Category : C Source Code
Archive   : CEXPRESS.ZIP
Filename : STRLINEB.ASM

;void string_line_b(strg,dir,col,row,length,color);
; unsigned char *strg,dir,col,row,length,color;

EXTRN _memory_model:byte
EXTRN _video_page:byte

_TEXT SEGMENT BYTE PUBLIC 'CODE'
ASSUME CS:_TEXT
PUBLIC _string_line_b
_string_line_b proc near
push bp ;
mov bp,sp ;set stack frame
push di ;
push si ;
cmp _memory_model,0 ;near or far?
jle begin ;jump if near
inc bp ;else add 2 to BP
inc bp ;
begin: push ds ;save DS
mov bh,_video_page ;set video page
cmp _memory_model,2 ;data near or far?
jb L0 ;jump if near
lds si,dword ptr[bp+4] ;DS:SI pts to Strg
inc bp ;add 2 to BP since dword ptr
inc bp ;
jmp short L00 ;
L0: mov si,[bp+4] ;
L00: mov [bp+4],si ;move Strg ptr in FAR case
mov dl,[bp+8] ;Col in DL
dec dl ;count from 0
mov dh,[bp+10] ;Row in DH
dec dh ;count from 0
mov ah,2 ;function to set cursor
int 10h ;set cursor to line
sub cx,cx ;
mov cl,[bp+12] ;string length in DI
mov di,cx ;

or di,di ;test for zero
jz L6 ;quit if zero
mov bl,[bp+14] ;attribute in BL
cmp byte ptr[si],0 ;test for null string
je L6 ;
mov cx,1 ;number chars to write in function
L1: mov al,[si] ;get char from Strg
inc si ;forward Strg ptr for next time
cmp al,0 ;end of Strg?
jne L2 ;jump if not
mov si,[bp+4] ;set ptr back to start
jmp short L1 ;restart
L2: mov ah,9 ;function to write char
int 10h ;write it
dec di ;dec length counter
or di,di ;zero yet?
jz L6 ;quit if zero
L3: mov ah,[bp+6] ;get direction param
cmp ah,'V' ;write vertically?
je L4 ;jump ahead if so
cmp ah,'v' ;test for small 'v'
je L4 ;jump if small 'v'
inc dl ;inc col number
jmp short L5 ;jump ahead
L4: inc dh ;inc row number
L5: mov ah,2 ;function to set cursor
int 10h ;reset cursor
jmp short L1 ;go write next
L6: pop ds ;
pop si ;
pop di ;
pop bp ;
cmp _memory_model,0 ;quit
jle quit ;
db 0CBh ;RET far
quit: ret ;RET near
_string_line_b endp
_TEXT ENDS
END