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Assembly Source File | 1987-06-15 | 16.6 KB | 612 lines

page 58,132 title NEWPRN Copyright (c) 1986,87 COMPAQ Computer Corp. ;****************************************************************************** ; ; Name: NEWPRN ; ; Group: DRIVER ; ; Revision: 1.10 ; ; Date: June 15, 1987 ; ; Author: M P Vaughan ; ;****************************************************************************** ; ; Changes: ; ; DATE REVISION DESCRIPTION ; -------- -------- ------------------------------------------------------ ; 12/15/86 1.00 Original. Adapted from PRINTER.ASM from REV F 386 ; system ROM for installation as the INT 17h function for ; 386. ; 6/15/87 1.10 Shorten delay for recovery, and insert printer busy ; test in wait_milli. MPV ;****************************************************************************** ; ; Functional Description: ; ; This module replaces INT 17h for the 386. This is all of the parallel ; printer functions. It is a patch for use with high capacity ; printers such as the HP Laserjet. The delays for the original INT 17h ; function sent the routine off into a 1ms delay to wait for the printer ; to become ready after it was busy. This routine inserts a check for ; printer busy (prn_busy) within the 1ms delay routine. If the printer ; becomes ready while still in the wait routine, PRN_BUSY will force an ; exit to print the routine. This lowers the delay when a full 1ms is ; not required for delay. ; ; jmp $+2 ; Changed to the following ; jmp $+2 ; ; ______________________ ; ; call delay ; . . ; . . ; . . ; delay proc near ; push cx ; mov cx,0Fh ; this_one: ; loop this_one ; pop cx ; ret ; delay endp ; ;****************************************************************************** ; ;****************************************************************************** ; ; Equates ; ;****************************************************************************** ; STANDARDOUT equ 01h LSR equ 5 ; line status register DOS equ 21h ; ;****************************************************************************** ; ; Externals ; ;****************************************************************************** ; extrn prntbase:word ; printer base addrs table extrn printtmo:byte ; table of timeout values extrn ram400:byte ; ram segment page ; dev segment byte public 'DEV' assume cs:dev,ds:seg ram400 ; ;****************************************************************************** ; ; dev_head ; ;****************************************************************************** ; org 000h ; Devices have no psp, so start at 0h ; devhead label word dw -1, -1 ; Pointer to next device - must be set ; to -1 dw 8000h ; Attributes - this is a char device dw strategy ; pointer to device strategy entry pt. dw entry ; pointer to device interrupt entry pt. db 'newprn ' ; Character device name field ; ;****************************************************************************** ; ; Command Jump Tables ; devtbl label word dw dev$init dw exit ; Block device only dw exit ; Block device only dw exit ; IOCNTL input dw exit ; Input (read) dw exit ; Non-destructive input no wait (Char) dw exit ; Input status (char only) dw exit ; Input flush (char only) dw exit ; Output (write) dw exit ; Output (write) with verify dw exit ; Output status (char only) dw exit ; Output flush (char only) dw exit ; IOCNTL output page ;****************************************************************************** ; ; Device entry point ; ; Strategy ; ptrsav dd 0 ; stratp proc far ; strategy: mov word ptr [ptrsav],bx mov word ptr [ptrsav+2],es ret stratp endp ; ;****************************************************************************** ; ; Main entry point cmdlen = 0 ; Command Length unit = 1 ; Unit number cmdcode = 2 ; Command Code status = 3 ; Status reservd = 5 ; 8 bytes reserved unitnum = 13 ; unit number of device brk_add = 14 ; Break address (transfer address) entry: push ax push bx pushf lds bx,cs:[ptrsav] ; Pointer to request header mov al,byte ptr [bx].cmdcode cmp al,0 ; Is the command initialize? jne exit ; N: Exit - there are no other fctns jmp dev$init ; Y: Do initialization - install the ; new keyboard buffer. page ;****************************************************************************** ; ; Exit - this is the exit routine for this driver. ; exitp proc far exit: popf pop bx pop ax ret exitp endp ; ;****************************************************************************** page ;****************************************************************************** ;****************************************************************************** ; ; Replacement INT 17h function. ; ;****************************************************************************** ; ; ; ; ;****************************************************************************** ; ; Name: printer - Printer Routine INT 17 ; ; Group: ROM ; ; Revision: A ; ; Date: May 25, 1986 ; ; Author: Lance Pontiff ; ;****************************************************************************** ; ; CHANGES: ; ; DATE REVISION DESCRIPTION ; -------- -------- ------------------------------------------------------ ; 05/25/86 original Adapted from DeskPro 286 Rev E ROM. ; ;****************************************************************************** page ;****************************************************************************** ; ; FUNCTIONAL DESCRIPTION: ; ; Interrupt 17 -- printer output ; ; (AH) = 0 Routine will print the character in (AL). ; Returns the printer status in (AH). Bit 0 set ; to a 1 if character could not be printed. ; (AH) = 1 Initializes the printer port. ; Returns with the printer status in (AH). ; (AH) = 2 Returns with the printer status in (AH). ; ; BITS FUNCTION ; ------ --------------------------------- ; 7 READY ; 6 ACKNOWLEDGE ; 5 OUT OF PAPER ; 4 SELECTED ; ; 3 I/O ERROR ; 2 ; 1 ; 0 TIME OUT ; ; (DX) Set to printer to be used (0, 1, 2). ; ;****************************************************************************** page ; ; Publics ; printer proc near ; printer i/o routine sti ; enable interrupts push bx ; save registers push cx ; push dx ; push si ; save index register push ds ; save segment registers mov bx,seg ram400 ; setup ds register ... mov ds,bx ; to point to bios ram ; ; Setup dx to point to printer by ; indexing printer base table by printer number ; and dx,3 ; force 0,1,2,3 only mov si,dx mov bl,[printtmo+si] ; bl=timeout interval shl si,1 ; make word index mov dx,[prntbase+si] ; dx = printer base or dx,dx ; Q: printer base of zero? ; jz print_ret ; Y: ignore if zero jz _leave ; Y: Exit - print_ret is too far so do ; an intermediate jump (MPV 1.1) ; Check ah register and go to correct routine ; ; ah = 0 print character ; ah = 1 initialize printer ; ah = 2 status ; push ax ; save character test ah,ah ; Q: print char? jz print_it ; Y: dec ah ; Q: initialize printer? jz print_init ; Y: dec ah ; Q: get printer status? jz print_stat ; Y: pop ax ; N: ignore call _leave: jmp short print_ret page ;****************************************************************************** ; Print a character routine ; ; Outputs character to 8 bit register ; Checks busy and waits if needed ; Strobes character into printer ; Then goes to status ; ; ENTRY - AL = character ; BL = timeout value (0.780 sec per count) ; DX = printer base i/o address ; EXIT - BH = status ;------------------------------------------------------------------------------ print_it: out dx,al ; output ascii to printer inc dx ; point to status to check busy jmp $+2 jmp $+2 ; Allow for recovery time ; call delay ; allow recovery time in al,dx ; get printer status and al,0f8h ; Q: printer ready? js prtchr ; Y: go strobe data push ax ; N: protect ax mov ax,90feh ; printer Device Wait clc ; default = ROM timeout int 15h ; Q: Device Wait performed? pop ax ; restore ax jc timeout ; Y: a_count: mov cx,780 ; wait 1 milliseconds 780 times normal_to: push bx ; N: protect bx mov bx,1 ; wait 10 milliseconds call wait_milli ; pop bx ; restore bx in al,dx ; al = printer status and al,0f8h ; Q: printer ready? js prtchr ; Y: go strobe character loop normal_to ; N: keep waiting dec bl ; Q: finished all counts? jnz a_count ; N: timeout: ; Y: jmp $+2 ; Allow for recovery time jmp $+2 ; call delay ; allow recovery time in al,dx ; get printer status and al,0f8h ; Q: printer still busy? js prtchr ; N: go strobe character or al,1 ; Y: set time out bit jmp short print_exit ; exit & post status prtchr: inc dx ; strobe status in al,dx ; read current settings and al,1eh ; or al,01h ; set strobe bit jmp $+2 ; Allow for recovery time jmp $+2 ; call delay ; allow recovery time out dx,al ; turn strobe on and al,1eh ; turn strobe off jmp short print_inits ; page ;****************************************************************************** ; Initialize printer ; ; ENTRY - DX = printer i/o base address ; EXIT - BH = status ;------------------------------------------------------------------------------ print_init: inc dx ; get address of init bit inc dx ; mov al,8 ; initialize latch to slctn jmp $+2 ; Allow for recovery time jmp $+2 ; call delay ; allow recovery time out dx,al ; 'init' line low, select high mov bx,5 ; assert init 5 ms per centronics call wait_milli ; wait 5 milliseconds or al,4 ; set 'init' bit high print_inits: jmp $+2 ; Allow for recovery time jmp $+2 ; call delay ; allow recovery time out dx,al ; dec dx ; get current status dec dx ; point to printer i/o base ; fall into 'print_stat' page ;****************************************************************************** ; Status ; ; ENTRY - DX = printer i/o base address ; EXIT - AL = status ;------------------------------------------------------------------------------ print_stat: inc dx ; point to status jmp $+2 ; Allow for recovery time jmp $+2 ; call delay ; allow recovery time in al,dx ; input status and al,0f8h ; mask unwanted bits ; fall into 'print_exit' ;***************************************************************************** ; ENTRY - AL = masked status from port ; EXIT - AH = status ;------------------------------------------------------------------------------ print_exit: xor al,48h ; invert sense of ack and err mov bh,al ; temp = al pop ax ; restore al, in particular mov ah,bh ; ah = temp print_ret: pop ds ; restore segment registers pop si ; restore index registers pop dx ; restore registers pop cx ; pop bx ; iret ; *** RETURN *** printer endp include pop_f.mac ; Macro to simulate POPF instruction. public wait_milli ; Wait # of milliseconds in BX. ; COUNTS_MILLI = 1192*2 ; System timer counts per millisecond. K16 DW 16 ; ROM constant for hex conversions. ; Equates ; include asciidef.equ ; ASCII defs. ; include ppi_def.equ ; 8255 PPI equates. ; include cnt_def.equ ; 8253 counter-timer equates. ; include vdu_def.equ ; VDU equates. ; ;****************************************************************************** ; ; Delay Routines: ; ; NOTE: These routines has been modified for the 286-based products ; to be processor-speed independent. Note that this routine ; assumes that stack is available. Stack is needed to do POPF ; equivalent. ; ; REG.USED: BX ;****************************************************************************** ; ; This routine delays the number of milliseconds specified in BX. ; wait_milli proc near push bp ; Save BP for caller. push ax ; Save AX for caller. push cx ; Save CX for caller. call delay_ms_sp ; Use routine with stack. pop cx ; pop ax ; pop bp ; ret ; *** RETURN *** wait_milli endp ; page ;****************************************************************************** ; ; DELAY_MS_SP - Routine to delay 1 millisecond per count in BX. ; ; ENTRY - BX = # of Milliseconds ; BP = Return address ; ; EXIT - None ; ; NOTE: This routine has been modified for the 286-based products ; to be processor-speed independent. It assumes that the stack ; is available so that it can run the POP_F macro to preserve ; interrupt status the same as the caller. ; ; REG.USED: AX, BX, CX, BP ;****************************************************************************** delay_ms_sp proc near ; mov cx,bx ; cx= number of milliseconds rd_ini_count: ; pushf ; cli ;;; mov al,LATCH_CNT0 ;;; Latch count for system timer. out cnt_mode,al ;;; in al,cnt_0 ;;; Read low byte first. mov ah,al ;;; jmp $+2 ;;; jmp $+2 ;;; in al,cnt_0 ;;; Read high byte. pop_f ;;; xchg al,ah ; Get bytes in the right order. mov bx,ax ; Save BX=initial count. rd_count: ; call prn_busy ; Q: Is the printer ready? (MPV 1.1) js _exit ; Y: Exit and print it. pushf ; N: Delay a little longer. (MPV 1.1) cli ;;; mov al,LATCH_CNT0 ;;; Latch count for system timer. out cnt_mode,al ;;; jmp $+2 ;;; jmp $+2 ;;; jmp $+2 ;;; in al,cnt_0 ;;; Read low byte of count. mov ah,al ;;; jmp $+2 ;;; jmp $+2 ;;; in al,cnt_0 ;;; Read high byte of count. pop_f ; xchg al,ah ; Get bytes in the right order. push bx ; Save initial timer count. sub bx,ax ; Initial count - Current count. cmp bx,COUNTS_MILLI ; Q: Reached desired count ? pop bx ; Restore initial timer count. jb rd_count ; No, keep reading count. loop rd_ini_count ; Yes, do more milliseconds. _exit: ret ; delay_ms_sp endp ; page ; delay proc near ; mov cx,0Fh ; (MPV 1.1) ;this_one: ; (MPV 1.1) ; loop this_one ; (MPV 1.1) ret dummy dt ? ; (MPV 1.1) delay endp prn_busy proc near ; (MPV 1.1) push ax in al,dx ; al = printer status and al,0f8h ; Q: printer ready? pop ax ret ; (MPV 1.1) prn_busy endp ; ; ; ;****************************************************************************** ;****************************************************************************** page ;****************************************************************************** ;****************************************************************************** ; ; dev$init - this installs the driver. ; ;****************************************************************************** ; Start NEWPRN.SYS - save registers first, then install the new ; interrupt service routine. ;****************************************************************************** dev$init: push ax push bx push cx push dx push si push di push bp push ds push es pushf ; page ;****************************************************************************** ; Set up a new INT 17h handler ;****************************************************************************** install: assume ds:dev mov ax,cs mov ds,ax ; mov dx,offset printer ; Set new INT 17h interrupt mov ax,2517h int DOS ; ;****************************************************************************** ; All done, print install message and prepare to exit. ;****************************************************************************** mov dx,offset i_msg mov ah,09h int DOS ; lds bx,cs:[ptrsav] mov word ptr [bx].brk_add, offset cs:dev$init mov word ptr [bx].status, 10h mov [bx].brk_add+2,cs ; _done: popf pop es pop ds pop bp pop di pop si pop dx pop cx pop bx pop ax jmp exit page ;****************************************************************************** ; Installation messages ;****************************************************************************** i_msg db CR,LF,' NEWPRN.SYS V1.10 Installed' db CR,LF,'(C) Copyright COMPAQ Computer Corp. 1987' db CR,LF db '$' ; dev ends end