Category : Assembly Language Source Code
Archive   : DOCFILES.ZIP
Filename : LPTPORT.DOC

Output of file : LPTPORT.DOC contained in archive : DOCFILES.ZIP

LPTPORT John Dickinson
Command PC Magazine Vol 4, No 5
Copyright 1985 Ziff-Davis Publishing Company

Purpose: Permits alternate use of two parallel
printers (e.g., letter- and draft-quality
units) with software that is normally limited
to using LPT1:.


Remarks: Certain software, e.g., the PC-DOS Shift-
PrtSc routine, does not recognize a command
such as


To use such software with two different
printers normally requires changing physical

LPTPORT.COM provides a software toggle that
interchanges the internal DOS I/O addresses
of LPT1: and LPT2:. After entering the
LPTPORT command, a second printer, connected
to LPT2:, will receive program output
nominally directed to LPT1:. Entering the
LPTPORT command a second time restores the
original port assignments.


1. Certain internal print-spooling
programs, such as those supplied with
add-on memory board cards, read the port
address assignments at boot-up time and
do not thereafter look at the low-memory
area of DOS to find them. With such
programs you will have to run LPTPORT
before the print spoolers are loaded in
order to change the effective port

  3 Responses to “Category : Assembly Language Source Code
Archive   : DOCFILES.ZIP
Filename : LPTPORT.DOC

  1. Very nice! Thank you for this wonderful archive. I wonder why I found it only now. Long live the BBS file archives!

  2. This is so awesome! 😀 I’d be cool if you could download an entire archive of this at once, though.

  3. But one thing that puzzles me is the “mtswslnkmcjklsdlsbdmMICROSOFT” string. There is an article about it here. It is definitely worth a read: