Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uflorida!gatech!emcard!stiatl!todd
From: todd@stiatl.UUCP (Todd Merriman)
Newsgroups: comp.sys.ibm.pc
Subject: Re: LPT rerouting - can it be done?
Message-ID: <3783@stiatl.UUCP>
Date: 15 Mar 89 13:06:59 GMT
References: <235@alux2.ATT.COM>
Reply-To: todd@stiatl.UUCP (Todd Merriman)
Distribution: usa
Organization: Sales Technologies Inc., Atlanta, GA
Lines: 112

In article <235@alux2.ATT.COM> wg@alux2.ATT.COM (Bill Gieske) writes:
>
>Can I get LPT1: output to go to LPT2: ...........


ifdef DOCUMENTATION
; ****************************************************************************
.MODULE           LPT_SWAP
.LIBRARY          CLIB
.TYPE             function
.DESCRIPTION
   Swap the mapping to LPT1 and LPT2
.ARGUMENTS
   void lpt_swap()
.NARRATIVE
   Lpt_swap swaps the LPT1 and LPT2 definitions.
.APPLICATION      system
.SYSTEM           msdos
.RETURNS
   Nothing
.LANGUAGE         Assembly
.ENDOC            END DOCUMENTATION
; ****************************************************************************
endif

	INCLUDE	\LAT\HEADER\DOS.MAC	; symbols and macros for Lattice

SFRAME	STRUC
	SAV_BX	DW	?
	SAV_ES	DW	?
	REG_BP	DW	?		; base pointer to be pushed
	RTN_ADD	DW	?		; offset of return address
SFRAME	ENDS

	M_LPT1	EQU	08H		; memory location for LPT1 mapping
	M_LPT2	EQU	0AH		; memory location for LPT2 mapping
	SEGMT	EQU	40H		; segment for locations

; ****************************************************************************
; code
; ****************************************************************************
	PSEG				; begin program section

	PUBLIC	LPT_SWAP

LPT_SWAP	PROC	NEAR
	PUSH 	BP
	PUSH	ES
	PUSH	BX
	MOV	BP,SP

	MOV	AX,SEGMT		; load segment register
	MOV	ES,AX

	MOV	AX,WORD PTR ES:[M_LPT1]
	MOV	BX,WORD PTR ES:[M_LPT2]

	MOV	WORD PTR ES:[M_LPT2],AX
	MOV	WORD PTR ES:[M_LPT1],BX

	POP	BX
	POP	ES
	POP	BP
	RET
LPT_SWAP	ENDP

	ENDPS				; end program section

	END				; end assembly

; ****************************************************************************
; Test program
; ****************************************************************************

	PAGE	59,132
	INCLUDE	\LAT\HEADER\CSUB.MAC

CODE 	SEGMENT PUBLIC

ASSUME	CS:CODE, DS:CODE, SS:CODE, ES:CODE
	EXTRN	LPT_SWAP:NEAR

	ORG	100H			; .COM origin

MAIN	PROC	FAR

START:	PUSH	DS
	SUB	AX,AX
	PUSH	AX			; leave return address
	MOV	BP,SP

	DISPLAY	MSG
	CALL	LPT_SWAP
	MOV	SP,BP

	RET				; to DOS
MAIN	ENDP

MSG:	DB	'Swapping LPT1 and LPT2',CR,LF,CPMEOS

CODE	ENDS

	END	START

; ****************************************************************************
; End LPT_SWAP.ASM
; ****************************************************************************


	...!gatech!stiatl!todd
	Todd Merriman 404-377-8638
	Atlanta, GA