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1991
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monoscrn.asm
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Assembly Source File
|
1991-01-09
|
15KB
|
333 lines
;*******************************************************************************
;| |
;| Module: Monochrome Screen access from Windows 3.0 |
;| |
;| Description: This module demonstrates how to access memory mapped |
;| devices within the Windows environment. |
;| |
;| Author: Chris Schwartz (c) 10/25/90 |
;| |
;*******************************************************************************
.MODEL SMALL
.286
PUBLIC DllInit ;dll entry point
PUBLIC WEP ;dll exit point
PUBLIC VioInit
PUBLIC VioWrtStrAttr
PUBLIC VioMovePointer
PUBLIC VioShowPointer
PUBLIC DpmActiveMode
PUBLIC DpmSelectorFromSegment
extrn __B000H:ABS
.DATA
bogusData dw 8 DUP(0) ;just to keep windows from wigging out
wVideoSeg dw 0
iShowPtrLevel dw 0 ;initially dont display pointer
iRow dw 0
iCol dw 0
iOldAttr dw 0
.CODE
;*******************************************************************************
;| |
;| FAR PASCAL Calling Convention |
;| |
;| BOOL DllInit(VOID); - Dll entry point, called by windows during loading|
;| |
;| Entry Values: DS = Library Data Segment ES = Command Line Sel |
;| DI = Module Handle SI = Command Line Off |
;| CX = Local Heap Size |
;| |
;| Return Values: AX = 0 Failed, don't load |
;| AX != 0 Success, load this puppy. |
;| |
;*******************************************************************************
;-------------------------------------------------------------------------------
DllInit PROC FAR
mov ax, 1 ;load this puppy
ret
DllInit ENDP
;*******************************************************************************
;| |
;| FAR PASCAL Calling Convention |
;| |
;| BOOL WEP(WORD wExitMode); - Dll exit point |
;| |
;| Return Values: AX = 0 Failed Cleanup |
;| AX != 0 Success |
;| |
;*******************************************************************************
;-------------------------------------------------------------------------------
WEP PROC FAR
mov ax, 1 ;goodbye
ret 2
WEP ENDP
;*******************************************************************************
;| |
;| FAR PASCAL Calling Convention |
;| |
;| BOOL DpmActiveMode(VOID); |
;| |
;| Return Values: AX = 0 Protected Mode under DPMI |
;| AX != 0 Real mode, or not under DPMI |
;| |
;*******************************************************************************
;-------------------------------------------------------------------------------
DpmActiveMode PROC FAR
mov ax, 1686h ;DPMI Mode Detection Op Code
int 2Fh ;only changes the AX register
ret
DpmActiveMode ENDP
;*******************************************************************************
;| |
;| FAR PASCAL Calling Convention |
;| |
;| WORD DpmSelectorFromSegment(WORD); |
;| |
;| Return Value: AX = 0 Then function failed, else we have a selector. |
;| |
;*******************************************************************************
;-------------- Formal Parameters ----------------------------------------------
wRealSegment equ [bp+06]
;-------------------------------------------------------------------------------
DpmSelectorFromSegment PROC FAR
push bp
mov bp, sp
mov ax, 02h
mov bx, wRealSegment
int 31h
jnc DpmSFSExit ;return protected mode selector
xor ax, ax ;return error code
DpmSFSExit:
pop bp
ret 2
DpmSelectorFromSegment ENDP
;*******************************************************************************
;| |
;| FAR PASCAL Calling Convention |
;| |
;| VOID VioInit(VOID); |
;| |
;*******************************************************************************
;-------------------------------------------------------------------------------
VioInit PROC FAR
push ds
mov ax, DGROUP
mov ds, ax ;fixup the dll's data segment
mov ax, __B000H
mov wVideoSeg, ax
VioInitExit:
pop ds
ret
VioInit ENDP
;*******************************************************************************
;| AX = row DX = col Return: DX:AX |
;*******************************************************************************
ScreenOffset PROC NEAR
mov bx, ax
mov cx, 6
shl ax, cl
sub cx, 2
shl bx, cl
add ax, bx
add ax, dx
shl ax, 1
mov dx, wVideoSeg
ret
ScreenOffset ENDP
;*******************************************************************************
;| |
;| FAR PASCAL Calling Convention |
;| |
;| VioWrtStrAttr(lpData, wLen, wRow, wCol, lpAttr) |
;| |
;*******************************************************************************
;-------------- Formal Parameters ----------------------------------------------
lpData equ [bp+16]
wLen equ [bp+14]
wRow equ [bp+12]
wCol equ [bp+10]
lpAttr equ [bp+06]
;-------------------------------------------------------------------------------
VioWrtStrAttr PROC FAR
push bp
mov bp, sp
push ds
mov ax, DGROUP
mov ds, ax ;fixup dll's data segment
push es
push di
push si
mov ax, wRow
mov dx, wCol
call ScreenOffset ;returns proper video address
or dx, dx
je VioWrtStrAttrExit
mov es, dx
mov di, ax
mov cx, wLen
lds si, lpAttr
lodsb
mov ah, al
lds si, lpData
VioWrtStrAttrLoop:
lodsb
stosw
loop VioWrtStrAttrLoop ;cook those puppies
VioWrtStrAttrExit:
pop si
pop di
pop es
pop ds
pop bp
ret 14
VioWrtStrAttr ENDP
;*******************************************************************************
;| |
;| FAR PASCAL Calling Convention |
;| |
;| VioMovePointer(wRow, wCol) |
;| |
;*******************************************************************************
;-------------- Formal Parameters ----------------------------------------------
wRow equ [bp+08]
wCol equ [bp+06]
;-------------------------------------------------------------------------------
VioMovePointer PROC FAR
push bp
mov bp, sp
push ds
mov ax, DGROUP
mov ds, ax ;fixup dll's data segment
push es
push di
push si
cmp iShowPtrLevel, 0
jle VMPJustUpdate
;now we need to restore the old attr and update the new location
mov ax, iRow
mov dx, iCol
call InternalHidePointer
mov ax, wRow
mov dx, wCol
xor si, si
call InternalShowPointer
VMPJustUpdate:
mov ax, wRow ;update internal values
mov dx, wCol
mov iRow, ax
mov iCol, dx
VioMovePointerExit:
pop si
pop di
pop es
pop ds
pop bp
ret 4
VioMovePointer ENDP
;*******************************************************************************
;| AX = row DX = col |
;*******************************************************************************
InternalShowPointer PROC NEAR
call ScreenOffset
mov es, dx
inc ax
mov di, ax
mov ax, WORD PTR es:[di]
mov iOldAttr, ax
rol al, 4
stosb
ret
InternalShowPointer ENDP
;*******************************************************************************
;| AX = row DX = col |
;*******************************************************************************
InternalHidePointer PROC NEAR
call ScreenOffset
mov es, dx
inc ax ;move over to attr byte
mov di, ax
mov ax, iOldAttr
stosb
ret
InternalHidePointer ENDP
;*******************************************************************************
;| |
;| FAR PASCAL Calling Convention |
;| |
;| VioShowPointer(bTrueFalse) |
;| |
;*******************************************************************************
;-------------- Formal Parameters ----------------------------------------------
bTrueFalse equ [bp+06]
;-------------------------------------------------------------------------------
VioShowPointer PROC FAR
push bp
mov bp, sp
push ds
mov ax, DGROUP
mov ds, ax ;fixup dll's data segment
push es
push di
push si
mov ax, bTrueFalse
or ax, ax
je VSPDecLevel
inc iShowPtrLevel
cmp iShowPtrLevel, 0
jbe VioShowPointerExit
mov ax, iRow
mov dx, iCol
call InternalShowPointer
jmp SHORT VioShowPointerExit
VSPDecLevel:
dec iShowPtrLevel
cmp iShowPtrLevel, 0
jne VioShowPointerExit
mov ax, iRow
mov dx, iCol
call InternalHidePointer
VioShowPointerExit:
pop si
pop di
pop es
pop ds
pop bp
ret 2
VioShowPointer ENDP
END DllInit
