 127 UNITS
+	MOV	CX,AX
+	MOV	DH,AH
+	MOV	DL,ES:[DI.SYSI_NUMIO]	;GET NUMBER OF DEVICES
+	MOV	AH,DL
+	ADD	AH,AL			; Check for too many devices
+	CMP	AH,26			; 'A' - 'Z' is 26 devices
+	JBE	OK_BLOCK
+	PUSH	CS
+	POP	DS
+	MOV	DX,OFFSET BADBLOCK
+	invoke	PRINT
+	JMP	ERASE_DEV
+
+OK_BLOCK:
+	invoke	SET_BREAK		; Alloc the device
+	ADD	ES:[DI.SYSI_NUMIO],AL	;UPDATE THE AMOUNT
+	ADD	CS:DriveNumber,AL	; remember amount for next device
+	LDS	BX,CS:[BPB_ADDR]	;POINT TO BPB ARRAY
+PERUNIT:
+	LES	BP,CS:[DOSINFO]
+	LES	BP,DWORD PTR ES:[BP.SYSI_DPB]	;GET FIRST DPB
+
+SCANDPB:CMP	WORD PTR ES:[BP.DPB_NEXT_DPB],-1
+	JZ	FOUNDPB
+	LES	BP,ES:[BP.DPB_NEXT_DPB]
+	JMP	SCANDPB
+FOUNDPB:
+	MOV	AX,CS:[MEMLO]
+	MOV	WORD PTR ES:[BP.DPB_NEXT_DPB],AX
+	MOV	AX,CS:[MEMHI]
+	MOV	WORD PTR ES:[BP.DPB_NEXT_DPB+2],AX
+	LES	BP,DWORD PTR CS:[MEMLO]
+	ADD	WORD PTR CS:[MEMLO],DPBSIZ
+	CALL	ROUND			;Check for alloc error
+	MOV	WORD PTR ES:[BP.DPB_NEXT_DPB],-1
+	MOV	ES:[BP.DPB_FIRST_ACCESS],-1
+
+	MOV	SI,[BX] 		;DS:SI POINTS TO BPB
+	INC	BX
+	INC	BX			;POINT TO NEXT GUY
+	MOV	WORD PTR ES:[BP.DPB_DRIVE],DX
+	MOV	AH,SETDPB		;HIDDEN SYSTEM CALL
+	INT	21H
+	MOV	AX,ES:[BP.DPB_SECTOR_SIZE]				  ;3.30
+	PUSH	ES							  ;3.30
+	LES	DI,CS:[DOSINFO] 	;ES:DI POINT TO DOS INFO	  ;3.30
+	CMP	AX,ES:[DI.SYSI_MAXSEC]					  ;3.30
+	POP	ES							  ;3.30
+	JBE	NOTMAX							  ;3.30
+	POP	SI							  ;3.30
+	POP	ES							  ;3.30
+	MOV	DX,OFFSET BADSIZ_PRE					  ;3.30
+	MOV	BX,OFFSET BADSIZ_POST					  ;3.30
+	invoke	PRNERR							  ;3.30
+	JMP	COFF							  ;3.30
+
+NOTMAX: PUSH	DS
+	PUSH	DX
+	LDS	DX,CS:[ENTRY_POINT]
+	MOV	WORD PTR ES:[BP.DPB_DRIVER_ADDR],DX
+	MOV	WORD PTR ES:[BP.DPB_DRIVER_ADDR+2],DS
+	POP	DX
+	POP	DS
+	INC	DX
+	INC	DH
+	LOOP	PERUNIT
+	PUSH	CS
+	POP	DS
+	CALL	TEMPCDS 		; Set CDS for new drives
+
+LINKIT:
+	LES	DI,CS:[DOSINFO] 	;ES:DI = DOS TABLE
+	MOV	CX,WORD PTR ES:[DI.SYSI_DEV]	;DX:CX = HEAD OF LIST
+	MOV	DX,WORD PTR ES:[DI.SYSI_DEV+2]
+
+	LDS	SI,CS:[ENTRY_POINT]	;DS:SI = DEVICE LOCATION
+	MOV	WORD PTR ES:[DI.SYSI_DEV],SI	;SET HEAD OF LIST IN DOS
+	MOV	WORD PTR ES:[DI.SYSI_DEV+2],DS
+	MOV	AX,DS:[SI]		;GET POINTER TO NEXT DEVICE
+	MOV	WORD PTR CS:[ENTRY_POINT],AX	;AND SAVE IT
+
+	MOV	WORD PTR DS:[SI],CX	;LINK IN THE DRIVER
+	MOV	WORD PTR DS:[SI+2],DX
+ENDDEV:
+	POP	SI
+	POP	ES
+	INC	AX			;AX = FFFF (no more devs if YES)?
+	JZ	COFFJ3
+	JMP	GOODLD			;OTHERWISE PRETEND WE LOADED IT IN
+COFFJ3: JMP	COFF
+
+;------------------------------------------------------------------------------
+; Country command
+;  The syntax is:							  ;3.30
+;	COUNTRY=country id {,codepage {,path}}				  ;3.30
+;	COUNTRY=country id {,,path}	:Default CODEPAGE ID in DOS	  ;3.30
+;------------------------------------------------------------------------------
+TRYQ:
+	CMP	AH,'Q'                                                         ;3.30
+	JZ	TRYQ_CONT						       ;3.30
+	JMP	TRYF							       ;3.30
+TRYQ_CONT:								       ;3.30
+	invoke	GETNUM							       ;3.30
+	JZ	TryQBad 		; 0 is never a valid code, or number is;3.30
+					;   bad 			       ;3.30
+	MOV	BX,AX			; Country code in BX		       ;3.30
+									       ;3.30
+					; 5/26/86			       ;3.30
+	MOV	DX,0			; assume no code page id	       ;3.30
+									       ;3.30
+	invoke	skip_delim		;skip the delimeters after the first nu;3.30m
+	jc	TryQ_Def_File		;no more characters left? then use defa;3.30ult file
+	cmp	al, 13			;				       ;3.30
+	je	TryQ_Def_File						       ;3.30
+	cmp	al, 10							       ;3.30
+	jne	TRYQ_YES_EXTENDED					       ;3.30
+	inc	[COUNT] 		;This is for NEWLINE routine in COFF.  ;3.30
+	dec	[CHRPTR]						       ;3.30
+COFFJ41:								       ;3.30
+	JMP	TryQ_Def_File		;O.K. no code page, no path specified. ;3.30Use default path.
+									       ;3.30
+TRYQ_YES_EXTENDED:							       ;3.30
+	cmp	al, ','                 ;was the second comma?                 ;3.30
+	jne	TryQ_GETNUM						       ;3.30
+	invoke	skip_delim		;Yes, skip ',' and other possible delim;3.30
+	jmp	short TRYQ_PATH 	;and No code page id entered.	       ;3.30
+TRYQ_GETNUM:								       ;3.30
+	invoke	GETNUM							       ;3.30
+	jc	TryQBadCOM		;"Country=xxx,path" will not be accepte;3.30d.
+;	jc	TRYQ_PATH		;Codepage is not specified. No code pag;3.30e.
+;					;At this point, AL already contain the ;3.30
+;					;first char of the PATH.	       ;3.30
+	jz	TryQBad 		;codepage=0 entered. Error	       ;3.30
+	mov	DX, AX			;save code page in DX		       ;3.30
+	invoke	skip_delim		;move CHRPTR to the path string        ;3.30
+	jc	TryQ_Def_File		;no more char? then use default filenam;3.30e
+	cmp	al, 13							       ;3.30
+	je	TryQ_Def_File						       ;3.30
+	cmp	al, 10							       ;3.30
+	jne	TryQ_PATH		;path entered.			       ;3.30
+	inc	[COUNT] 						       ;3.30
+	dec	[CHRPTR]						       ;3.30
+TryQ_Def_File:								       ;3.30
+	push	dx			;save code page 		       ;3.30
+	mov	cs:CNTRY_DRV, 0 	;flag that the default path has been us;3.30ed!!!
+	mov	dx, offset CNTRY_ROOT	;the default path		       ;3.30
+	jmp	TRYQ_OPEN						       ;3.30
+									       ;3.30
+TryQBad:				;"Invalid country code or code page"   ;3.30
+	STC								       ;3.30
+	MOV	DX,OFFSET BADCOUNTRY					       ;3.30
+	jmp	TryQChkErr						       ;3.30
+									       ;3.30
+TryQBadCOM:				;Error in COUNTRY command	       ;3.30
+	STC								       ;3.30
+	MOV	DX,OFFSET BADCOUNTRYCOM 				       ;3.30
+	jmp	TryQChkErr						       ;3.30
+									       ;3.30
+TRYQ_PATH:				;DS - sysinitseg, ES - CONFBOT,        ;3.30
+	mov	CX, [COUNT]		;AL - the first char of path	       ;3.30
+	inc	CX			;BX - country id, DX - codepage id, 0 =;3.30 No code page
+	mov	DI, SI							       ;3.30
+TRYQ_PATH_LOOP: 			;find the end of path to put 0 after th;3.30at.
+	mov	AL, byte ptr ES:[DI]					       ;3.30
+	call	delim							       ;3.30
+	jz	TRYQ_PATH_END						       ;3.30
+	cmp	al, 13							       ;3.30
+	jz	TRYQ_PATH_END						       ;3.30
+	inc	DI							       ;3.30
+	jmp	short TRYQ_PATH_LOOP					       ;3.30
+TryQBad_Brg:jmp short TryQBad						       ;3.30
+TRYQ_PATH_END:								       ;3.30
+	mov	es:byte ptr [di], 0	;make it a ASCIIZ string. (Organize did;3.30 not handle this string)
+	push	ds			;switch ds,es			       ;3.30
+	push	es							       ;3.30
+	pop	ds							       ;3.30
+	pop	es							       ;3.30
+									       ;3.30
+	mov	di, offset  CNTRY_DRV	;move the user specified path to CNTRY_;3.30DRV
+	call	Move_ASCIIZ						       ;3.30
+									       ;3.30
+	push	ds			;restore ds,es			       ;3.30
+	push	es							       ;3.30
+	pop	ds							       ;3.30
+	pop	es							       ;3.30
+									       ;3.30
+;	 call	 Set_Country_Path	 ;set CNTRY_DRV 		       ;3.30
+									       ;3.30
+	push	dx			;save DX			       ;3.30
+	mov	dx, offset CNTRY_DRV	;Now DS:DX -> CNTRY_DRV 	       ;3.30
+TRYQ_OPEN:								       ;3.30
+	mov	ax, 3d00h		;open a file			       ;3.30
+	stc								       ;3.30
+	int	21h							       ;3.30
+	pop	dx			;restore codepage id		       ;3.30
+	jc	TryQFileBad		;open failure			       ;3.30
+									       ;3.30
+	mov	cs:CntryFileHandle, ax	;save file handle		       ;3.30
+	xchg	ax, bx			;now, AX = country id, BX = file handle;3.30
+	mov	cx, cs:[MEMHI]						       ;3.30
+	add	cx, 128 		;I need 2K buffer to handle COUNTRY.SYS;3.30
+	cmp	cx, cs:[ALLOCLIM]					       ;3.30
+	ja	TryQMemory		;cannot allocate the buffer for country;3.30.sys
+									       ;3.30
+	mov	si, offset CNTRY_DRV	;DS:SI -> CNTRY_DRV		       ;3.30
+	cmp	byte ptr [si],0 	;default path?			       ;3.30
+	jne	TRYQ_Set_for_DOS					       ;3.30
+	inc	si							       ;3.30
+	inc	si			;DS:SI -> CNTRY_ROOT		       ;3.30
+TRYQ_Set_for_DOS:							       ;3.30
+	les	di, cs:SYSI_Country	;ES:DI -> country info tab in DOS      ;3.30
+	push	di			;save di			       ;3.30
+	add	di, ccPath_CountrySys					       ;3.30
+	call	MOVE_ASCIIZ		;Set the path to COUNTRY.SYS in DOS.   ;3.30
+	pop	di			;ES:DI -> country info tab again.      ;3.30
+	mov	cx, cs:[MEMHI]						       ;3.30
+	mov	ds, cx							       ;3.30
+	xor	si, si			;DS:SI -> 2K buffer to be used.        ;3.30
+	call	SetDOSCountryInfo	;now do the job!!!		       ;3.30
+	jnc	TryQchkERR		;read error or could not find country,c;3.30ode page combination
+	cmp	cx, -1			;Could not find matching country_id,cod;3.30e page?
+	je	TryQBad_Brg		;then "Invalid country code or code pag;3.30e"
+TryQFileBad:								       ;3.30
+	cmp	cs:CNTRY_DRV,0		;Is the default file used?	       ;3.30
+	je	TryQDefBad						       ;3.30
+	mov	si, cs:[CONFBOT]					       ;3.30
+	mov	es, si							       ;3.30
+	mov	si, cs:[CHRPTR] 					       ;3.30
+	dec	si			;ES:SI -> path in CONFBOT	       ;3.30
+	jmp	short TryQBADLOAD					       ;3.30
+TryQDefBad:				;Default file has been used.	       ;3.30
+	push	cs							       ;3.30
+	pop	es							       ;3.30
+	mov	si, offset CNTRY_ROOT	;ES:SI -> \COUNTRY.SYS in SYSINIT_SEG  ;3.30
+TryQBADLOAD:								       ;3.30
+	call	BADLOAD 		;DS will be restored to SYSINIT_SEG    ;3.30
+	mov	cx, cs:[CONFBOT]					       ;3.30
+	mov	es, cx			;Restore ES -> CONFBOT. 	       ;3.30
+	jmp	short CoffJ4						       ;3.30
+TryQMemory:								       ;3.30
+	MOV	DX,OFFSET INSUFMEMORY					       ;3.30
+TryQChkErr:								       ;3.30
+	mov	cx, cs:[CONFBOT]					       ;3.30
+	mov	es, cx			;restore ES -> CONFBOT seg	       ;3.30
+	push	cs							       ;3.30
+	pop	ds			;retore DS to SYSINIT_SEG	       ;3.30
+	jnc	CoffJ4			;if no error, then exit 	       ;3.30
+	invoke	PRINT			;else show error message	       ;3.30
+CoffJ4: 								       ;3.30
+	mov	bx, CntryFileHandle					       ;3.30
+	mov	ah, 3eh 						       ;3.30
+	int	21h			;close a file. Don't care even if it fa;3.30ils.
+	JMP	COFF							       ;3.30
+
+;------------------------------------------------------------------------------
+; Files command
+;------------------------------------------------------------------------------
+TRYF:
+	CMP	AH,'F'
+	JNZ	TRYL
+	invoke	GETNUM
+	CMP	AX,5
+	JB	TryFBad 		; Gotta have at least 5
+	CMP	AX,256
+	JAE	TryFBad 		; Has to be a byte
+	MOV	[FILES],AL
+CoffJ5: JMP	COFF
+TryFBad:JMP	BadOp
+;------------------------------------------------------------------------------
+; LastDrive command
+;------------------------------------------------------------------------------
+TRYL:
+	CMP	AH,'L'
+	JNZ	TRYP
+	OR	AL,020h
+	SUB	AL,'a'
+	JB	TryLBad
+	INC	AL
+	CMP	AL,26			; a-z are allowed
+	JA	TryLBad
+	MOV	[NUM_CDS],AL
+CoffJ6: JMP	COFF
+TryLBad:JMP	BadOp
+;-------------------------------------------------------------------------------
+; Setting Drive Parameters
+;-------------------------------------------------------------------------------
+TRYP:
+	CMP	AH,'P'
+	JNZ	TRYK
+	invoke	PARSELINE
+	JC	TryLBad
+	invoke	SETPARMS
+	INVOKE	DIDDLEBACK
+	jc	TryLBad
+	JMP	COFF
+;-------------------------------------------------------------------------------
+; Setting Internal Stack Parameters
+; STACK=M,N where
+;	M is the number of stacks (range 8 to 64, default 9)
+;	N is the stack size (range 32 to 512 bytes, default 128)
+;  5/5/86: STACKS=0,0 implies no stack installation.		  ;3.30
+;	Any combinations that are not within the specified limits will	  ;3.30
+;	result in "Unrecognized command" error.                           ;3.30
+;-------------------------------------------------------------------------------
+TRYK:
+	CMP	AH,'K'
+	JNZ	TRYW
+
+		IF	STACKSW 					  ;3.30
+
+	MOV	SepChr,','
+	INVOKE	GetNum			; Get number of stacks
+	MOV	SepChr,0
+	cmp	ax, 0			; 5/5/86			  ;3.30
+	je	TRYK_0			; Let's accept 0.             ;3.30
+	CMP	AX, MinCount		; 8 <= Number of Stacks <= 64
+	JB	TryKBad
+	CMP	AX, MaxCount
+	JA	TryKBad
+TRYK_0: 								  ;3.30
+	MOV	[STACK_COUNT], AX
+;
+; Skip delimiters after the ,
+;
+	invoke	Skip_delim		;				  ;3.30
+	JC	TryKBad
+
+	INVOKE	GetNum			; Get size of individual stack
+	JC	TryKBad 		; Number bad
+
+	cmp	ax, 0			; 5/5/86			  ;3.30
+	je	TRYK_SIZE0		; 5/5/86. Accept 0		  ;3.30
+
+	CMP	AX, MinSize		; 32 <= Stack Size <= 512
+	JB	TryKBad
+	CMP	AX, MaxSize
+	JA	TryKBad
+TRYK_SIZE0:								  ;3.30
+	MOV	[STACK_SIZE], AX
+	cmp	ax,0							  ;3.30
+	je	TRYK_BOTH0						  ;3.30
+TRYK_OK:								  ;3.30
+	mov	word ptr [stack_addr], -1 ;set flag. user entered stacks= ;3.30
+	JMP	COFF
+TRYK_BOTH0:								  ;3.30
+	cmp	[STACK_COUNT],0 	;stack_size=0. Stack_Count=0 too? ;3.30
+	je	TRYK_OK 		;yes. accepted. 		  ;3.30
+TryKBad:
+	MOV	DX, OFFSET BADSTACK	; 5/26/86 "Invalid stack parameter";3.30
+	invoke	PRINT							  ;3.30
+	JMP	COFF							  ;3.30
+
+		ENDIF							  ;3.30
+;------------------------------------------------------------------------------
+; Switch command
+;------------------------------------------------------------------------------
+TRYW:
+	CMP	AH,'W'
+	JNZ	TRYA
+	JMP	BadOp			; no longer implemented
+;	MOV	DL,AL
+;	MOV	AX,(CHAR_OPER SHL 8) OR 1      ;SET SWITCH CHARACTER
+;	MOV	[COMMAND_LINE+1],DL
+;	INT	21H
+;	JMP	COFF
+
+;------------------------------------------------------------------------------
+; Availdev command
+;------------------------------------------------------------------------------
+TRYA:
+	CMP	AH,'A'
+	JNZ	TRYS
+	JMP	BadOp			; NO LONGER IMPLEMENTED
+;	CMP	AL,'F'                  ;FIRST LETTER OF "FALSE"
+;	JNZ	COFFJ7
+;	MOV	AX,(CHAR_OPER SHL 8) OR 3 ;TURN ON "/DEV" PREFIX
+;	XOR	DL,DL
+;	INT	21H
+;COFFJ7: JMP	 COFF
+
+;------------------------------------------------------------------------------
+; shell command
+;------------------------------------------------------------------------------
+TRYS:
+	CMP	AH,'S'
+	JNZ	TRYX
+	MOV	[COMMAND_LINE+1],0
+	MOV	DI,OFFSET COMMND + 1
+	MOV	[DI-1],AL
+STORESHELL:
+	CALL	GETCHR
+	OR	AL,AL
+	JZ	GETSHPARMS
+	CMP	AL," "
+	JB	ENDSH
+	MOV	[DI],AL
+	INC	DI
+	JMP	STORESHELL
+
+ENDSH:
+	MOV	BYTE PTR [DI],0
+	CALL	GETCHR
+	CMP	AL,10
+	JNZ	CONV
+	CALL	GETCHR
+CONV:	JMP	CONFLP
+
+;------------------------------------------------------------------------------
+; FCBS Command
+;------------------------------------------------------------------------------
+TRYX:
+	CMP	AH,'X'
+	JNZ	TRYZ
+	invoke	GETNUM
+	JZ	TryXBad 		; gotta have at least one
+	CMP	AX,256
+	JAE	TryXBad 		; Can't be more than 8 bits worth
+	MOV	[FCBS],AL
+;
+; Skip delimiters after the ,
+;
+	invoke	Skip_delim		;				  ;3.30
+	jc	tryxbad
+	invoke	GetNum
+	JC	TryXBad 		; Number bad (Zero is OK here)
+	CMP	AX,256
+	JAE	TryXBad
+	CMP	AL,FCBS
+	JA	TryXBad
+	MOV	Keep,AL
+	JMP	COFF
+TryXBad:JMP	BadOp
+
+;------------------------------------------------------------------------------
+; Bogus command
+;------------------------------------------------------------------------------
+TRYZ:
+	JMP	BADOP
+
+GETSHPARMS:
+	MOV	BYTE PTR [DI],0
+	MOV	DI,OFFSET COMMAND_LINE+1
+PARMLOOP:
+	CALL	GETCHR
+	CMP	AL," "
+	JB	ENDSH
+	MOV	[DI],AL
+	INC	DI
+	JMP	PARMLOOP
+
+GETCHR:
+	PUSH	CX
+	MOV	CX,COUNT
+	JCXZ	NOCHAR
+	MOV	SI,CHRPTR
+	MOV	AL,ES:[SI]
+	DEC	COUNT
+	INC	CHRPTR
+	CLC
+GET_RET:
+	POP	CX
+	return
+NOCHAR: STC
+	JMP	SHORT GET_RET
+
+
+SYSINITSEG	ENDS
+	END
+

SRC/BIOS/SYSIMES.ASM

@@ -0,0 +1,18 @@
+TEST = 0								  ;3.30
+include msequ.inc							  ;3.30
+include msmacro.inc							  ;3.30
+									  ;3.30
+SYSINITSEG	SEGMENT PUBLIC BYTE 'SYSTEM_INIT'                         ;3.30
+									  ;3.30
+	PUBLIC	BADOPM,CRLFM,BADSIZ_PRE,BADLD_PRE,BADCOM,SYSSIZE,BADCOUNTRY ;3.30
+	PUBLIC	BADLD_POST,BADSIZ_POST,BADMEM,BADBLOCK,BADSTACK 	  ;3.30
+	PUBLIC	INSUFMEMORY,BADCOUNTRYCOM				  ;3.30
+									  ;3.30
+include sysimes.inc							  ;3.30
+									  ;3.30
+SYSSIZE LABEL	BYTE							  ;3.30
+									  ;3.30
+PATHEND 	001,SYSMES						  ;3.30
+									  ;3.30
+SYSINITSEG	ENDS							  ;3.30
+	END								  ;3.30

SRC/BIOS/SYSIMES.INC

@@ -0,0 +1,68 @@
+
+;
+; printed when there is a bad command in CONFIG.SYS. '$' TERMINATED, note
+;   that this message includes crlfm.
+;
+
+PATHSTART	001,SYSMES						  ;3.30
+BADOPM	DB	13,10,"Unrecognized command in CONFIG.SYS"
+
+BADSIZ_POST LABEL   BYTE
+BADLD_POST  LABEL   BYTE
+CRLFM	DB	13,10,'$'
+
+
+;
+;PRINTED when installed device specifies too large a sector size.'$' terminated.
+; FORM: 	<BADSIZ_PRE>device name<BADSIZ_POST>
+;
+
+BADSIZ_PRE  DB	    13,10,"Sector size too large in file $"
+
+;
+;PRINTED when installed device cannot be found. '$' terminated.
+; FORM: 	<BADLD_PRE>device name<BADLD_POST>
+;
+
+BADLD_PRE   DB	    13,10,"Bad or missing $"
+
+;
+;PRINTED when command interpreter is not found. NUL terminated.
+; FORM: 	<BADLD_PRE><BADCOM><BADLD_POST>
+;
+
+BADCOM	DB	"Command Interpreter",0
+
+;PRINTED when country code, code page combination was not found 	  ;3.30
+;  in country.sys file. '$' terminated.                                   ;3.30
+; FORM: 	<BADCOUNTRY>						  ;3.30
+BADCOUNTRY DB	13,10,"Invalid country code or code page",13,10,"$"       ;3.30
+									  ;3.30
+;PRINTED when code page id is missing or wrong syntax. - J.K.		  ;3.30
+; FORM: 	<BADCOUNTRYCOM> 					  ;3.30
+BADCOUNTRYCOM DB 13,10,"Error in COUNTRY command",13,10,"$"               ;3.30
+									  ;3.30
+;PRINTED when the memory left is not sufficient to handle COUTRY.SYS file ;3.30
+; FORM: 	<INSUFMEMORY>						  ;3.30
+INSUFMEMORY DB 13,10, "Insufficient memory for COUNTRY.SYS file",13,10,"$" ;3.30
+									  ;3.30
+;
+; PRINTED when there is insufficient memory. '$' TERMINATED, note
+;   that this message includes crlfm!
+;
+
+BADMEM	DB	13,10,"Configuration too large for memory",13,10,"$"
+
+;
+; PRINTED when the attempt is made to install a block device which would
+;   have a drive letter > 'Z'
+;
+
+BADBLOCK DB	13,10,"Too many Block Devices",13,10,"$"
+
+
+; PRINTED when the attempt is made to install a stack with invalid	  ;3.30
+;   combinations of # of stacks, stack size.	- J.K. 5/23/86		  ;3.30
+BADSTACK DB	13,10,"Invalid STACK parameters",13,10,"$"                ;3.30
+									  ;3.30
+

SRC/BOOT/BOOT11.INC

@@ -0,0 +1,64 @@
+	db	0EBH,027H,090H,008H,000H,014H,000H,000H
+	db	000H,000H,000H,000H,000H,000H,000H,000H
+	db	000H,000H,000H,000H,000H,000H,000H,000H
+	db	000H,000H,000H,000H,000H,000H,000H,000H
+	db	000H,000H,000H,000H,000H,000H,000H,0CDH
+	db	019H,0FAH,08CH,0C8H,08EH,0D8H,033H,0D2H
+	db	08EH,0D2H,0BCH,000H,07CH,0FBH,0B8H,060H
+	db	000H,08EH,0D8H,08EH,0C0H,033H,0D2H,08BH
+	db	0C2H,0CDH,013H,072H,069H,0E8H,085H,000H
+	db	072H,0DDH,02EH,083H,03EH,003H,07CH,008H
+	db	074H,006H,02EH,0C6H,006H,064H,07DH,002H
+	db	0BBH,000H,000H,02EH,08BH,00EH,003H,07CH
+	db	051H,0B0H,009H,02AH,0C1H,0B4H,000H,08BH
+	db	0F0H,056H,033H,0D2H,033H,0C0H,08AH,0C5H
+	db	02EH,0F6H,036H,064H,07DH,08AH,0E8H,08AH
+	db	0F4H,08BH,0C6H,0B4H,002H,0CDH,013H,072H
+	db	02DH,05EH,059H,02EH,029H,036H,005H,07CH
+	db	074H,01FH,08BH,0C6H,02EH,0F7H,026H,065H
+	db	07DH,003H,0D8H,0FEH,0C5H,0B1H,001H,051H
+	db	0BEH,008H,000H,02EH,03BH,036H,005H,07CH
+	db	07CH,005H,02EH,08BH,036H,005H,07CH,0EBH
+	db	0C0H,0EAH,000H,000H,060H,000H,0BEH,067H
+	db	07DH,0E8H,002H,000H,0EBH,0FEH,032H,0FFH
+	db	02EH,0ACH,024H,07FH,074H,00BH,056H,0B4H
+	db	00EH,0BBH,007H,000H,0CDH,010H,05EH,0EBH
+	db	0EFH,0C3H,0E9H,033H,0FFH,0BBH,000H,000H
+	db	0B9H,004H,000H,0B8H,001H,002H,0CDH,013H
+	db	01EH,072H,033H,08CH,0C8H,08EH,0D8H,0BFH
+	db	000H,000H,0B9H,00BH,000H,026H,080H,00DH
+	db	020H,026H,080H,04DH,020H,020H,047H,0E2H
+	db	0F4H,0BFH,000H,000H,0BEH,08BH,07DH,0B9H
+	db	00BH,000H,0FCH,0F3H,0A6H,075H,00FH,0BFH
+	db	020H,000H,0BEH,097H,07DH,0B9H,00BH,000H
+	db	0F3H,0A6H,075H,002H,01FH,0C3H,0BEH,01BH
+	db	07DH,0E8H,0A2H,0FFH,0B4H,000H,0CDH,016H
+	db	01FH,0F9H,0C3H,00DH,00AH,04EH,06FH,06EH
+	db	02DH,053H,079H,073H,074H,065H,06DH,020H
+	db	064H,069H,073H,06BH,020H,06FH,072H,020H
+	db	064H,069H,073H,06BH,020H,065H,072H,072H
+	db	06FH,072H,00DH,00AH,052H,065H,070H,06CH
+	db	061H,063H,065H,020H,061H,06EH,064H,020H
+	db	073H,074H,072H,069H,06BH,065H,020H,061H
+	db	06EH,079H,020H,06BH,065H,079H,020H,077H
+	db	068H,065H,06EH,020H,072H,065H,061H,064H
+	db	079H,00DH,00AH,000H,001H,000H,002H,00DH
+	db	00AH,044H,069H,073H,06BH,020H,042H,06FH
+	db	06FH,074H,020H,066H,061H,069H,06CH,075H
+	db	072H,065H,00DH,00AH,000H,04DH,069H,063H
+	db	072H,06FH,073H,06FH,066H,074H,02CH,049H
+	db	06EH,063H,020H,069H,06FH,020H,020H,020H
+	db	020H,020H,020H,073H,079H,073H,030H,06DH
+	db	073H,064H,06FH,073H,020H,020H,020H,073H
+	db	079H,073H,030H,005H,0C6H,006H,077H,02FH
+	db	0FFH,083H,07EH,0FCH,000H,075H,00BH,080H
+	db	07EH,0F7H,03BH,075H,005H,0C6H,006H,076H
+	db	02FH,0FFH,089H,0ECH,05DH,0CAH,004H,000H
+	db	000H,000H,000H,000H,000H,000H,000H,000H
+	db	000H,000H,000H,000H,000H,000H,000H,000H
+	db	000H,000H,000H,000H,000H,000H,000H,000H
+	db	000H,000H,000H,000H,000H,000H,000H,000H
+	db	000H,000H,000H,000H,000H,000H,000H,000H
+	db	000H,000H,000H,000H,000H,000H,000H,000H
+	db	000H,000H,000H,000H,000H,000H,000H,000H
+	db	000H,000H,000H,000H,000H,000H,000H,000H

SRC/BOOT/MAKEFILE

@@ -0,0 +1,38 @@
+#**     makefile for Boot
+
+DEST	= msboot
+MSG	= messages
+
+#	Path definitions
+
+BIOS	= ..\..\BIOS
+DOS	= ..\..\DOS
+
+#       Definitions for assembler
+
+ASM	= masm
+AFLAGS	= -Mx -t
+AINC	= -I..\..\inc
+
+#       Definitions for C compiler
+
+CC	= cl
+CFLAGS	= -Ox -Zlp
+CINC	= -I..\..\h
+
+#	Definitions for linker
+
+LINK	= link
+LIBC	= ..\..\libc
+
+
+# Rules and Dependencies follow
+
+msboot.obj: msboot.asm $(MSG).inc
+	masm $(AFLAGS) $(AINC) msboot;
+
+msboot.bin: msboot.obj
+	LINK msboot;
+	EXE2BIN msboot.exe msboot.bin
+	DEL msboot.exe
+	DBOF msboot.bin boot.inc 7C00 200

SRC/BOOT/MESSAGES.INC

@@ -0,0 +1,7 @@
+;	SCCSID = @(#)messages.inc	1.1 85/05/13
+; MESSAGES FOR THE BOOT SECTOR. NUL Terminated.
+
+SYSMSG  DB      13,10,"Non-System disk or disk error"
+        DB      13,10,"Replace and strike any key when ready",13,10,0
+
+DMSSG   DB      13,10,"Disk Boot failure",13,10,0

SRC/BOOT/MSBOOT.ASM

@@ -0,0 +1,386 @@
+;	SCCSID = @(#)ibmboot.asm	1.1 85/05/13
+TITLE BOOT	SECTOR 1 OF TRACK 0 - BOOT LOADER
+
+;   Rev 1.0 ChrisP, AaronR and others.	2.0 format boot
+;
+;   Rev 3.0 MarkZ   Salmon enhancements
+;		    2.50 in label
+;   Rev 3.1 MarkZ   3.1 in label due to vagaries of SYSing to IBM drive D's
+;		    This resulted in the BPB being off by 1.  So we now trust
+;		    2.0 and 3.1 boot sectors and disbelieve 3.0.
+;
+;   Rev 3.2 LeeAc   Modify layout of extended BPB for >32M support
+;		    Move PHYDRV to 3rd byte from end of sector
+;		    so that it won't have to be moved again
+;		    FORMAT and SYS count on PHYDRV being in a known location
+;
+;   Rev. 3.3 DCLove Changed Sec 9 EOT field from 15 to 18. May 29, 1986.
+;
+;   Rev 3.31 MarkT  The COUNT value has a bogus check (JBE????) to determine
+;		    if we've loaded in all the sectors of IO.SYS. This will
+;		    cause too big of a load if the sectors per track is high
+;		    enough, causing either a stack overflow or the boot code
+;		    to be overwritten.
+;
+;
+; The ROM in the IBM PC starts the boot process by performing a hardware
+; initialization and a verification of all external devices.  If all goes
+; well, it will then load from the boot drive the sector from track 0, head 0,
+; sector 1.  This sector is placed at physical address 07C00h.	The initial
+; registers are set up as follows:  CS=DS=ES=SS=0.  IP=7C00h, SP=0400H.
+;
+; The code in this sector is responsible for locating the MSDOS device drivers
+; (IO.SYS) and for placing the directory sector with this information at
+; physical address 00500h.  After loading in this sector, it reads in the
+; entirety of the BIOS at BIOSEG:0 and does a long jump to that point.
+;
+; If no BIOS/DOS pair is found an error message is displayed and the user is
+; prompted to reinsert another disk.  If there is a disk error during the
+; process, a message is displayed and things are halted.
+;
+; At the beginning of the boot sector, there is a table which describes the
+; MSDOS structure of the media.  This is equivalent to the BPB with some
+; additional information describing the physical layout of the driver (heads,
+; tracks, sectors)
+;
+
+ORIGIN	    EQU 7C00H			; Origin of bootstrap LOADER
+BIOSEG	    EQU 70H			; destingation segment of BIOS
+BioOff	    EQU 700H			; offset of bios
+cbSec	    EQU 512
+cbDirEnt    EQU 32
+DirOff	    EQU 500h
+
+;
+; Define the destination segment of the BIOS, including the initialization
+; label
+;
+SEGBIOS SEGMENT AT BIOSEG
+BIOS	LABEL	BYTE
+SEGBIOS ENDS
+
+CODE	SEGMENT
+	ASSUME CS:CODE,DS:NOTHING,ES:NOTHING,SS:NOTHING
+	ORG	DirOff + 1Ch
+BiosFS	LABEL	WORD
+
+	ORG	ORIGIN
+
+DSKADR	=	1EH*4			;POINTER TO DRIVE PARAMETERS
+
+Public $START
+$START:
+	JMP	START
+;----------------------------------------------------------
+;
+;	THE FOLLOWING DATA CONFIGURES THE BOOT PROGRAM
+;	FOR ANY TYPE OF DRIVE OR HARDFILE
+;
+	DB	"MSDOS"
+	DB	"3.3"
+ByteSec DW	cbSec			; SIZE OF A PHYSICAL SECTOR
+	DB	8			; SECTORS PER ALLOCATION UNIT
+cSecRes DW	1			; NUMBER OF RESERVED SECTORS
+cFat	DB	2			; NUMBER OF FATS
+DirNum	DW	512			; NUMBER OF DIREC ENTRIES
+	DW	4*17*305-1		; NUMBER OF SECTORS - NUMBER OF HIDDEN SECTORS
+MEDIA	DB	0F8H			; MEDIA BYTE
+cSecFat DW	8			; NUMBER OF FAT SECTORS
+SECLIM	DW	17			; SECTORS PER TRACK
+HDLIM	DW	4			; NUMBER OF SURFACES
+cSecHid DW	1			; NUMBER OF HIDDEN SECTORS
+	dw	0			; high order word of Hiden Sectors
+	dd	0			; 32 bit version of NUMBER OF SECTORS
+					; (when 16 bit version is zero)
+	db	6 dup(?)		; reserved for later expansion
+
+
+CURHD	DB	?			; Unitialized
+
+; this is an image of the disk parameter table.  Zero entries are copied
+; from the rom table at boot.
+;
+SEC9	DB	0			;   DISK_SPECIFY_1
+	DB	0			;   DISK_SPECIFY_2
+	DB	0			;   DISK_MOTOR_WAIT
+	DB	0			;   DISK_SECTOR_SIZ
+	DB	12h			;   DISK_EOT
+	DB	0			;   DISK_RW_GAP
+	DB	0			;   DISK_DTL
+	DB	0			;   DISK_FORMT_GAP
+	DB	0			;   DISK_FILL
+	DB	1			;   DISK_HEAD_STTL
+	DB	0			;   DISK_MOTOR_STRT
+
+Public UDATA
+UDATA	LABEL	WORD
+BIOS$	EQU	WORD PTR UDATA+1
+CURTRK	EQU	WORD PTR UDATA+3
+CURSEC	EQU	BYTE PTR UDATA+5
+COUNT	EQU	BYTE PTR UDATA+6	; NUMBER OF BIOS SECTORS
+BIOSAV	EQU	WORD PTR UDATA+7
+DIR$	EQU	WORD PTR UDATA+9
+
+START:
+
+;
+; First thing is to reset the stack to a better and more known place.  The ROM
+; may change, but we'd like to get the stack in the correct place.
+;
+	CLI				;Stop interrupts till stack ok
+	XOR	AX,AX
+	MOV	SS,AX			;Work in stack just below this routine
+	ASSUME	SS:CODE
+	MOV	SP,ORIGIN
+	PUSH	SS
+	POP	ES
+	ASSUME	ES:CODE
+;
+; We copy the disk parameter table into a local area.  We scan the table above
+; for non-zero parameters.  Any we see get changed to their non-zero values.
+;
+	MOV	BX,DSKADR
+	LDS	SI,DWORD PTR SS:[BX]	; get address of disk table
+	PUSH	DS			; save original vector for possible
+	PUSH	SI			; restore
+	PUSH	SS
+	PUSH	BX
+	MOV	DI,OFFSET Sec9
+	MOV	CX,11
+	CLD
+changeloop:
+	LODSB
+	CMP	BYTE PTR ES:[DI],0	; is the template zero?
+	JZ	Store			; yes, store what we've got
+	MOV	AL,ES:[DI]
+Store:
+	STOSB
+	MOV	AL,AH
+	LOOP	ChangeLoop
+;
+; Place in new disk parameter table.
+;
+	PUSH	ES
+	POP	DS
+	ASSUME	DS:CODE
+	MOV	[BX+2],AX
+	MOV	[BX],OFFSET SEC9
+;
+; We may now turn interrupts back on.  Before this, there is a small window
+; when a reboot command may come in when the disk parameter table is garbage
+;
+	STI				;Interrupts OK now
+;
+; Reset the disk system just in case any thing funny has happened.
+;
+	INT	13H			;Reset the system
+	JC	RERROR
+;
+; The system is now prepared for us to begin reading.  First, determine
+; logical sector numbers of the start of the directory and the start of the
+; data area.
+;
+	MOV	AL,cFat 	      ;Determine sector dir starts on
+	CBW
+	MUL	cSecFat
+	ADD	AX,cSecHid
+	ADD	AX,cSecRes
+	MOV	[DIR$],AX		; AX = cFat*cSecFat + cSecRes + cSecHid
+	MOV	[BIOS$],AX
+;
+; Take into account size of directory (only know number of directory entries)
+;
+	MOV	AX,cbDirEnt		; bytes per directory entry
+	MUL	DirNum			; convert to bytes in directory
+	MOV	BX,ByteSec		; add in sector size
+	ADD	AX,BX
+	DEC	AX			; decrement so that we round up
+	DIV	BX			; convert to sector number
+	ADD	[BIOS$],AX
+;
+; We load in the first directory sector and examine it to make sure the the
+; BIOS and DOS are the first two directory entries.  If they are not found,
+; the user is prompted to insert a new disk.  The directory sector is loaded
+; into 00500h
+;
+	MOV	BX,DirOff		; sector to go in at 00500h
+	MOV	AX,DIR$ 		; logical sector of directory
+	CALL	DODIV			; convert to sector, track, head
+	MOV	AX,0201H		; disk read 1 sector
+	CALL	DOCALL			; do the disk read
+	JB	CKERR			; if errors try to recover
+;
+; Now we scan for the presence of IO.SYS  and MSDOS.SYS. Check the
+; first directory entry.
+;
+	MOV	DI,BX
+	MOV	CX,11
+	MOV	SI,OFFSET BIO		; point to "bios     com"
+	REPZ	CMPSB			; see if the same
+	JNZ	CKERR			; if not there advise the user
+;
+; Found the BIOS.  Check the second directory entry.
+;
+	LEA	DI,[BX+20h]
+	MOV	SI,OFFSET DOS		; point to "86dos   com"
+	MOV	CX,11
+	REPZ	CMPSB
+	JZ	DoLoad
+;
+; There has been some recoverable error.  Display a message and wait for a
+; keystroke.
+;
+CKERR:	MOV	SI,OFFSET SYSMSG	; point to no system message
+ErrOut: CALL	WRITE			; and write on the screen
+	XOR	AH,AH			; wait for response
+	INT	16H			; get character from keyboard
+	POP	SI			; reset disk parameter table back to
+	POP	DS			; rom
+	POP	[SI]
+	POP	[SI+2]
+	INT	19h			; Continue in loop till good disk
+
+RERROR: MOV	SI,OFFSET DMSSG 	; DISK ERROR MESSAGE
+	JMP	ErrOut
+;
+; We now begin to load the BIOS in.  Compute the number of sectors needed
+;
+DoLoad:
+	MOV	AX,BiosFS		; get file size
+	XOR	DX,DX			; presume < 64K
+	DIV	ByteSec 		; convert to sectors
+	INC	AL			; reading in one more can't hurt
+	MOV	COUNT,AL		; Store running count
+	MOV	AX,BIOS$		; get logical sector of beginning of BIOS
+	MOV	BIOSAV,AX		; store away for real bios later
+	MOV	BX,BioOff		; Load address from BIOSSEG
+;
+; Main read-in loop.
+;   ES:BX points to area to read.
+;   Count is the number of sectors remaining.
+;   BIOS$ is the next logical sector number to read
+;
+LOOPRD:
+	MOV	AX,BIOS$		; Starting sector
+	CALL	DODIV
+;
+; CurHD is the head for this next disk request
+; CurTrk is the track for this next request
+; CurSec is the beginning sector number for this request
+;
+; Compute the number of sectors that we may be able to read in a single ROM
+; request.
+;
+	MOV	AX,SECLIM
+	SUB	AL,CURSEC
+	INC	AX
+;
+; AX is the number of sectors that we may read.
+;
+
+;
+;New code for Rev 3.31
+;*****************************************************************************
+
+	CMP	COUNT,AL	  ;Is sectors we can read more than we need?
+	JAE	GOT_SECTORS	  ;No, it is okay
+	MOV	AL,COUNT	  ;Yes, only read in what is left
+
+GOT_SECTORS:
+
+;*****************************************************************************
+;End of change
+;
+
+
+	PUSH	AX
+	CALL	DOCALL
+	POP	AX
+	JB	RERROR			; If errors report and go to ROM BASIC
+	SUB	COUNT,AL		; Are we finished?
+;
+;Old code replaced by Rev 3.3
+;********************************************************************
+;	JBE	DISKOK			; Yes -- transfer control to the DOS
+;********************************************************************
+;New code for Rev 3.3
+;
+
+	JZ	DISKOK			; Yes -- transfer control to the DOS
+
+;********************************************************************
+;End of change
+;
+	ADD	BIOS$,AX		; increment logical sector position
+	MUL	ByteSec 		; determine next offset for read
+	ADD	BX,AX			; (BX)=(BX)+(SI)*(Bytes per sector)
+	JMP	LOOPRD			; Get next track
+;
+; IBMINIT requires the following input conditions:
+;
+;   DL = INT 13 drive number we booted from
+;   CH = media byte
+;   BX = First data sector on disk (0-based)
+;
+DISKOK:
+	MOV	CH,Media
+	MOV	DL,PhyDrv
+	MOV	BX,[BIOSAV]		;Get bios sector in bx
+	JMP	FAR PTR BIOS		;CRANK UP THE DOS
+
+WRITE:	LODSB				;GET NEXT CHARACTER
+	OR	AL,AL			;clear the high bit
+	JZ	ENDWR			;ERROR MESSAGE UP, JUMP TO BASIC
+	MOV	AH,14			;WILL WRITE CHARACTER & ATTRIBUTE
+	MOV	BX,7			;ATTRIBUTE
+	INT	10H			;PRINT THE CHARACTER
+	JMP	WRITE
+;
+; convert a logical sector into Track/sector/head.  AX has the logical
+; sector number
+;
+DODIV:
+	XOR	DX,DX
+	DIV	SECLIM
+	INC	DL			; sector numbers are 1-based
+	MOV	CURSEC,DL
+	XOR	DX,DX
+	DIV	HDLIM
+	MOV	CURHD,DL
+	MOV	CURTRK,AX
+ENDWR:	RET
+;
+; Issue one read request.  ES:BX have the transfer address, AL is the number
+; of sectors.
+;
+DOCALL: MOV	AH,2
+	MOV	DX,CURTRK
+	MOV	CL,6
+	SHL	DH,CL
+	OR	DH,CURSEC
+	MOV	CX,DX
+	XCHG	CH,CL
+	MOV	DL, PHYDRV
+	mov	dh, curhd
+	INT	13H
+	RET
+
+	include messages.inc
+
+BIO	DB	"IO      SYS"
+DOS	DB	"MSDOS   SYS"
+
+Free	EQU (cbSec - 3) - ($-$start)
+if Free LT 0
+    %out FATAL PROBLEM:boot sector is too large
+endif
+
+	org	origin + (cbSec - 3)
+
+; FORMAT and SYS count on PHYDRV being right here
+PHYDRV	db	0
+; Boot sector signature
+	db	55h,0aah
+
+CODE	ENDS
+	END

SRC/BUGFIX/BIOS/MSBIO2.ASM

@@ -0,0 +1,650 @@
+	TITLE MSBIO2 - DOS 3.3
+
+;-------------------------------------------------------------------------------
+;									       :
+;			    Microsoft Bio				       :
+;									       :
+;  The file msbio.asm is the main file in the Mircosoft bio.  This file        :
+; includes the other main files in the bio.  Most of the routines are	       :
+; in these include files.  The main files included are: 		       :
+;									       :
+;	File		Contains					       :
+;									       :
+;	msdisk.inc	Disk device driver routines			       :
+;	ms96tpi.inc	Routines for 96tpi drives			       :
+;	msaux.inc	Device driver for the rs-232 serial ports	       :
+;	msclock.inc	Device driver for "clock$" device                      :
+;	mscon.inc	Device driver for "con"                                :
+;	mslpt.inc	Device driver for the printers			       :
+;									       :
+;  Each of these files contain a header section documenting the code	       :
+;  in that file.							       :
+;    Msbio also includes several files for equ's, structure definition,        :
+;  macro definitions, etc.  These are:					       :
+;									       :
+;	msbiomes.inc	 msmacro.inc	devsym.inc			       :
+;		dskprm.inc	   error.inc				       :
+;									       :
+;  Each of these file contains explanitory notes.			       :
+;									       :
+;    The actual code in msbio can be broken down into several piece:	       :
+;									       :
+;	macro definitions	Several marco are defined in msbio.  They      :
+;				are a few odds and end that did not fit        :
+;				anywhere else.				       :
+;									       :
+;	Command Jump Table	List of entry points in the device drivers.    :
+;				See notation below for full explination.       :
+;									       :
+;	Interrupt and Strategy						       :
+;	  Entry points		Calls on the device driver first come to here. :
+;				There is common code with pushes registers and :
+;				the like before jumping to routines in the     :
+;				driver files.  The common exit points are also :
+;				in this file.				       :
+;									       :
+;	Miscellaneous Code	There are several routines and data structure  :
+;				declarations.  See below for details.	       :
+;									       :
+;-------------------------------------------------------------------------------
+
+
+
+;
+; If the variable TEST is non-zero then code for debugging is included.
+; The extra code will make the binary file nuch larger.
+; The symbol is also defined in msequ.inc.  Both must be changed to
+; turn debugging on or off.
+;
+; The level of the debugging is controled by the variable fTestBits in
+; this file.  See the comment preceeding the variable for more information.
+; The actual routines which print the messages are in msmacro.inc
+; See the header comment in this file for more information.
+;
+
+
+;
+; Revision History
+;
+;   REV 2.1	5/1/83 ARR added timer int handler and changed order of AUX
+;		    PRN init for HAL0
+;
+;   REV 2.15	7/13/83 ARR Because of IBM design issues, and that BASCOM
+;		    is ill behaved with respect to the 1CH timer interrupt,
+;		    the timer handler has to be backed out! The intended
+;		    code is commented out and has an ARR 2.15 annotation.
+;		    This means the BIOS will go back to the multiple roll
+;		    over bug.
+;
+;   REV 2.20	8/5/83 ARR IBM makes hardware change.  Now wants to use half
+;		    height drives for HAL0, and back fit for PC/PC XT.	Problem
+;		    with head settle time.  Previous drives got by on a 0
+;		    settle time, 1/2 hight drives need 15 head settle when
+;		    doing WRITEs (0 ok on READ) if the head is being stepped.
+;		    This requires a last track value to be kept so that BIOS
+;		    knows when head is being moved.  To help out
+;		    programs that issue INT 13H directly, the head settle will
+;		    normally be set to 15.  It will be changed to 0 on READs,
+;		    or on WRITEs which do not require head step.
+;
+;   REV 2.21	8/11/83 MZ IBM wants write with verify to use head settle 0.
+;		    Use same trick as above.
+;
+;   REV 2.25	6/20/83 mjb001 added support for 96tpi and salmon
+;
+;   REV 2.30	6/27/83 mjb002 added real-time clock
+;
+;   REV 2.40	7/8/83 mjb003 added volume-id checking and int 2f macro
+;		    definitions push* and pop*
+;
+;   REV 2.41	7/12/83 ARR more 2.X enhancements.  Open/Close media change
+;
+;   REV 2.42	11/3/83 ARR more 2.X enhancements.  Disk OPEN/CLOSE, FORMAT
+;		    code and other misc hooked out to shrink BIOS.  Code for
+;		    Disk OPEN/CLOSE, FORMAT included only with 96tpi disks.
+;
+;   Rev   2.43	12/6/83 MZ Examine boot sectors on hard disks for 16-bit fat
+;		    check.  Examine large fat bit in BPB for walk of media for
+;		    DOS
+;
+;   Rev   2.44	12/9/83 ARR Change to error reporting on INT 17H
+;
+;   Rev   2.45	12/22/83 MZ Make head settle change only when disk parm is 0.
+
+;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+;
+;	IBM ADDRESSES FOR I/O
+;
+;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+
+;Below was moved from sysinit1
+ROMSEGMENT	EQU	0F000H
+MODELBYTE	EQU	DS:BYTE PTR [0FFFEH]
+MODELPCJR	EQU	0FDH
+
+	test=0
+;;Rev 3.30 modification ----------------------------
+	INCLUDE MSGROUP.INC	;DEFINE CODE SEGMENT
+	INCLUDE MSEQU.INC
+	INCLUDE DEVSYM.INC
+	INCLUDE PUSHPOP.INC
+	INCLUDE MSMACRO.INC
+
+	ASSUME	DS:NOTHING,ES:NOTHING
+
+	EXTRN	DSK$IN:NEAR
+	EXTRN	SETPTRSAV:NEAR
+	EXTRN	OUTCHR:NEAR
+	EXTRN	SETDRIVE:NEAR
+	EXTRN	FLUSH:NEAR
+	EXTRN	HARDERR:NEAR
+	EXTRN	HARDERR2:NEAR
+	EXTRN	MAPERROR:NEAR
+	EXTRN	GETBP:NEAR
+	EXTRN	CHECKSINGLE:NEAR
+	EXTRN	CHECK_TIME_OF_ACCESS:NEAR
+	EXTRN	EXIT:NEAR
+	EXTRN	HAS1:NEAR
+	EXTRN	HAS1_res:NEAR
+	EXTRN	READ_SECTOR:NEAR
+	EXTRN	INT_2F_13:FAR
+
+	EXTRN	OLD13:DWORD
+
+;DATA
+	EXTRN	PTRSAV:DWORD
+	EXTRN	START_BDS:WORD
+	EXTRN	FDRIVE1:WORD
+	EXTRN	FDRIVE2:WORD
+	EXTRN	FDRIVE3:WORD
+	EXTRN	FDRIVE4:WORD
+	EXTRN	FLAGBITS:WORD
+	EXTRN	TIM_DRV:BYTE
+	EXTRN	MEDBYT:BYTE
+	EXTRN	DRVMAX:BYTE
+
+	PATHSTART 005,DISK
+	EVENB
+	PUBLIC	ORIG19
+ORIG19	DD	?
+
+	PUBLIC	INT19SEM
+INT19SEM DB	0			; INDICATE THAT ALL INT 19
+					; INITIALIZATION IS COMPLETE
+
+	IRP	AA,<02,08,09,0A,0B,0C,0D,0E,70,72,73,74,76,77>
+	public	Int19OLD&AA
+Int19OLD&AA	dd	-1		;Orignal hw int. vec for INT 19h.
+	ENDM
+
+	EVENB
+	PUBLIC	DSKDRVS
+DSKDRVS DW	FDRIVE1
+	DW	FDRIVE2
+	DW	FDRIVE3
+	DW	FDRIVE4
+	PUBLIC	HDSKTAB
+HDSKTAB DW	HDRIVE
+	DW	DRIVEX
+;* Next area is reseved for mini disk BPB pointers *** 4/7/86
+;* Don't change this pos. Should be add. from DskDrvs *** 4/7/86
+MINI_DISK_BPB_PTRS DB 40 dup (?)   ;4/7/86 - mem res for Mini disk.
+
+	EVENB
+	PUBLIC	INT_2F_NEXT
+INT_2F_NEXT DD	   ?
+
+RET_ADDR    DD	   ?
+
+	PATHEND 005,DISK
+;;End of modification ----------------------------
+
+;  INT19
+;
+;	We "hook" the INT_REBOOT vector, because contrary to IBM documentation,
+;  it does NOT "bootstrap" the machine.  It leaves memory almost untouched.
+;  Since the BIOS_INIT code assumes that certain Interrupt Vectors point to
+;  the ROM_BIOS  we must "unhook" them before issuing the actual INT_REBOOT.
+;  Currently the following vectors need to be unhooked:
+;		  02,08,09,0A,0B,0C,0D,0E,70,72,73,74,75,76,77
+;
+
+Public Int19
+Int19	proc	FAR
+	xor	AX,AX			; get data segment to
+	mov	DS,AX			;   point to the vector table
+	assume	ds:nothing
+	assume	es:nothing
+	les	DI,Old13		; get ES to point to this segment
+	mov	DS:[13h*4],DI		; restore old int13 value
+	mov	DS:[13h*4+2],ES
+
+	cmp	Byte ptr Int19Sem, 0
+	jnz	int19vecs
+	jmp	doint19
+
+;;Dos 3.30 Will not support the PC-Jr
+;;Rev 3.30 modification ----------------------------
+;	ON THE PCJR, DON'T REPLACE ANY VECTORS
+;	MODEL BYTE DEFINITIONS FROM MSSTACK.ASM
+;	MOV	AX,ROMSEGMENT
+;	MOV	DS,AX
+;	MOV	AL,MODELPCJR
+;
+;	CMP	AL,MODELBYTE
+;	JNE	INT19VECS
+;	JMP	DOINT19
+
+
+;Stacks code has changed these hardware interrupt vectors
+;STKINIT in SYSINIT1 will initialzie Int19hOLDxx values.
+int19vecs:
+
+;
+; we now need to unhook all the vector replace to prevent stack overflow
+;
+
+;;Rev 3.30 modification ----------------------------
+	XOR	AX,AX
+	MOV	DS,AX
+
+	IRP	AA,<02,08,09,0A,0B,0C,0D,0E,70,72,73,74,76,77>
+
+	LES	DI,Int19OLD&AA
+
+	mov	ax,es		; Put segment where we can compare it
+	cmp	ax,-1		; OPT 0ffffh is not likely
+	je	skip_int&AA	; OPT could get away without checking
+	cmp	di,-1		; OPT offset here.
+	je	skip_int&AA
+
+	MOV	DS:[AA&H*4],DI
+	MOV	DS:[AA&H*4+2],ES
+skip_int&AA:
+	ENDM
+;;End of modification ----------------------------
+
+doint19:
+	LES	DI,Orig19
+	MOV	DS:[19h*4],DI
+	MOV	DS:[19h*4+2],ES
+
+	INT	19h
+INT19	ENDP
+ASSUME	DS:CODE
+
+;*****************************************************************************
+PUBLIC	DSK$INIT
+DSK$INIT PROC	NEAR
+	PUSH	CS
+	POP	DS
+	MOV	AH,BYTE PTR DRVMAX
+	MOV	DI,OFFSET DskDrvs
+	JMP	SetPTRSAV
+DSK$INIT ENDP
+
+
+;
+; Int 2f handler for external block drivers to communicate with the internal
+; block driver in msdisk. The multiplex number chosen is 8. The handler
+; sets up the pointer to the request packet in [PTRSAV] and then jumps to
+; DSK$IN, the entry point for all disk requests.
+; On exit from this driver (at EXIT), we will return to the external driver
+; that issued this Int 2F, and can then remove the flags from the stack.
+; This scheme allows us to have a small external device driver, and makes
+; the maintainance of the various drivers (DRIVER and msBIO) much easier,
+; since we only need to make changes in one place (most of the time).
+;
+; AL contains the Int2F function:
+;   0 - Check for installed handler - RESERVED
+;   1 - Install the BDS into the linked list
+;   2 - DOS request
+;
+
+MYNUM		EQU	8
+
+Public Int2F_Disk
+Int2F_Disk PROC FAR
+	cmp	ah,MYNUM
+	je	Mine
+	jmp	cs:[Int_2F_Next]	; chain to next Int 2F handler
+Mine:
+	cmp	al,0F8H 		; IRET on reserved functions
+	jb	Do_Func
+	IRET
+Do_Func:
+	or	al,al			; A GET INSTALLED STATE request?
+	jne	Disp_Func
+	mov	al,0FFH
+	IRET
+Disp_Func:
+	Message fTestInit,<"Int2F_disk",cr,lf>
+	cmp	al,1			 ; Request for installing BDS?
+	jne	Do_DOS_Req
+	call	Install_BDS
+	IRET
+
+Do_DOS_Req:
+; Set up pointer to request packet
+	MOV	WORD PTR CS:[PTRSAV],BX
+	MOV	WORD PTR CS:[PTRSAV+2],ES
+	jmp	DSK$IN
+
+Int2F_Disk ENDP
+
+;
+; Install_BDS installs a BDS a location DS:DI into the current linked list of
+; BDS maintained by this device driver. It places the BDS at the END of the
+; list.
+Public Install_BDS
+INSTALL_BDS PROC NEAR
+	message ftestinit,<"Install BDS",cr,lf>
+; ds:di point to BDS to be installed
+	les	si,dword ptr cs:[Start_BDS] ; Start at beginning of list
+	push	es			    ; Save pointer to current BDS
+	push	si
+; es:si now point to BDS in linked list
+Loop_Next_BDS:
+	cmp	si,-1			    ; got to end of linked list?
+	jz	Install_Ret
+; If we have several logical drives using the same physical drive, we must
+; set the I_Am_Mult flag in each of the appropriate BDSs.
+	mov	al,byte ptr ds:[di].DriveNum
+	cmp	byte ptr es:[si].DriveNum,al
+	jnz	Next_BDS
+	message ftestinit,<"Logical Drives",cr,lf>
+	xor	bx,bx
+	mov	bl,fI_Am_Mult
+	or	word ptr ds:[di].flags,bx    ; set flags in both BDSs concerned
+	or	word ptr es:[si].flags,bx
+	mov	bl,fI_Own_Physical
+	xor	bx,-1
+	and	word ptr ds:[di].flags,bx   ; reset that flag for 'new' BDS
+; We must also set the fChangeline bit correctly.
+	mov	bx,word ptr es:[si].flags   ; determine if changeline available
+	and	bl,fChangeline
+	xor	bh,bh
+	or	word ptr ds:[di].flags,bx
+
+Next_BDS:
+; Before moving to next BDS, preserve pointer to current one. This is needed at
+; the end when the new BDS is linked into the list.
+	pop	bx			    ; discard previous pointer to BDS
+	pop	bx
+	push	es
+	push	si
+	mov	bx,word ptr es:[si].link + 2
+	mov	si,word ptr es:[si].link
+	mov	es,bx
+	jmp	short Loop_Next_BDS
+
+Install_Ret:
+	pop	si				; Retrieve pointer to last BDS
+	pop	es				; in linked list.
+	mov	ax,ds
+	mov	word ptr es:[si].link+2,ax	; install BDS
+	mov	word ptr es:[si].link,di
+	mov	word ptr ds:[di].link,-1	; set NEXT pointer to NULL
+	RET
+INSTALL_BDS ENDP
+
+;
+; RE_INIT installs the Int 2F vector that will handle communication between
+; external block drivers and the internal driver. It also installs the
+; Reset_Int_13 interface.  It is called by SYSYINIT
+;
+PUBLIC	RE_INIT
+RE_INIT PROC FAR
+	Message ftestinit,<"REINIT",CR,LF>
+	PUSH	AX
+	PUSH	DS
+	PUSH	DI
+	XOR	DI,DI
+	MOV	DS,DI
+	MOV	DI,2FH*4	    ; point it to Int 2F Vector
+	MOV	AX,WORD PTR DS:[DI]
+	MOV	WORD PTR CS:[INT_2F_NEXT],AX
+	MOV	AX,WORD PTR DS:[DI+2]		   ; preserve old Int 2F vector
+	MOV	WORD PTR CS:[INT_2F_NEXT+2],AX
+
+; INSTALL the Reset_Int_13
+; interface
+
+
+	CLI
+	MOV	Word Ptr DS:[DI],Offset Int_2f_13	  ; install new vectors
+	MOV	Word Ptr DS:[DI+2],CS
+	STI
+	POP	DI
+	POP	DS
+	POP	AX
+	RET
+
+RE_INIT ENDP
+
+;-------------------------------------------------
+;
+;  Ask to swap the disk in drive A:
+; Using a different drive in a one drive system so
+; request the user to change disks
+;
+Public SWPDSK
+SWPDSK	PROC	NEAR
+	mov	al,byte ptr ds:[di].drivelet	; get the drive letter
+	add	al,"A"
+	mov	cs:DRVLET,AL
+	push	ds			; preserve segment register
+	push	cs
+	pop	ds
+	mov	SI,OFFSET SNGMSG	; ds:si -> message
+	push	BX
+	call	WRMSG			;Print disk change message
+	call	FLUSH
+					; wait for a keyboard character
+	xor	AH, AH			; set command to read character
+	int	16h			; call rom-bios
+	POP	BX
+	pop	ds			; restore segment register
+WRMRET:
+	ret
+SWPDSK	ENDP
+
+;----------------------------------------------
+;
+;  WrMsg writes out message pointed to by [SI]
+;
+Public WrMsg
+WRMSG	PROC	NEAR
+	lodsb				; get the next character of the message
+	or	AL,AL			; see fi end of message
+	jz	WRMRET
+	pushf
+	push	CS
+	call	OUTCHR
+	jmp	SHORT WRMSG
+WRMSG	ENDP
+
+	INCLUDE BIOMES.INC
+
+;
+; End of support for multiple floppies with no logical drives
+; This is not 'special' any more because we now have the capability of
+; defining logical drives in CONFIG.SYS. We therefore keep the code for
+; swapping resident ALL the time.
+;
+
+;;Rev 3.30 modification ----------------------------
+;Variables for Dynamic Relocatable modules
+;These should be stay resident.
+
+	public	INT6C_RET_ADDR
+INT6C_RET_ADDR	DD	?		;ret add from INT 6C for P12 mach
+
+	PATHSTART 001,CLK
+;
+;   DATA STRUCTURES FOR REAL-TIME DATE AND TIME
+;
+	public	BIN_DATE_TIME
+	public	MONTH_TABLE
+	public	DAYCNT2
+	public	FEB29
+BIN_DATE_TIME:
+	DB	0		; CENTURY (19 OR 20) OR HOURS (0-23)
+	DB	0		; YEAR IN CENTURY (0-99) OR MINUTES (0-59)
+	DB	0		; MONTH IN YEAR (1-12) OR SECONDS (0-59)
+	DB	0		; DAY IN MONTH (1-31)
+MONTH_TABLE:
+	DW	0		;MJB002 JANUARY
+	DW	31		;MJB002 FEBRUARY
+	DW	59		;MJB002
+	DW	90		;MJB002
+	DW	120		;MJB002
+	DW	151		;MJB002
+	DW	181		;MJB002
+	DW	212		;MJB002
+	DW	243		;MJB002
+	DW	273		;MJB002
+	DW	304		;MJB002
+	DW	334		;MJB002
+DAYCNT2 DW	0000		;MJB002 TEMP FOR CNT OF DAYS SINCE 1-1-80
+FEB29	DB	0		;MJB002 FEBRUARY 29 IN A LEAP YEAR FLAG
+	PATHEND 001,CLK
+
+;;End of modification modification ----------------------------
+
+Public EndFloppy
+EndFloppy Label Byte
+;
+; End of code for virtual floppy drives
+;
+Public EndSwap
+EndSwap Label Byte
+
+	PATHSTART 004,BIO
+
+Public HNUM
+HNUM	DB	0			; number of hardfile (hard drives)
+
+Public HardDrv
+HARDDRV DB	80H			;Physical drive number of first hardfile
+
+
+;
+;  "HDRIVE" is a hard disk with 512 byte sectors
+;
+
+	EVENB
+Public BDSH
+BDSH	DW	-1			; Link to next structure
+	DW	Code
+	DB	80h			; physical drive number
+	DB	"C"                     ; Logical Drive Letter
+Public HDRIVE
+HDRIVE:
+	DW	512
+	DB	1			; Sectors/allocation unit
+	DW	1			; Reserved sectors for DOS
+	DB	2			; No. of allocation tables
+	DW	16			; Number of directory entries
+	DW	0000			; Number of sectors (at 512 bytes each)
+	DB	11111000B		; Media descriptor
+	DW	1			; Number of FAT sectors
+	DW	00			; Sector limit
+	DW	00			; Head limit
+	DW	00			; Hidden sector count
+	DB	0			; TRUE => bigfat
+OPCNTH	DW	0			; Open Ref. Count
+VOLIDH	DB	"NO NAME    ",0         ; Volume ID for this disk
+	DB	3			; Form Factor
+FLAGSH	DW	0020H			; Various Flags
+	dw	40			; number of cylinders
+RecBPBH db	31 dup (?)		; Recommended BPB for drive
+TRACKH	DB	-1			; Last track accessed on this drive
+TIM_LOH DW	-1			; Keep these two contiguous (?)
+TIM_HIH DW	-1
+;
+; End of single hard disk section
+;
+
+
+Public EndOneHard
+EndOneHard Label Byte
+
+
+
+
+;
+;"DRIVEX" is an extra type of drive usually reserved for an
+; additional hard file
+;
+
+	EVENB
+Public BDSX
+BDSX	DW	-1			; Link to next structure
+	DW	Code
+	DB	81h			; physical drive number
+	DB	"D"                     ; Logical Drive Letter
+Public DRIVEX
+DRIVEX:
+	DW	512
+	DB	00			; Sectors/allocation unit
+	DW	1			; Reserved sectors for DOS
+	DB	2			; No. of allocation tables
+	DW	0000			; Number of directory entries
+	DW	0000			; Number of sectors (at 512 bytes each)
+	DB	11111000B		; Media descriptor
+	DW	0000			; Number of FAT sectors
+	DW	00			; Sector limit
+	DW	00			; Head limit
+	DW	00			; Hidden sector count
+	DB	0			; TRUE => bigfat
+OPCNTD	DW	0			; Open Ref. Count
+VOLIDD	DB	"NO NAME    ",0         ; Volume ID for this disk
+	DB	3			; Form Factor
+FLAGSD	DW	0020H			; Various Flags
+	dw	40			; number of cylinders
+RecBPBD db	31 dup (?)		; Recommended BPB for drive
+TRACKD	DB	-1			; Last track accessed on this drive
+TIM_LOD DW	-1			; Keep these two contiguous
+TIM_HID DW	-1
+
+;
+; End of section for two hard disks
+Public EndTwoHard
+EndTwoHard Label Byte
+
+	PATHEND 004,BIO
+
+
+Public TwoHard
+TWOHARD LABEL BYTE
+
+PAGE
+include ms96tpi.inc
+
+;;Rev 3.30 modification ----------------------------
+;Memory allocation for BDSM table.
+	PUBLIC BDSMs
+BDSMs	BDSM_type Max_mini_dsk_num dup (<>)	;currently max. 23
+
+;** End_of_BDSM defined in MSINIT.ASM will be used to set the appropriate
+;** ending address of BDSM table.
+;;End of modification ----------------------------
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;bug005sp
+;
+;;3.3 BUG FIX -SUNILP ------------------------------
+;Paragraph buffer between the BDSMs and MSHARD
+;
+;The relocation code for MSHARD needs this. this cannot be used for 
+;anything. nothing can come before this or after this.....IMPORTANT!!!!
+;don't get too smart and using this buffer for anything!!!!!!
+;
+	db	16 dup(0)
+;
+;end of bug fix buffer
+;;
+;;3.3 BUG FIX -SUNILP------------------------------
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;bug005sp
+CODE	ENDS
+	END

SRC/BUGFIX/CMD/FORMAT/MESSAGES.ASM

@@ -0,0 +1,68 @@
+;	SCCSID = @(#)messages.asm 1.10 85/08/13
+TITLE FORMAT Messages
+
+data	segment public 'DATA'
+
+	public	Yes_Byte
+	public	No_Byte
+	public	msgCRLF
+	public	msgCurrentTrack
+	public	msgSystemTransfered
+	public	msgFormatComplete
+	public	msgInterrupt
+	public	msgInsertDisk
+	public	msgHardDiskWarning
+	public	msgFormatAnother?
+	public	msgInsertDosDisk
+	public	msgReInsertDisk
+	public	msgLabelPrompt
+	public	msgTotalDiskSpace
+	public	msgSystemSpace
+	public	msgBadSpace
+	public	msgDataSpace
+	public	msgFormatNotSupported
+	public	msgInvalidDeviceParameters
+	public	msgErrorInIOCTL
+	public	msgNotBlockDevice
+	public	msgFATwriteError
+	public	msgDirectoryWriteError
+	public	msgAssignedDrive
+	public	msgNeedDrive
+	public	msgBadDosVersion
+	public	msgNoSystemFiles
+	public	msgTooManyFilesOpen
+	public	msgNetDrive
+	public	msgBadCharacters
+	public	msgBadDrive
+	public	msgInvalidParameter
+	public	msgParametersNotSupported
+	public	msgFormatFailure
+	public	msgNotSystemDisk
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;bug007sp
+; 	reintroduce following public for fix
+	public	msgNoRoomDestDisk
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;bug007sp
+	public	msgDiskUnusable
+	public	msgOutOfMemory
+	public	msgWriteProtected
+	public	msgNotReady
+	public	msgBootWriteError
+	public	msgDirectoryReadError
+	public	msgBadVolumeId
+	public	msgWhatIsVolumeId?
+	public	msgIncompatibleParameters
+	public	msgIncompatibleParametersForHardDisk
+	public	msgBadPartitionTable
+	public	msgParametersNotSupportedByDrive
+	public	msgPartitionTableReadError
+	public	msgPartitionTableWriteError
+
+CR	equ	13
+LF	equ	10
+
+; Oem dependent messages
+
+	include messages.inc
+
+data	ends
+	END

SRC/BUGFIX/CMD/FORMAT/MESSAGES.INC

@@ -0,0 +1,139 @@
+;	SCCSID = @(#)messages.inc 1.6 85/08/02
+
+DEBUG	EQU	0		; for Boot sector installation check
+
+IF DEBUG
+	public	msgFormatBroken
+ENDIF
+
+; THE FOLLOWING ONE BYTE CHARACTERS ARE THE PROMPT ANSWERS.
+; THEY MUST BE LOWER CASE, AND THE UPPER TO LOWER, OR LOWER
+; TO LOWER CONVERSION MUST BE DOABLE BY "OR  AL,20h".
+; Yes/No Answers
+
+Yes_Byte	db	"y"
+No_Byte 	db	"n"
+
+msgCRLF db CR, LF, 0
+
+; Status messages
+
+msgCurrentTrack db	"Head: %3d Cylinder: %4d", CR, 0
+
+msgSystemTransfered db "System transferred",CR,LF,0
+
+msgInterrupt db 13,10, 10, 0
+
+; Note: This message must be long enough to wipe out message msgCurrentTrack
+msgFormatComplete db "Format complete              ",CR,LF,0
+
+; Prompts
+
+msgInsertDisk db "Insert new diskette for drive %c:",CR,LF
+	      db "and strike ENTER when ready",0
+
+msgHardDiskWarning db CR,LF
+		   db "WARNING, ALL DATA ON NON-REMOVABLE DISK",CR,LF
+		   db "DRIVE %c: WILL BE LOST!",CR,LF
+		   db "Proceed with Format (Y/N)?",0
+
+msgFormatAnother? db "Format another (Y/N)?",0
+
+msgInsertDosDisk db "Insert DOS disk in drive %c:", CR, LF
+		 db "and strike ENTER when ready", CR, LF, 0
+
+msgReInsertDisk db "Re-insert diskette for drive %c:",0
+
+msgLabelPrompt db "Volume label (11 characters, ENTER for none)? ",0
+
+; Disk usage messages
+
+msgTotalDiskSpace db "%l10d bytes total disk space", CR, LF, 0
+
+msgSystemSpace db "%l10d bytes used by system", CR, LF, 0
+
+msgBadSpace db "%l10d bytes in bad sectors", CR, LF, 0
+
+msgDataSpace db "%l10d bytes available on disk",CR,LF,0
+
+; Error messages
+
+msgFormatNotSupported db "Format not supported on drive %c:", CR,LF,0
+
+msgInvalidDeviceParameters db "Invalid device parameters from device driver"
+			   db CR, LF, 0
+
+msgErrorInIOCTL db "Error in IOCTL call", CR, LF, 0
+
+msgNotBlockDevice db "Not a block device", CR, LF, 0
+
+msgFATwriteError db "Error writing FAT", CR, LF, 0
+
+msgDirectoryWriteError db "Error writing directory", CR, LF, 0
+
+msgAssignedDrive db "Cannot format an ASSIGNed or SUBSTed drive. ", CR, LF, 0
+
+msgNeedDrive db "Drive letter must be specified",CR,LF,0
+
+msgBadDosVersion db "Incorrect DOS version",CR,LF,"$"
+
+msgNoSystemFiles db "Cannot find System Files",CR,LF,0
+
+msgTooManyFilesOpen db "Too many open files",CR,LF,0
+
+msgNetDrive db "Cannot FORMAT a Network drive", CR, LF, 0
+
+msgBadCharacters db "Invalid characters in volume label", CR, LF, 0
+
+msgBadDrive db "Invalid drive specification", CR, LF, 0
+
+msgInvalidParameter db "Invalid parameter", CR, LF, 0
+
+msgParametersNotSupported db	"Parameters not supported",CR,LF,0
+
+; Note: This message must be long enough to wipe out message msgCurrentTrack
+msgFormatFailure db "Format failure               ",CR,LF,0
+
+msgNotSystemDisk db "Disk unsuitable for system disk", CR, LF, 0
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;bug007sp
+;	reintroduce following message for fix
+msgNoRoomDestDisk db "No room for system on destination disk", CR, LF, 0
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;bug007sp
+
+msgDiskUnusable db "Invalid media or Track 0 bad - disk unusable", CR, LF, 0
+
+msgOutOfMemory db "Insufficient memory for system transfer", CR, LF, 0
+
+; Note: This message must be long enough to wipe out message msgCurrentTrack
+msgWriteProtected db "Attempted write-protect violation", CR, LF, 0
+
+; Note: This message must be long enough to wipe out message msgCurrentTrack
+msgNotReady db "Drive not ready                ", CR, LF, 0
+
+
+msgBootWriteError db "Unable to write BOOT", CR, LF, 0
+
+msgDirectoryReadError db "Error reading directory", CR, LF, 0
+
+msgBadVolumeId db "Invalid Volume ID", CR, LF, 0
+
+msgWhatIsVolumeId? db "Enter current Volume Label for drive %c: ", 0
+
+msgIncompatibleParameters db "Parameters not compatible", CR,LF,0
+
+msgIncompatibleParametersForHardDisk db "Parameters not compatible"
+ db " with fixed disk", CR,LF,0
+
+msgBadPartitionTable db "Bad Partition Table", CR, LF, 0
+
+msgParametersNotSupportedByDrive    db "Parameters not Supported by Drive", CR, LF, 0
+
+msgPartitionTableReadError db "Error reading partition table", CR, LF, 0
+
+msgPartitionTableWriteError db "Error writing partition table", CR, LF, 0
+
+IF DEBUG
+msgFormatBroken db "Format Broken", CR, LF, 0
+ENDIF
+

SRC/CMD/FORMAT/BOOTMES.INC

@@ -0,0 +1,9 @@
+;	SCCSID = @(#)bootmes.inc	1.1 85/04/18
+
+; Message Include file for OEMFOR.ASM
+
+; THIS IS A SPECIAL MESSAGE WHICH IS INCLUDED IN THE "FAKE" IO.SYS
+;  FILE PLACED ON DISKS FORMATTED /B. NOTE THAT IT IS NUL TERMINATED.
+
+NO_SYS_MESS:
+	DB	"Non-System disk or disk error",13,10,0

SRC/CMD/FORMAT/FILESIZE.INC

@@ -0,0 +1,6 @@
+
+	%out ..filesize.inc
+
+BIOS_SIZE	equ	 22528		; actually  22341
+DOS_SIZE	equ	 30208		; actually  30128
+

SRC/CMD/FORMAT/FORMAT.LNK

@@ -0,0 +1,2 @@
+format.obj forproc.obj messages.obj oemfor.obj ..\..\libc\printf.obj
+format.exe /m;

SRC/CMD/FORMAT/FORPROC.ASM

@@ -0,0 +1,141 @@
+;	SCCSID = @(#)forproc.asm	1.2 85/07/25
+.xlist
+.xcref
+BREAK   MACRO   subtitle
+	SUBTTL  subtitle
+	PAGE
+ENDM
+
+	INCLUDE SYSCALL.INC
+.cref
+.list
+data	segment	public 'DATA'
+data	ends
+
+code    segment public 'CODE'
+	assume  cs:code,ds:data
+
+	PUBLIC  FormatAnother?,Yes?,REPORT,USER_STRING
+	public	fdsksiz,badsiz,syssiz,datasiz,biosiz
+
+	extrn   std_printf:near,crlf:near,PrintString:near
+
+data segment
+	extrn	driveLetter:byte
+
+; In formes.asm
+	extrn	msgInsertDisk:byte
+	extrn	msgFormatAnother?:byte
+	extrn	msgTotalDiskSpace:byte
+	extrn	msgSystemSpace:byte
+	extrn	msgBadSpace:byte
+	extrn	msgDataSpace:byte
+	extrn	yes_byte:byte
+	extrn	no_byte:byte
+
+	extrn   inbuff:byte
+
+ptr_msgTotalDiskSpace	dw	offset msgTotalDiskSpace
+fdsksiz			dd      0
+
+ptr_msgSystemSpace	dw	offset msgSystemSpace
+syssiz  		dd      0
+biosiz  		dd      0
+
+ptr_msgBadSpace		dw	offset msgBadSpace
+badsiz  		dd      0
+
+ptr_msgDataSpace	dw	offset msgDataSpace
+datasiz			dd      0
+
+ptr_msgInsertDisk	dw	offset msgInsertDisk
+			dw	offset driveLetter
+data ends
+
+FormatAnother? proc near
+; Wait for key. If yes return carry clear, else no. Insures
+;   explicit Y or N answer.
+	lea	dx, msgFormatAnother?
+	call	PrintString
+	CALL    Yes?
+	JNC     WAIT20
+	JZ      WAIT20
+	CALL    CRLF
+	JMP     SHORT FormatAnother?
+FormatAnother? endp
+
+Yes? proc near
+
+; Wait for key. If YES return carry clear,else carry set.
+;   If carry is set, Z is set if explicit NO, else key was not Yes or No.
+	CALL    USER_STRING
+	JNZ     GETBYT
+	XOR     AL,AL                   ; So that CMP with [NO_BYTE] is NZ
+	JMP     SHORT CHECK_NO
+
+GETBYT:
+	MOV     AL,BYTE PTR [INBUFF+2]
+	OR      AL,20H                  ; Convert to lower case
+	CMP     AL,[YES_BYTE]
+	JZ      WAIT20                  ; Carry clear if jump
+CHECK_NO:
+	CMP     AL,[NO_BYTE]
+	STC                             ; Set carry (wasn't Yes)
+WAIT20: RET
+
+Yes? endp
+
+USER_STRING:
+; Get a string from user. Z is set if user typed no chars (imm CR)
+;  We need to flush a second time to get rid of incoming Kanji characters also.
+	MOV     AX,(STD_CON_INPUT_FLUSH SHL 8) + 0      ; Clean out input
+	INT     21H
+	MOV     DX,OFFSET INBUFF
+	MOV     AH,STD_CON_STRING_INPUT
+	INT     21H
+	MOV     AX,(STD_CON_INPUT_FLUSH SHL 8) + 0      ; Clean out input
+	INT     21H
+	CMP     BYTE PTR [INBUFF+1],0
+	RET
+
+;*********************************************
+; Make a status report including the following information:
+; Total disk capacity
+; Total system area used
+; Total bad space allocated
+; Total data space available
+
+REPORT:
+	lea	dx, ptr_msgTotalDiskSpace
+	call	std_printf
+	cmp     WORD PTR SYSSIZ,0
+	JNZ     SHOWSYS
+	cmp     WORD PTR SYSSIZ+2,0
+	JZ      CHKBAD
+SHOWSYS:
+	MOV     dx,OFFSET ptr_msgSystemSpace
+	CALL    std_printf              ;Report space used by system
+CHKBAD:
+	cmp     WORD PTR BADSIZ,0
+	JNZ     SHOWBAD
+	cmp     WORD PTR BADSIZ+2,0
+	JZ      SHOWDATA
+SHOWBAD:
+	lea	dx, ptr_msgBadSpace
+	call	std_printf
+SHOWDATA:
+	MOV     CX,WORD PTR FDSKSIZ
+	MOV     BX,WORD PTR FDSKSIZ+2
+	SUB     CX,WORD PTR BADSIZ
+	SBB     BX,WORD PTR BADSIZ+2
+	SUB     CX,WORD PTR SYSSIZ
+	SBB     BX,WORD PTR SYSSIZ+2
+	MOV     word ptr datasiz,CX
+	MOV     word ptr datasiz+2,BX
+	lea	dx, ptr_msgDataSpace
+	call	std_printf
+	call	crlf
+	RET
+
+code    ends
+	end

SRC/CMD/FORMAT/MAKEFILE

@@ -0,0 +1,58 @@
+#**     makefile for format
+
+DEST	=format
+MSG	=messages
+
+#	Path definitions
+
+BIOS	=..\..\BIOS
+BOOT	=..\..\BOOT
+DOS	=..\..\DOS
+
+#       Definitions for assembler
+
+ASM	=masm
+AFLAGS	=-Mx -t
+AINC	=-I..\..\inc -I$(DOS)
+
+#       Definitions for C compiler
+
+CC	=cl
+CFLAGS	=-c -Ox -Zlp
+CINC	=-I..\..\h
+
+#	Definitions for linker
+
+LINK	=link
+LIBC	=..\..\libc
+
+
+# Rules and Dependencies follow
+
+filesize.inc:	$(DOS)\msdos.sys $(BIOS)\io.sys
+	GWBASIC MAKE_INC
+
+FORMAT.OBJ: FORMAT.ASM $(DOS)\DOSMAC.INC $(DOS)\BPB.INC \
+     $(DOS)\DIRENT.INC $(DOS)\DPB.INC $(DOS)\CURDIR.INC \
+     $(DOS)\CPMFCB.INC $(DOS)\PDB.INC \
+     $(DOS)\ERROR.INC $(DOS)\SYSCALL.INC $(DOS)\IOCTL.INC
+	masm $(AFLAGS) $(AINC) FORMAT;
+
+$(MSG).OBJ: $(MSG).ASM $(MSG).inc
+	masm $(AFLAGS) $(AINC) $(MSG);
+
+FORPROC.OBJ: FORPROC.ASM $(DOS)\SYSCALL.INC
+	masm $(AFLAGS) $(AINC) FORPROC;
+
+OEMFOR.OBJ: OEMFOR.ASM $(DOS)\DOSMAC.INC $(DOS)\SYSCALL.INC $(DOS)\BPB.INC \
+     $(DOS)\DIRENT.INC bootmes.inc $(DOS)\IOCTL.INC \
+     $(BOOT)\BOOT.INC $(BOOT)\BOOT11.INC filesize.inc
+	masm $(AFLAGS) $(AINC) OEMFOR;
+	
+$(LIBC)\printf.obj: $(LIBC)\printf.asm
+	masm $(AFLAGS) $(AINC) $(LIBC)\printf,$(LIBC)\printf;
+
+FORMAT.EXE:	FORMAT.OBJ FORPROC.OBJ $(MSG).OBJ OEMFOR.OBJ $(LIBC)\PRINTF.OBJ
+	LINK  @FORMAT.LNK
+	convert format.exe
+	del format.exe

SRC/CMD/FORMAT/MESSAGES.ASM

@@ -0,0 +1,68 @@
+;	SCCSID = @(#)messages.asm 1.10 85/08/13
+TITLE FORMAT Messages
+
+data	segment public 'DATA'
+
+	public	Yes_Byte
+	public	No_Byte
+	public	msgCRLF
+	public	msgCurrentTrack
+	public	msgSystemTransfered
+	public	msgFormatComplete
+	public	msgInterrupt
+	public	msgInsertDisk
+	public	msgHardDiskWarning
+	public	msgFormatAnother?
+	public	msgInsertDosDisk
+	public	msgReInsertDisk
+	public	msgLabelPrompt
+	public	msgTotalDiskSpace
+	public	msgSystemSpace
+	public	msgBadSpace
+	public	msgDataSpace
+	public	msgFormatNotSupported
+	public	msgInvalidDeviceParameters
+	public	msgErrorInIOCTL
+	public	msgNotBlockDevice
+	public	msgFATwriteError
+	public	msgDirectoryWriteError
+	public	msgAssignedDrive
+	public	msgNeedDrive
+	public	msgBadDosVersion
+	public	msgNoSystemFiles
+	public	msgTooManyFilesOpen
+	public	msgNetDrive
+	public	msgBadCharacters
+	public	msgBadDrive
+	public	msgInvalidParameter
+	public	msgParametersNotSupported
+	public	msgFormatFailure
+	public	msgNotSystemDisk
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;bug007sp
+; 	reintroduce following public for fix
+;	public	msgNoRoomDestDisk
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;bug007sp
+	public	msgDiskUnusable
+	public	msgOutOfMemory
+	public	msgWriteProtected
+	public	msgNotReady
+	public	msgBootWriteError
+	public	msgDirectoryReadError
+	public	msgBadVolumeId
+	public	msgWhatIsVolumeId?
+	public	msgIncompatibleParameters
+	public	msgIncompatibleParametersForHardDisk
+	public	msgBadPartitionTable
+	public	msgParametersNotSupportedByDrive
+	public	msgPartitionTableReadError
+	public	msgPartitionTableWriteError
+
+CR	equ	13
+LF	equ	10
+
+; Oem dependent messages
+
+	include messages.inc
+
+data	ends
+	END

SRC/CMD/FORMAT/MESSAGES.INC

@@ -0,0 +1,139 @@
+;	SCCSID = @(#)messages.inc 1.6 85/08/02
+
+DEBUG	EQU	0		; for Boot sector installation check
+
+IF DEBUG
+	public	msgFormatBroken
+ENDIF
+
+; THE FOLLOWING ONE BYTE CHARACTERS ARE THE PROMPT ANSWERS.
+; THEY MUST BE LOWER CASE, AND THE UPPER TO LOWER, OR LOWER
+; TO LOWER CONVERSION MUST BE DOABLE BY "OR  AL,20h".
+; Yes/No Answers
+
+Yes_Byte	db	"y"
+No_Byte 	db	"n"
+
+msgCRLF db CR, LF, 0
+
+; Status messages
+
+msgCurrentTrack db	"Head: %3d Cylinder: %4d", CR, 0
+
+msgSystemTransfered db "System transferred",CR,LF,0
+
+msgInterrupt db 13,10, 10, 0
+
+; Note: This message must be long enough to wipe out message msgCurrentTrack
+msgFormatComplete db "Format complete              ",CR,LF,0
+
+; Prompts
+
+msgInsertDisk db "Insert new diskette for drive %c:",CR,LF
+	      db "and strike ENTER when ready",0
+
+msgHardDiskWarning db CR,LF
+		   db "WARNING, ALL DATA ON NON-REMOVABLE DISK",CR,LF
+		   db "DRIVE %c: WILL BE LOST!",CR,LF
+		   db "Proceed with Format (Y/N)?",0
+
+msgFormatAnother? db "Format another (Y/N)?",0
+
+msgInsertDosDisk db "Insert DOS disk in drive %c:", CR, LF
+		 db "and strike ENTER when ready", CR, LF, 0
+
+msgReInsertDisk db "Re-insert diskette for drive %c:",0
+
+msgLabelPrompt db "Volume label (11 characters, ENTER for none)? ",0
+
+; Disk usage messages
+
+msgTotalDiskSpace db "%l10d bytes total disk space", CR, LF, 0
+
+msgSystemSpace db "%l10d bytes used by system", CR, LF, 0
+
+msgBadSpace db "%l10d bytes in bad sectors", CR, LF, 0
+
+msgDataSpace db "%l10d bytes available on disk",CR,LF,0
+
+; Error messages
+
+msgFormatNotSupported db "Format not supported on drive %c:", CR,LF,0
+
+msgInvalidDeviceParameters db "Invalid device parameters from device driver"
+			   db CR, LF, 0
+
+msgErrorInIOCTL db "Error in IOCTL call", CR, LF, 0
+
+msgNotBlockDevice db "Not a block device", CR, LF, 0
+
+msgFATwriteError db "Error writing FAT", CR, LF, 0
+
+msgDirectoryWriteError db "Error writing directory", CR, LF, 0
+
+msgAssignedDrive db "Cannot format an ASSIGNed or SUBSTed drive. ", CR, LF, 0
+
+msgNeedDrive db "Drive letter must be specified",CR,LF,0
+
+msgBadDosVersion db "Incorrect DOS version",CR,LF,"$"
+
+msgNoSystemFiles db "Cannot find System Files",CR,LF,0
+
+msgTooManyFilesOpen db "Too many open files",CR,LF,0
+
+msgNetDrive db "Cannot FORMAT a Network drive", CR, LF, 0
+
+msgBadCharacters db "Invalid characters in volume label", CR, LF, 0
+
+msgBadDrive db "Invalid drive specification", CR, LF, 0
+
+msgInvalidParameter db "Invalid parameter", CR, LF, 0
+
+msgParametersNotSupported db	"Parameters not supported",CR,LF,0
+
+; Note: This message must be long enough to wipe out message msgCurrentTrack
+msgFormatFailure db "Format failure               ",CR,LF,0
+
+msgNotSystemDisk db "Disk unsuitable for system disk", CR, LF, 0
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;bug007sp
+;	reintroduce following message for fix
+;msgNoRoomDestDisk db "No room for system on destination disk", CR, LF, 0
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;bug007sp
+
+msgDiskUnusable db "Invalid media or Track 0 bad - disk unusable", CR, LF, 0
+
+msgOutOfMemory db "Insufficient memory for system transfer", CR, LF, 0
+
+; Note: This message must be long enough to wipe out message msgCurrentTrack
+msgWriteProtected db "Attempted write-protect violation", CR, LF, 0
+
+; Note: This message must be long enough to wipe out message msgCurrentTrack
+msgNotReady db "Drive not ready                ", CR, LF, 0
+
+
+msgBootWriteError db "Unable to write BOOT", CR, LF, 0
+
+msgDirectoryReadError db "Error reading directory", CR, LF, 0
+
+msgBadVolumeId db "Invalid Volume ID", CR, LF, 0
+
+msgWhatIsVolumeId? db "Enter current Volume Label for drive %c: ", 0
+
+msgIncompatibleParameters db "Parameters not compatible", CR,LF,0
+
+msgIncompatibleParametersForHardDisk db "Parameters not compatible"
+ db " with fixed disk", CR,LF,0
+
+msgBadPartitionTable db "Bad Partition Table", CR, LF, 0
+
+msgParametersNotSupportedByDrive    db "Parameters not Supported by Drive", CR, LF, 0
+
+msgPartitionTableReadError db "Error reading partition table", CR, LF, 0
+
+msgPartitionTableWriteError db "Error writing partition table", CR, LF, 0
+
+IF DEBUG
+msgFormatBroken db "Format Broken", CR, LF, 0
+ENDIF
+

SRC/CMD/MAKEFILE

@@ -0,0 +1,14 @@
+make=msmake /I makefile
+
+all:
+	cd format
+	$(make)
+	cd ..\print
+	$(make)
+	cd ..\sort
+	$(make)
+	cd ..\sys
+	$(make)
+	cd ..
+
+

SRC/CMD/PRINT/MAKEFILE

@@ -0,0 +1,61 @@
+#**     makefile for print
+
+DEST	=print
+MSG	=messages
+
+#	Path definitions
+
+BIOS	=..\..\BIOS
+DOS	=..\..\DOS
+
+#       Definitions for assembler
+
+ASM	=masm
+AFLAGS	=-Mx -t
+AINC	=-I..\..\inc -I$(DOS)
+
+#       Definitions for C compiler
+
+CC	=cl
+CFLAGS	=-c -Ox -Zlp
+CINC	=-I..\..\h
+
+#	Definitions for linker
+
+LINK	=link
+LIBC	=..\..\libc
+
+
+# Rules and Dependencies follow
+
+PRINT_RM.OBJ: PRINT_RM.ASM print_rm.inc PRIDEFS.inc \
+    $(DOS)\DEVSYM.INC $(DOS)\SYSCALL.INC $(DOS)\ERROR.INC \
+    $(DOS)\SYSVAR.INC $(DOS)\FIND.INC
+	masm $(AFLAGS) $(AINC) PRINT_RM;
+
+PRINT_R.OBJ: PRINT_R.ASM PRIDEFS.inc \
+    $(DOS)\DEVSYM.INC $(DOS)\SYSCALL.INC $(DOS)\ERROR.INC \
+    $(DOS)\SYSVAR.INC $(DOS)\FIND.INC
+	masm $(AFLAGS) $(AINC) PRINT_R;
+
+PRINT_T.OBJ: PRINT_T.ASM PRIDEFS.inc \
+    $(DOS)\DEVSYM.INC $(DOS)\SYSCALL.INC $(DOS)\ERROR.INC \
+    $(DOS)\SYSVAR.INC $(DOS)\FIND.INC
+	masm $(AFLAGS) $(AINC) PRINT_T;
+
+PRINT_TM.OBJ: PRINT_TM.ASM print_tm.inc PRIDEFS.inc \
+    $(DOS)\DEVSYM.INC $(DOS)\SYSCALL.INC $(DOS)\ERROR.INC \
+    $(DOS)\SYSVAR.INC $(DOS)\FIND.INC
+	masm $(AFLAGS) $(AINC) PRINT_TM;
+
+NPRINTF.OBJ: NPRINTF.ASM PRIDEFS.inc \
+    $(DOS)\DEVSYM.INC $(DOS)\SYSCALL.INC $(DOS)\ERROR.INC \
+    $(DOS)\SYSVAR.INC $(DOS)\FIND.INC
+	masm $(AFLAGS) $(AINC) NPRINTF;
+
+PRINT.EXE: PRINT_RM.OBJ PRINT_R.OBJ PRINT_T.OBJ \
+    PRINT_TM.OBJ NPRINTF.OBJ
+	LINK @PRINT.LNK
+	CONVERT PRINT.EXE
+	DEL PRINT.EXE
+

SRC/CMD/PRINT/NPRINTF.ASM

@@ -0,0 +1,386 @@
+;	SCCSID = @(#)nprintf.asm	4.1 85/07/17
+	INCLUDE pridefs.inc
+
+
+BREAK	<Message Printing Routine>
+
+;
+;	MSDOS V3.00 PRINT
+;
+;	Message Printing Routine
+;
+
+
+DATA	    SEGMENT PUBLIC BYTE
+
+	    extrn   crlf_ptr:word
+
+Public NPR001S, NPR001E
+NPR001S 	equ	$
+
+PRINTF_LEFT	DB  0
+PRINTF_LONG	DB  0
+PRINTF_HEX	DB  0
+TABLE_INDEX	DB  0
+S_FLAG		DB  0
+PRINTF_WIDTH	DW  0
+PRINTF_BASE	DW  0
+PAD_CHAR	DB  " "
+
+PRINTF_TABLE DB "0123456789ABCDEFabcdef"
+
+PRINTF_STACK   STRUC
+OLDES	DW  ?
+OLDDS	DW  ?
+OLDSI	DW  ?
+OLDDI	DW  ?
+OLDAX	DW  ?
+OLDBX	DW  ?
+OLDCX	DW  ?
+OLDBP	DW  ?
+STRING	DW  ?
+OLDCS	DW  ?
+PRINTF_STACK   ENDS
+
+PRINTF_ARGS    STRUC
+CONSTR	DW ?
+ARG	DW ?
+PRINTF_ARGS    ENDS
+
+BUFSIZ	EQU    20
+PRINTF_BUF DB  BUFSIZ DUP (?)
+	db	0			;This buffer is always nul terminated
+BUFEND DW   $-PRINTF_BUF
+
+NPR001E 	equ	$
+
+DATA	    ENDS
+
+
+Code	Segment public para
+
+ASSUME	CS:DG,DS:nothing,ES:nothing,SS:Stack
+
+	PUBLIC	PRINTF,STD_PRINTF,PRINTF_CRLF
+
+PRINTF_CRLF:
+	CALL	STD_PRINTF
+crlf2:
+	mov	dx,offset dg:crlf_ptr
+STD_PRINTF:
+	PUSH	DX
+PRINTF:
+	PUSH	BP			;Save the callers' registers
+	PUSH	CX
+	PUSH	BX
+	PUSH	AX
+	PUSH	DI
+	PUSH	SI
+	PUSH	ES
+	PUSH	DS
+	MOV	BP,SP
+	PUSH	CS
+	POP	ES			;ES points to Printf segment
+	CALL	Clear_flags		; initialize the world
+
+	MOV	DI,DS
+	MOV	SI,ES
+	CMP	SI,DI
+	JZ	S
+	HLT
+S:
+
+	MOV	DI,OFFSET DG:PRINTF_BUF ;DI points to the output buffer
+	MOV	BP,[BP.STRING]		;BP points to the argument list
+	MOV	SI,DS:[BP]		;SI points to the control string
+	XOR	BX,BX			;BX is the index into the arg list
+GET_CHAR:
+	LODSB				;Get a character
+	CMP	AL,"%"                  ;Is it a conversion specifier?
+	JZ	CONV_CHAR		;Yes - find out which one
+	OR	AL,AL			;Is it the end of the control string?
+	JZ	PRINTF_DONE		;Yes - then we're done
+	CALL	OUTCHR			;Otherwise store the character
+	JMP	SHORT GET_CHAR		;And go get another
+
+PRINTF_DONE:
+	CALL	FLUSH
+	POP	DS
+	POP	ES
+	POP	SI
+	POP	DI
+	POP	AX
+	POP	BX
+	POP	CX
+	POP	BP
+	POP	DX
+	RET
+
+PRINTF_PERCENT:
+	CALL	OUTCHR
+	JMP	GET_CHAR
+
+CONV_CHAR:
+	;Look for any format specifiers preceeding the conversion character
+	LODSB
+	CMP	AL,"%"                      ;Just print the %
+	JZ	PRINTF_PERCENT
+	CMP	AL,"-"                      ;Right justify the field
+	JZ	LEFT_ADJ
+	CMP	AL,"+"                      ;Left justify the field
+	JZ	NXT_CONV_CHAR
+	CMP	AL,"L"                      ;Is it a long integer
+	JZ	LONG_INT
+	CMP	AL,"l"
+	JZ	LONG_INT
+	CMP	AL,"0"                      ;Is it a precision specification
+	JB	LOOK_CONV_CHAR
+	CMP	AL,"9"
+	JA	LOOK_CONV_CHAR
+	CMP	AL,"0"
+	JNZ	NOT_PAD
+	CMP	CS:[PRINTF_WIDTH],0
+	JNZ	NOT_PAD
+	MOV	CS:BYTE PTR [PAD_CHAR],"0"
+NOT_PAD:
+	PUSH	AX			    ;Adjust decimal place on precision
+	MOV	AX,10
+	MUL	CS:[PRINTF_WIDTH]
+	MOV	CS:[PRINTF_WIDTH],AX
+	POP	AX
+	XOR	AH,AH
+	SUB	AL,"0"
+	ADD	CS:[PRINTF_WIDTH],AX	       ;And save the total
+	JMP	SHORT NXT_CONV_CHAR
+
+	;Set the correct flags for the options in a conversion
+
+LEFT_ADJ:
+	INC	CS:BYTE PTR[PRINTF_LEFT]
+	JMP	SHORT NXT_CONV_CHAR
+
+LONG_INT:
+	INC	CS:BYTE PTR[PRINTF_LONG]
+NXT_CONV_CHAR:
+	JMP	CONV_CHAR
+
+	;Look for a conversion character
+
+LOOK_CONV_CHAR:
+	CMP	AL,"X"
+	JZ	HEX_UP
+
+	;Make all other conversion characters upper case
+
+	CMP	AL,"a"
+	JB	CAPS
+	CMP	AL,"z"
+	JG	CAPS
+	AND	AL,0DFH
+CAPS:
+	CMP	AL,"X"
+	JZ	HEX_LO
+	CMP	AL,"D"
+	JZ	DECIMAL
+	CMP	AL,"C"
+	JZ	C_PUT_CHAR
+	CMP	AL,"S"
+	JZ	S_PUT_STRG
+
+	;Didn't find any legal conversion character - IGNORE it
+
+	call	clear_flags
+	jmp	get_char
+
+HEX_LO:
+	MOV	CS:[TABLE_INDEX],6		;Will print lower case hex digits
+HEX_UP:
+	MOV	CS:[PRINTF_BASE],16    ;Hex conversion
+	JMP	CONV_TO_NUM
+
+DECIMAL:
+	MOV	CS:[PRINTF_BASE],10    ;Decimal conversion
+	JMP	CONV_TO_NUM
+
+S_PUT_STRG:
+	INC	CS:[S_FLAG]	       ;It's a string specifier
+C_PUT_CHAR:
+	PUSH	SI		       ;Save pointer to control string
+	MOV	SI,BX
+	ADD	BX,2
+	MOV	SI,ds:[BP+SI.ARG]      ;Point to the % string or character
+	CMP	BYTE PTR CS:[S_FLAG],0
+	JNZ	S_PUT_1
+	LODSB
+	cmp	al,0
+	jz	short c_s_end
+	CALL	OUTCHR		       ;Put it into our buffer
+	JMP	SHORT C_S_END
+
+S_PUT_1:
+	mov	cx,cs:[printf_width]
+	or	cx,cx
+	jz	s_put_2
+	cmp	cs:byte ptr[printf_left],0
+	jnz	s_put_2
+	push	si
+	call	Pad_string
+	pop	si
+s_put_2:
+	push	si
+s_put_3:
+	LODSB			       ;Put them all in our buffer
+	CMP	AL,0
+	jz	s_put_4
+	CALL	OUTCHR
+	jmp	short S_PUT_3
+s_put_4:
+	pop	si
+	cmp	byte ptr[printf_left],0
+	jz	c_s_end
+	mov	cx,cs:[printf_width]
+	or	cx,cx
+	jz	c_s_end
+	call	Pad_string
+C_S_END:
+	call	clear_flags
+	POP	SI		       ;Restore control string pointer
+	JMP	GET_CHAR	       ;Go get another character
+
+pad_string:
+	xor	dx,dx
+count_loop:
+	lodsb
+	or	al,al
+	jz	count_done
+	inc	dx
+	jmp	short count_loop
+count_done:
+	sub	cx,dx
+	jbe	count_ret
+	call	pad
+count_ret:
+	ret
+
+CONV_TO_NUM:
+
+	PUSH	SI		    ;Save pointer to control string
+	MOV	SI,BX		    ;Get index into argument list
+	ADD	BX,2		    ;Increment the index
+	MOV	AX,ds:[BP+SI.ARG]   ;Lo word of number in SI
+	CMP	BYTE PTR CS:[PRINTF_LONG],0	;Is this is a short or long integer?
+	JZ	NOT_LONG_INT
+	MOV	SI,BX			     ;Copy index
+	ADD	BX,2			     ;Increment the index
+	MOV	DX,ds:[BP+SI.ARG]	     ;Hi word of number in BP
+	JMP	SHORT DO_CONV
+NOT_LONG_INT:
+	XOR	DX,DX			     ;Hi word is zero
+DO_CONV:
+	PUSH	BX			     ;Save index into arguemnt list
+	MOV	si,CS:[PRINTF_BASE]
+	MOV	cx,CS:[PRINTF_WIDTH]
+	CALL	PNUM
+	CALL	PAD
+CONV_DONE:
+	call	clear_flags
+	POP	BX
+	POP	SI
+	jmp	get_char
+
+PNUM:
+	DEC	CX
+	PUSH	AX
+	MOV	AX,DX
+	XOR	DX,DX
+	DIV	SI
+	MOV	BX,AX
+	POP	AX
+	DIV	SI
+	XCHG	BX,DX
+	PUSH	AX
+	OR	AX,DX
+	POP	AX
+	JZ	DO_PAD
+	PUSH	BX
+	CALL	PNUM
+	POP	BX
+	JMP	SHORT REM
+DO_PAD:
+	CMP	CS:BYTE PTR[PRINTF_LEFT],0
+	JNZ	REM
+	CALL	PAD
+REM:
+	MOV	AX,BX
+	CMP	AL,10
+	JB	NOT_HEX
+	CMP	CS:BYTE PTR [PRINTF_HEX],0
+	JNZ	NOT_HEX
+	ADD	AL,CS:BYTE PTR [TABLE_INDEX]
+NOT_HEX:
+	MOV	BX,OFFSET dg:PRINTF_TABLE
+	PUSH	DS
+	PUSH	CS
+	POP	DS
+	XLAT	0
+	POP	DS
+	push	cx
+	CALL	OUTCHR
+	pop	cx
+	RET
+
+PAD:
+	OR	CX,CX
+	JLE	PAD_DONE
+	MOV	AL,CS:BYTE PTR [PAD_CHAR]
+PAD_LOOP:
+	push	cx
+	CALL	OUTCHR
+	pop	cx
+	LOOP	PAD_LOOP
+PAD_DONE:
+	RET
+
+OUTCHR:
+	STOSB
+	CMP	DI,offset dg:bufend-1	   ;Don't count the nul
+	jz	foob2
+	ret
+foob2:
+	MOV	CX,BUFSIZ
+WRITE_CHARS:
+	push	bx
+	MOV	BX,1
+	push	ds
+	PUSH	CS
+	POP	DS
+	MOV	DX,OFFSET dg:PRINTF_BUF
+	MOV	AH,WRITE
+	INT	21H
+	pop	ds
+	pop	bx
+	MOV	DI,OFFSET dg:PRINTF_BUF
+	RET
+
+FLUSH:
+	CMP	DI,OFFSET dg:PRINTF_BUF
+	jnz	foob1
+	ret
+foob1:
+	SUB	DI,OFFSET dg:PRINTF_BUF
+	MOV	CX,DI
+	call	write_chars
+	ret
+
+CLEAR_FLAGS:
+	XOR	ax,ax
+	MOV	BYTE PTR CS:[PRINTF_LEFT],al	   ;Reset justifing flag
+	MOV	BYTE PTR CS:[PRINTF_LONG],al	   ;Reset long flag
+	MOV	BYTE PTR CS:[TABLE_INDEX],al	   ;Reset hex table index
+	MOV	CS:[PRINTF_WIDTH],ax		   ;Reinitialize width to 0
+	MOV	BYTE PTR CS:[PAD_CHAR]," "         ;Reset padding character
+	MOV	BYTE PTR CS:[S_FLAG],al 	   ;Clear the string flag
+	ret
+
+Code	Ends
+	End

SRC/CMD/PRINT/PRIDEFS.INC

@@ -0,0 +1,213 @@
+;	SCCSID = @(#)pridefs.asm	4.4 85/07/17
+title	3.00 Print Utility
+
+;MS-DOS PSPRINT/PRINT program for background printing of text files
+;	to the list device.
+;
+;  IBM SERVER VERSION
+;
+;	 INT 28H is a software interrupt generated by the  DOS
+;	 in  its  I/O  wait  loops.   This spooler can be assembled for
+;	 operation using only this interrupt  which  is  portable  from
+;	 system to  system.  It may also be assembled to use a hardware
+;	 timer interrupt in addition to  the  software	INT  28H.   The
+;	 purpose  of  using hardware interrupts is to allow printing to
+;	 continue during programs which do not	enter  the  system  and
+;	 therefore causes the INT 28H to go away.  A timer interrupt is
+;	 chosen in preference to a  "printer  buffer  empty"  interrupt
+;	 because  PRINT  in the timer form is generic.	It can be given
+;	 the name of any currently installed character	device	as  the
+;	 "printer",  this  makes  it  portable  to  devices  which  are
+;	 installed by the user even in the hardware case.  It could  be
+;	 modified to use a buffer empty interrupt (no code is given for
+;	 this case), if this is done the PROMPT and BADMES messages and
+;	 their associated  code should be removed as PRINT will then be
+;	 device specific.
+;
+;	V1.00	07/03/82
+;	V2.00	07/05/83	A.Reynolds
+;		New INT 2FH interface, Pathnames, context switch.
+;	V2.50	09/14/83	M.A.Ulloa
+;		Turned it back to a print
+;		11/21/83	M.A.Ulloa
+;		Repaired bug in file cancel code
+;		11/28/83	M.A.Ulloa
+;		Added int 23 and 24 handlers to transient.
+;		01/27/84	M.A.Ulloa
+;		Allways checks for valid drive.
+;	V3.00	02/03/84	M.A.Ulloa
+;		Partitioned so as to assemble on a PC
+;		By the by, it is V3.00 now.
+;		05/23/85	K.G.Schulmeisters
+;		Chains into INT19 (bootstrap) to unhook
+;		INT_1C (timer) and INT_15 (AT's Wait On Event)
+;
+
+
+;	Aaron's rambling:
+;
+; BEWARE ALL YEE WHO ENTER HERE.
+;    PRINT is an amazingly complex program.  MS-DOS versions below 3.00 are
+;    NOT re-entrant, this means that this utility is basically not a
+;    possibility.  It gets by on the fact that it is written by the same
+;    person who wrote the OS.  Since you are not that person, you must be very
+;    careful about making any modification to this utility.  There are a
+;    number of things which may seem to be unnecessary on first examination.
+;    BEWARE, almost every line of code is there for a very good reason.  The
+;    order of things is very carefully chosen.	PRINT is full of potential
+;    windows, make sure that you do not open one by careless modification.  Do
+;    not look for a lot of help from the comments, a complete explanation
+;    would probably fill a book.  A succesful modifier will have an in-depth
+;    knowledge of the internal function of MS-DOS, and of the PRINT utility
+;    itself through in depth study of the comments AND the code.
+
+
+subttl	General Definition
+page
+
+
+FALSE	EQU	0
+TRUE	EQU	NOT FALSE
+
+;IBM	EQU	TRUE
+;IBMVER	EQU	IBM
+;MSVER	EQU	FALSE
+
+include version.inc
+
+	IF	MSVER
+HARDINT EQU	FALSE			;No hardware ints
+AINT	EQU	FALSE			;No need to do interrupt acknowledge
+	ENDIF
+
+	IF	IBM
+HARDINT EQU	TRUE
+INTLOC	EQU	1CH			;Hardware interrupt location (Timer)
+REBOOT	EQU	19H			;ROM BIOS "Bootstrap"
+AINT	EQU	TRUE			;Acknowledge interrupts
+EOI	EQU	20H			;End Of Interrupt "instruction"
+AKPORT	EQU	20H			;Interrupt Acknowledge port
+	ENDIF
+
+;  The following values have to do with the ERRCNT variable and the CNTMES
+;  message.  The values define levels at wich it is assumed an off-line error
+;  exists.  ERRCNT1 defines the value of ERRCNT above which the CNTMES message
+;  is printed by the transient.  ERRCNT2 defines the value of ERRCNT above
+;  which the resident will give up trying to print messages on the printer, it
+;  is much greater than ERRCNT1 because a much tighter loop is involved.  The
+;  bounding event which determines the correct value is the time required to
+;  do a form feed.
+
+	IF	IBM
+ERRCNT1 EQU	1500
+ERRCNT2 EQU	20000
+	ELSE
+ERRCNT1 EQU	1500
+ERRCNT2 EQU	20000
+	ENDIF
+
+
+;WARNING DANGER WARNING:
+;   PRINT is a systems utility. It is clearly understood that it may have
+;   to be entirely re-written for future versions of MS-DOS. The following
+;   TWO vectors are version specific, they may not exist at all in future
+;   versions. If they do exist, they may function differently.
+; ANY PROGRAM WHICH IMITATES PRINTS USE OF THESE VECTORS IS ALSO A SYSTEMS
+; UTILITY AND IS THEREFORE NOT VERSION PORTABLE IN ANY WAY SHAPE OR FORM.
+; YOU HAVE BEEN WARNED, "I DID IT THE SAME WAY PRINT DID" IS NOT AN REASON
+; TO EXPECT A PROGRAM TO WORK ON FUTURE VERSIONS OF MS-DOS.
+
+SOFTINT EQU	28H			;Software interrupt generated by DOS
+ComInt	EQU	2FH			;Communications interrupt used by PSPRINT
+					;    Multiplex number 0 and 1
+
+;----- Default (and Minimal) Print queue length
+DefQueueLen equ 10			; 10 files worth
+MinQueueLen equ 4			; 4 files worth min
+MaxQueueLen equ 32			; 32 files worth max.
+
+;----- Maximum length of a file name (incl nul)
+MaxFileLen equ	64
+
+; **************** Bogosity Warning *****************
+;  Below is the equate that MaxFile SHOULD be.	Since the 3.0/3.1 documentation
+;  documents each queue entry as being 64 chars long.  Yes it is known that
+;  that causes Print to misbehave on files deep in trees.  But for
+;  compatibilities sake, IBM insisted that we change the code back to the
+;  way it was.
+;MaxFileLen equ  63 + 2 + 12		 ; 63 characters as Command.com's
+					;	  max. path length
+					; 2  character for the Drive ext.
+					; 12 characters for the max. valid
+					;    DOS filename
+
+
+.xlist
+.xcref
+BREAK	MACRO	subtitle
+	SUBTTL	subtitle
+	PAGE
+ENDM
+
+stdin	    EQU     0
+stdout	    EQU     1
+stderr	    EQU     2
+stdaux	    EQU     3
+stdprn	    EQU     4
+
+	INCLUDE DEVSYM.INC
+	INCLUDE SYSCALL.INC
+	INCLUDE ERROR.INC
+	INCLUDE SYSVAR.INC
+	INCLUDE FIND.INC
+	include dpl.inc
+	INCLUDE PDB.INC
+	INCLUDE SYSCALL.INC
+	INCLUDE MI.INC
+	include versiona.inc
+.list
+.cref
+
+
+error_busy		EQU	9
+error_queue_full	EQU	8
+error_name_too_long	EQU	12
+
+IF1
+	IF	IBM
+	%out	IBM VERSION
+	ELSE
+	%out	MS-DOS VERSION
+	ENDIF
+ENDIF
+
+BREAK	<Segment Definitions>
+
+
+CodeR	Segment public para
+CodeR	EndS
+
+Code	Segment public para
+Code	EndS
+
+Data	Segment public byte
+Data	EndS
+
+Stack	Segment Stack
+Stack	Ends
+
+DG	group	Code,Data,Stack
+
+SaveReg MACRO	reglist 		;; push those registers
+IRP reg,<reglist>
+	PUSH	reg
+ENDM
+ENDM
+.xcref	SaveReg
+
+RestoreReg  MACRO   reglist		;; pop those registers
+IRP reg,<reglist>
+	POP	reg
+ENDM
+ENDM
+

SRC/CMD/PRINT/PRINT.LNK

@@ -0,0 +1,2 @@
+PRINT_RM PRINT_R PRINT_T PRINT_TM NPRINTF
+PRINT.EXE /m;

SRC/CMD/PRINT/PRINT_RM.ASM

@@ -0,0 +1,34 @@
+;	SCCSID = @(#)print_rmes.asm	4.1 85/07/17
+	INCLUDE pridefs.inc
+
+
+BREAK	<Resident Portion Messages>
+
+;
+;	MSDOS V3.00 PRINT
+;
+;	Resident Portion Messages
+;
+;	02/15/84	MAU	Created as a separate link module
+;				from the include file. should
+;				always be linked first!!
+;
+
+CodeR	Segment public para
+
+	public	ERRMES, ERRMEST, BELMES, ErrMesT2, CanMes, CanFilNAm
+	public	AllCan, ERR0, ERR1, ERR2, ERR3, ERR4, ERR5, ERR6,
+	public	ERR7, ERR8, ERR9, ERR10, ERR11, ERR12, FATMES
+	public	BADDRVM, BADMES, badmeslen, GOODMES, goodmeslen
+
+;INT 24 messages A La COMMAND
+Public PRMES001S, PRMES001E
+PRMES001S	equ	$
+
+include print_rm.inc
+
+PRMES001E	equ $
+
+CodeR	EndS
+
+	End

SRC/CMD/PRINT/PRINT_RM.INC

@@ -0,0 +1,34 @@
+
+ERRMES		DB	13,10,13,10,"**********",13,10,"$"
+ERRMEST 	DB	" error reading file",13,10,"$"
+BELMES		DB	13,0CH,7,"$"
+
+ErrMesT2	db	"File not found",13,10,"$"
+
+CanMes		DB	13,10,13,10,"File $"
+CanFilNam	DB	" canceled by operator$"
+
+AllCan		DB	13,10,13,10,"All files canceled by operator$"
+
+ERR0		DB	"Write protect$"
+ERR1		DB	"Bad unit$"
+ERR2		DB	"Not ready$"
+ERR3		DB	"Bad command$"
+ERR4		DB	"Data$"
+ERR5		DB	"Bad call format$"
+ERR6		DB	"Seek$"
+ERR7		DB	"Non-DOS disk$"
+ERR8		DB	"Sector not found$"
+ERR9		DB	"No paper$"
+ERR10		DB	"Write fault$"
+ERR11		DB	"Read fault$"
+ERR12		DB	"Disk$"
+
+FATMES		DB     "File allocation table bad drive "
+BADDRVM 	DB     "A.",13,10,"$"
+
+BADMES		DB	"List output is not assigned to a device",13,10
+badmeslen	dw	$-badmes
+GOODMES 	DB	"Resident part of PRINT installed",13,10
+goodmeslen	dw	$-goodmes
+