page 60,132
title AuxDrv - Monochrome AUX driver
;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
; This device directs AUX output to the Monochrome display, and AUX input to
; the BIOS. At boot time, it saves the vectors for INT 9 and INT 16h, and
; when AUX input is requested temporarily restores them. So, it can be used
; for AUX input and output from inside Windows.
; You should still use the /M option with SymDeb rather than /"=AUX", because
; SymDeb has a bug where it puts out memory allocation messages to CON even
; though you said /"=AUX".
; It's also handy in DOS; you can do, for example, TYPE FOO >AUX and it will
; go to the Monochrome screen. You can even say CTTY AUX if you don't feel
; like saying MODE MONO...
; In case you're wondering why the screen output code is so simple (i.e. there
; is no "current row" variable), it always outputs to the last row of the
; screen, instead of starting at the top. Don't laugh, it works fine and made
; it easier to code this pup.
; This driver is in the public domain. If you find it useful, how about
; returning the favor and putting some of your own favorite utilities in
; the public domain, too? (***with source code!!!***)
; Michael Geary (GEnie: GEARY; BIX: GEARY; CompuServe: 76146,42)
;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
; request header entries
cmdCode equ 2
status equ 3
ndInputChar equ 13
brkOff equ 14
brkSeg equ brkOff+2
xferOff equ 14
xferSeg equ xferOff+2
xferCount equ 18
; constants
BS equ 08h
TAB equ 09h
LF equ 0Ah
CR equ 0Dh
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Zseg segment at 0
org 9*4
KbdInt label dword
KbdIntOff dw ?
KbdIntSeg dw ?
org 16h*4
KbdBios label dword
KbdBiosOff dw ?
KbdBiosSeg dw ?
Zseg endS
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Cseg segment para public 'code'
assume cs:Cseg, ds:nothing, es:nothing
begin:
; device driver header
nextDev dd -1
attribute dw 1000100000000000b
strategy dw devStrategy
interrupt dw devInt
devName db 'AUX '
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rhAddr label dword
rhOff dw ?
rhSeg dw ?
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funTab label word
dw init
dw mediaCheck
dw buildBpb
dw ioCtlIn
dw input
dw ndInput
dw inStat
dw inFlush
dw output
dw outVerify
dw outStat
dw outFlush
dw ioCtlOut
dw open
dw close
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scrMinOff equ 160*24
scrMaxOff equ 160*25
scrCurOff dw scrMinOff
dw 0B000h
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SaveKbdInt label dword
SaveKbdIntOff dw 0
SaveKbdIntSeg dw 0
SaveKbdBios label dword
SaveKbdBiosOff dw 0
SaveKbdBiosSeg dw 0
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devStrategy:
mov cs:rhSeg, es
mov cs:rhOff, bx
retf
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devInt:
pushf
push ds
push es
push ax
push bx
push cx
push dx
push di
push si
cld
les bx, cs:rhAddr
mov al, es:[bx].cmdCode
shl al, 1
lea di, funTab
xor ah, ah
add di, ax
jmp word ptr[di]
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outVerify:
output:
mov cx, es:[bx].xferCount ; CX = # bytes to write
lds si, es:[bx].xferOff ; DS:SI --> text
les di, dword ptr scrCurOff
outLoop:
lodsb
cmp al, CR
ja outChar
je outCR
cmp al, LF
je outLF
cmp al, TAB
je outTAB
cmp al, BS
je outBS
outChar:
stosb
inc di
cmp di, scrMaxOff
jb outDone
mov di, scrMinOff
outLF:
push ds
push es
push si
push di
push cx
mov ax, es
mov ds, ax
xor di, di ; Scroll screen
mov si, 160
mov cx, 24*80
rep movsw
mov ax, 0720h ; Blank bottom line
mov cx, 80
rep stosw
pop cx
pop di
pop si
pop es
pop ds
jmp outDone
outBS:
cmp di, scrMinOff
je outDone
sub di, 2
jmp outDone
outTAB:
or di, 0Eh
jmp outDone
outCR:
mov di, scrMinOff
outDone:
loop outLoop
mov scrCurOff, di
mov dx, 3B4h
shr di, 1 ; Set cursor position
mov ax, di
mov al, 0Eh
out dx, ax
mov ax, di
xchg ah, al
mov al, 0Fh
out dx, ax
jmp exit
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input:
call SetOldKbdInts
mov ah, 0
int 16h
les di, es:[bx].xferOff ; ES:DI --> text
stosb
mov byte ptr es:[bx].xferCount, 1
call SetNewKbdInts
jmp exit
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ndInput:
call SetOldKbdInts
mov ah, 1
int 16h
jz ndInputNone
mov es:[bx].ndInputChar, al
call SetNewKbdInts
jmp exit
ndInputNone:
call SetNewKbdInts
les bx, rhAddr
or word ptr es:status[bx], 0300h ; set busy flag
jmp exit1
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inStat:
call SetOldKbdInts
mov ah, 1
int 16h
jz ndInputNone
call SetNewKbdInts
jmp exit
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inFlush:
call SetOldKbdInts
inFlushLoop:
mov ah, 1
int 16h
jz inFlushDone
mov ah, 0
int 16h
jmp inFlushLoop
inFlushDone:
call SetNewKbdInts
jmp exit
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open:
mov dx, 3B4h ; Set standard monochrome cursor
mov ax, 0B0Ah
out dx, ax
mov ax, 0C0Bh
out dx, ax
close:
jmp exit
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mediaCheck:
buildBpb:
ioCtlIn:
ioCtlOut:
outStat:
outFlush:
exit:
les bx, rhAddr
or word ptr es:status[bx], 0100h
exit1:
pop si
pop di
pop dx
pop cx
pop bx
pop ax
pop es
pop ds
popf
retf
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SetOldKbdInts:
push es
push ax
xor ax, ax
mov es, ax
assume es:Zseg
CLI
mov ax, SaveKbdIntOff
xchg ax, KbdIntOff
mov SaveKbdIntOff, ax
mov ax, SaveKbdIntSeg
xchg ax, KbdIntSeg
mov SaveKbdIntSeg, ax
mov ax, SaveKbdBiosOff
xchg ax, KbdBiosOff
mov SaveKbdBiosOff, ax
mov ax, SaveKbdBiosSeg
xchg ax, KbdBiosSeg
mov SaveKbdBiosSeg, ax
STI
pop ax
pop es
assume es:nothing
ret
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SetNewKbdInts:
push es
push ax
xor ax, ax
mov es, ax
assume es:Zseg
CLI
mov ax, SaveKbdIntOff
mov KbdIntOff, ax
mov ax, SaveKbdIntSeg
mov KbdIntSeg, ax
mov ax, SaveKbdBiosOff
mov KbdBiosOff, ax
mov ax, SaveKbdBiosSeg
mov KbdBiosSeg, ax
STI
pop ax
pop es
assume es:nothing
ret
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init: ; everything from here on is discarded
push es
xor ax, ax
mov es, ax
assume es:Zseg
mov ax, KbdIntOff
mov SaveKbdIntOff, ax
mov ax, KbdIntSeg
mov SaveKbdIntSeg, ax
mov ax, KbdBiosOff
mov SaveKbdBiosOff, ax
mov ax, KbdBiosSeg
mov SaveKbdBiosSeg, ax
pop es
assume es:nothing
mov es:brkSeg[bx], cs
mov es:word ptr brkOff[bx], offset init
jmp exit
;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Cseg endS
end begin
