Category : Dbase (Clipper, FoxBase, etc) Languages Source Code
Archive   : ASMCLIP.ZIP
Filename : PR_STAT.ASM

;
;****************************************************************
; *
; CLIPPER ROUTINE - PRINTER STATUS ( PARALLEL ) *
; By Kelly Mc Tiernan *
; *
;****************************************************************
;
;
; This routine is to be called to determine the current status
; of the printer on IBM compatables. This routine is a simple
; go / no - go status report. Its usefullness stems from the
; fact that program termination to the operating system can
; be avoided. i.e. - instead of DOS error, provide internal
; program error message. Ignoring error will return to the
; application instead of DOS. Call with a single byte string
; as a parameter. Returned in this string will be:
;
; 0 = ON LINE, READY
; 1 = PRINTER OFF LINE OR NOT READY
;
; Note: This routine assumes parallel port 1.
;
; e.g. - STATUS = " "
; CALL PRSTAT WITH STATUS
;
PUBLIC prstat
;
CHECK EQU 2 ; status check command
PNUM EQU 0 ; parallel port 1
PRNT EQU 17h ; bios printer interupt
REDY EQU 90h ; printer ready
;
_PROG SEGMENT BYTE
ASSUME CS:_PROG
;
prstat PROC FAR
push bp ; standard setup, param's
mov bp,sp ;
push es ;
les di,dword ptr [bp + 6] ; address of return status byte
mov ah,CHECK ; status check
mov dx,PNUM ; port 1
int PRNT ;
mov al,'0' ; returned if O.K.
cmp ah,REDY ; ready ?
jz done ; yes
inc al ; ascii 1
done:
stosb ; place return byte
pop es ; restore state
pop bp ;
ret
prstat ENDP
_PROG ENDS
END