DGROUP	GROUP	DATA
	Title	'PC DOS Printer Output Module'
;       Revision : Jan. 04, 1984    File : ZPRINTIO.A86   V1.0
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;                                                                            ;
;  Printer_out : Output through ROM BIOS routines (INT 17) to printer        ;
;                This Routine Displays an error message on the console       ;
;                if the char. cannot be printed.                             ;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
	Dseg
; This port may be patched by Graphics Install Utility 
; to redirect the printer port (0, 1, 2) for a traget system

	Extrn	Print_port:word
	Extrn	Abort_flg:byte

Print_err	Db	'Printer Time Out Error',0Ah, 0Dh, '$'

Print_io	Equ	17H	; ROM BIOS entry point, Software Interrupt 17h 
BDOS		Equ	224	; BDOS Function Call

	Cseg
	PUBLIC	Printer_out, Pout

;----------------------------------------------------------------------------+
; Printer_out                                                                +
;	Output to Printer, Cx points to the No. of bytes to output           +
;	Followed by the data string                                          +
;                                                                            +
;  Input                                                                     +
;       <Cx> = Address of the Count and the Data String to output            +
;  Registers   Cx is modified                                                +
;              All others unchanged                                          +
;                                                                            +
;----------------------------------------------------------------------------+

Printer_Out:
;	Save Registers
	Push	Ax
	Push	Bx
	Push	Dx
	Push	Es
	Mov	Bx, Cx
	Mov	Cl, Byte Ptr [BX]	; No. of Byte to Output
Out:	Push	Cx
	Inc	Bx
	Push	Bx
	Mov	Al, Byte Ptr [Bx]
	Mov	Ah, 0			; Print the Char. in <Al>
	Mov	Dx, Print_Port		; Output Printer Port
	Int	Print_io
	And	Ah, 00101001B		; If the Char. can not be printed,
	Jz	Pj1			; <Ah> = xxxxxxx1 (Time Out).
					; <Ah> = xx1xxxxx (Out of Paper).
					; <Ah> = xxxx1xxx (I/O Error).	
;;;;;	Mov	Byte Ptr Abort_flg, 0ffH	; Set Abort Flag
;	Output Printer Time Out Message
	Mov	Dx, (Offset Print_err)
	Mov	Cl, 09			; Output error message to Console
	Int	BDOS
Pj1:	Pop	Bx
	Pop	Cx
	Dec	Cl
	Jnz	Out
;	Restore Registers
	Pop	Es
	Pop	Dx
	Pop	Bx
	Pop	Ax
	RET

;----------------------------------------------------------------------------+
;                                                                            +
;  POUT: Output a byte in <Dl> Through Rom Bios Printer Io Function          +
;                                                                            +
;  Input :  <Dl> = Data byte                                                 +
;  Output:  Printer Port                                                     +
;  Registers   All Changed, Caller must save it's own registers              +
;                                                                            +
;----------------------------------------------------------------------------+
POUT:
	Mov	Al, Dl
	Mov	Ah, 0
	Mov	Dx, Print_Port		; Output Printer Port
	Int	Print_io		; Output Byte to Printer
					; Through Rom BIOS function
	Ret

	End