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;/*; * Microsoft Confidential; * Copyright (C) Microsoft Corporation 1988 - 1991; * All Rights Reserved.; */ PAGE ,132 ;AN000; TITLE DOS - GRAPHICS Command - Interrupt 2FH Driver ;AN000; ;AN000;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;AN000;;; DOS - GRAPHICS Command;; ;; ;AN000;;; File Name: GRINT2FH.ASM ;AN000;;; ---------- ;AN000;;; ;AN000;;; Description: ;AN000;;; ------------ ;AN000;;; This file contains the Interrupt 2FH driver. ;AN000;;; ;AN000;;; Documentation Reference: ;AN000;;; ------------------------ ;AN000;;; OASIS High Level Design ;AN000;;; OASIS GRAPHICS I1 Overview ;AN000;;; ;AN000;;; Procedures Contained in This File: ;AN000;;; ---------------------------------- ;AN000;;; INT_2FH_DRIVER - Interrupt 2FH driver ;AN000;;; ;AN000;;; Include Files Required: ;AN000;;; ----------------------- ;AN000;;; GRLOAD.EXT - Externals for profile load ;AN000;;; GRCTRL.EXT - Externals for print screen control ;AN000;;; GRPRINT.EXT - Externals for print modules ;AN000;;; GRCPSD.EXT - Externals for COPY_SHARED_DATA module ;AN000;;; ;AN000;;; External Procedure References: ;AN000;;; ------------------------------ ;AN000;;; Calls next Int 2FH handler in the chain. ;AN000;;; ;AN000;;; Linkage Instructions: ;AN000;;; -------------------- ;AN000;;; Refer to GRAPHICS.ASM ;AN000;;; ;AN000;;; Change History: ;; ---------------;; M001 NSM 1/30/91 New int 10 handler to trap alt-prt-sc select;; calls made by ANSI.SYS. For these calls, we;; we need to reinstall our int 5 handler again;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;AN000; ;; ;AN000; ;; ;AN000;CODE SEGMENT PUBLIC 'CODE' ;; ;AN000; ASSUME CS:CODE,DS:CODE ;; ;AN000; ;; ;AN000; PUBLIC OLD_INT_2FH ;; ;AN000; PUBLIC INT_2FH_DRIVER ;; ;AN000; PUBLIC INT_10H_DRIVER ;; ;AN000; PUBLIC PRT_SCR_2FH_NUMBER ;; ;AN000; PUBLIC RESIDENT_CODE_SEG ;; ;AN000; PUBLIC SHARED_DATA_AREA_PTR ;; ;AN000; ;; ;AN000; ;; ;AN000;.XLIST ;AN000;INCLUDE STRUC.INC ;AN000;INCLUDE GRINST.EXT ;AN000;INCLUDE GRCTRL.EXT ;AN000;INCLUDE GRCPSD.EXT ;AN000;.LIST ;AN000;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;AN000;;; ;AN000;;; Module: INT_2FH_DRIVER ;AN000;;; ;AN000;;; Description: ;AN000;;; Respond to GRAPHICS Int 2FH calls. ;AN000;;; The following calls are handled: ;AN000;;; ;AN000;;; AL = 0 � Install Check ;AN000;;; ;AN000;;; Invoked By: ;AN000;;; INT 2FH instruction. ;AN000;;; ;AN000;;; Modules Called: ;AN000;;; Lower level INT 2FH handlers. ;AN000;;; ;AN000;;; Input Registers: ;AN000;;; Install Check - AH=ACH AL=0 ;AN000;;; ;AN000;;; ;AN000;;; Output Registers: ;AN000;;; Install Check: IF GRAPHICS installed ;AN000;;; AH=FFH AL=FFH ;AN000;;; ES : DI points to Shared Data Area ;AN000;;; ELSE ;AN000;;; AH=ACH AL=0 ;AN000;;; ;AN000;;; Logic: ;AN000;;; IF AH=ACH THEN ;AN000;;; IF AL=0 THEN ;AN000;;; AH,AL := -1 ;AN000;;; ES : DI := SHARED_DATA_AREA_PTR ;AN000;;; ENDIF ;AN000;;; IRET ;AN000;;; ELSE ;AN000;;; IF OLD_INT_2FH is a valid pointer THEN ;AN000;;; Jump to Old Int 2FH ;AN000;;; ELSE ;AN000;;; IRET ;AN000;;; ENDIF ;AN000;;; ENDIF ;AN000;;; ;AN000;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;AN000; ;AN000;INT_2FH_DRIVER PROC NEAR ;AN000; JMP SHORT INT_2FH ;AN000;PRT_SCR_2FH_NUMBER EQU 0ACH ; 2FH Multiplex interrupt number ;AN000; ; assigned to Print Screen. ;AN000;OLD_INT_2FH DD ? ; Pointer to next 2FH interrupt handler ;AN000;RESIDENT_CODE_SEG DW ? ; Segment for installed stuff ;AN000;SHARED_DATA_AREA_PTR DW ? ; Offset of the start of the ;AN000; ; Shared Data Area ;AN000; ;AN000;INT_2FH: ;AN000;;-------------------------------------------------------------------------------;AN000;; Verify if the 2FH Interrupt call is for our interrupt handler: ;AN000;;-------------------------------------------------------------------------------;AN000; .IF <AH EQ PRT_SCR_2FH_NUMBER> AND;If 2FH call is for us ;AN000; .IF <ZERO AL> ; and request is "Get install state" ;AN000; .THEN ; then, ;AN000;;-------------------------------------------------------------------------------;AN000;; Yes: return results ;AN000;;-------------------------------------------------------------------------------;AN000; MOV DI,CS:SHARED_DATA_AREA_PTR ; ES:DI := Pointer to shared ;AN000; PUSH CS:RESIDENT_CODE_SEG ; data area ;AN000; POP ES ; ;AN000; MOV AH,0FFH ; AL and AH := "We are installed" ;AN000; MOV AL,AH ; ;AN000; IRET ; Return to interrupted process ;AN000;;-------------------------------------------------------------------------------;AN000;; No, pass control to next 2FH interrupt handler: ;AN000;;-------------------------------------------------------------------------------;AN000; .ELSE ; else, this call is not for us: ;AN000; .IF <<WORD PTR CS:OLD_INT_2FH> NE 0> AND ;if there is another ;AN000; .IF <<WORD PTR CS:OLD_INT_2FH+2> NE 0> ; 2FH driver ;AN000; .THEN ; below us then, ;AN000; JMP CS:OLD_INT_2FH ; pass control to it ;AN000; .ELSE ; else, there is nobody to pass ;AN000; IRET ; control to, just return. ;AN000; .ENDIF ; END If there is a driver below us.;AN000; .ENDIF ; END If this call is for us. ;AN000;INT_2FH_DRIVER ENDP ;AN000; ;AN000;
;/*M001 BEGIN */;========================================================================; INT_10h_Driver :; int 10 handler to check for alt-prt-sc-select calls (ah=12,bl=20h); Other int 10 calls are passed on. For alt-prt-sc-select calls,; old int 10 is called and after return, we reinstall our int 5 (prt_sc); vector back again ( if it was changed by ANSI.SYS).;=======================================================================INT_10H_DRIVER PROC NEAR
sti ; restore interrupts cmp ah,ALTERNATE_SELECT ; see if the call is for jnz go_old_int10 ; alt_prt_sc; if so cmp bl,ALT_PRT_SC_SELECT ; call int 10 and then jz Set_Our_Int5_handler ; restore out PRT_SC vectorgo_old_int10: ; other int 10 calls jmp DWORD PTR cs:OLD_INT_10H ; ...pass it on.
; the call is for alternate prt Screen int 10; call the old int 10 handler and then restore our int 5 vector back again
Set_Our_Int5_handler: pushf call DWORD PTR cs:OLD_INT_10H ; call the prev.int 10 handler push ax push bx push cx push dx push si push di push ds xor ax,ax mov ds,ax ; ds-> 0 to get at int.vector table mov si,5 * 4 ; ds:si -> ptr to int 5 vector mov cx,cs mov dx,offset PRT_SCR
cli mov ax,ds:[si+2] ; segment for current int 5 vector cmp ax,cx ; is it changed by ROM BIOS je no_int5_chg mov bx,ds:[si] cmp bx, dx ;further sanity check for offset je no_int5_chg
; cx:dx = our int 5 handler; ax:bx = current int 5 handler; store the current int 5 handler as the old handler and install ourselves; again
mov ds:[si],dx ; store offset mov ds:[si+2],cx ; store segment mov CS:[BIOS_INT_5H],bx ; store old int5 vector mov CS:[BIOS_INT_5H +2],ax
no_int5_chg: sti pop ds pop di pop si pop dx pop cx pop bx pop ax
iret
INT_10H_DRIVER ENDP
; /* M001 END */
CODE ENDS ;AN000; END ;AN000;
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