Category : Batch File Utilities - mostly for DOS
Archive   : BATTUTOR.ZIP
Filename : QDISPLAY.INC

;
; qdisplay.inc
;
; if CX = 0 (null string), then force one blank into string.
;
; This is because we want to avoid col. 1 for the reverse video box
; display. If this program looses control (by control-break or
; critical error, for example) while the reverse video prompt box is
; in col. 1, then BIOS scroll procedures will propagate the reverse
; video attribute to the new line each time the screen is scrolled
; by DOS.
;
MOV AH,2 ;DOS fn call, 1 char display
OR CL,CL ;is byte count of string zero?
JNE DISPLAY_LINE ;jump if not
INC CL ;incr count to 1
MOV BYTE PTR [SI+1],BLANK_CHAR ;put 1 blank char in string
MOV BX,1 ;point BX to this char
;
; display line. Use one-character DOS call, because the "display
; string" call won't display "$"
;
DISPLAY_LINE: MOV DL,[SI][BX] ;next char into DL
INT 21H ;call DOS
INC BX ;point to next char
LOOP DISPLAY_LINE ;and loop on char count
;
; -------- end of qdisplay.inc --------
;
 ;"display one char" DOS call
INT 21H ;call DOS