Category : Assembly Language Source Code
Archive   : RHSTDLIB.ZIP
Filename : PUTC.ASM

stdlib segment para public 'slcode'
assume cs:stdlib
;
;
PutcAdrs dd sl_putcstdout
PutcStkIndx dw 0
PutcStk dd 16 dup (sl_putcstdout)
PSIsize = $-PutcStk
;
;
; Putc- Sends the character in AL to the current output routine.
; By default, this is "putstdout". PutcAdrs contains the address of the
; current output routine.
;
public sl_putc
sl_putc proc far
jmp dword ptr cs:PutcAdrs
sl_putc endp
;
;
;
;
; PutCR- Prints a new line to the standard output device.
;
public sl_putcr
sl_putcr proc far
push ax
mov al, 13 ;Carriage return
call dword ptr cs:PutcAdrs
mov al, 10 ;Line feed
call dword ptr cs:PutcAdrs
pop ax
ret
sl_putcr endp
;
;
;
; PutStdOut- Prints the character in AL to the standard output device by
; calling DOS to print the character.
;
public sl_putcstdout
sl_putcstdout proc far
push ax
push dx
mov dl, al
mov ah, 2
int 21h
pop dx
pop ax
ret
sl_putcstdout endp
;
;
; PutcBIOS- Prints the character in AL by calling the BIOS output routine.
;
public sl_PutcBIOS
sl_PutcBIOS proc far
push ax
mov ah, 14
int 10h
pop ax
ret
sl_PutcBIOS endp
;
;
; GetOutAdrs- Returns the address of the current output routine in ES:DI.
;
public sl_GetOutAdrs
sl_GetOutAdrs proc far
les di, cs:PutcAdrs
ret
sl_GetOutAdrs endp
;
;
; SetOutAdrs- Stores the address in ES:DI into PutcAdrs. This must be the
; address of a valid output routine which outputs the character
; in the AL register. This routine must preserve all registers.
;
public sl_SetOutAdrs
sl_SetOutAdrs proc far
mov word ptr cs:PutcAdrs, di
mov word ptr cs:PutcAdrs+2, es
ret
sl_SetOutAdrs endp
;
;
;
; PushOutAdrs- Pushes the current output address onto the output stack
; and then stores the address in es:di into the output address
; pointer. Returns carry clear if no problems. Returns carry
; set if there is an address stack overflow. Does NOT modify
; anything if the stack is full.
;
public sl_PushOutAdrs
sl_PushOutAdrs proc far
push ax
push di
cmp cs:PutcStkIndx, PSIsize
jae BadPush
mov di, cs:PutcStkIndx
add cs:PutcStkIndx, 4
mov ax, word ptr cs:PutcAdrs
mov word ptr cs:PutcStk[di], ax
mov ax, word ptr cs:PutcAdrs+2
mov word ptr cs:PutcStk+2[di], ax
pop di
mov word ptr cs:PutcAdrs, di
mov word ptr cs:PutcAdrs+2, es
pop ax
clc
ret
;
BadPush: pop di
pop ax
stc
ret
sl_PushOutAdrs endp
;
;
; PopOutAdrs- Pops an output address off of the stack and stores it into
; the PutcAdrs variable.
;
public sl_PopOutAdrs
sl_PopOutAdrs proc far
push ax
mov di, cs:PutcStkIndx
sub di, 4
jns GoodPop
;
; If this guy just went negative, set it to zero and push the address
; of the stdout routine onto the stack.
;
xor di, di
mov word ptr cs:PutcStk, offset sl_PutcStdOut
mov word ptr cs:PutcStk+2, seg sl_PutcStdOut
;
GoodPop: mov cs:PutcStkIndx, di
mov es, word ptr PutcAdrs+2
mov ax, word ptr cs:PutcStk+2[di]
mov word ptr cs:PutcAdrs+2, ax
mov ax, word ptr cs:PutcStk[di]
xchg word ptr cs:PutcAdrs, ax
mov di, ax
pop ax
ret
sl_PopOutAdrs endp
;
stdlib ends
end