Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!usc!jarthur!uunet!sobeco!ygrignon
From: ygrignon@sobeco.com (y.grignon)
Newsgroups: comp.sys.ibm.pc.misc
Subject: Re: Reading PRN:-port
Message-ID: <1990Nov16.135623.4044@sobeco.com>
Date: 16 Nov 90 13:56:23 GMT
References: <1393@tnosoes.izf.tno.nl> <1150@cameron.egr.duke.edu>
Organization: Sobeco Group - Montreal, Canada
Lines: 14

>From article <1393@tnosoes.izf.tno.nl>, by joep@tnosoes.izf.tno.nl (Joep Mathijssen):
> Looking for a program that lets me READ the parallel-port (PRN:) on a
>                                     ^^^^
>If you look in the schematics for any parallel you will find it is a one way
>set of registers.  the only line that comes in is some sort of acknowledge
>line.

FYI on PS2's the parallel port can be made an input port by playing with
the bits at memory location 0x35 (if my memory serves me right).  On older
PC's where the parallel port is made of separate IC's, it is possible to
convert an output only port to input/output by rerouting only one trace.
Such a modification appeared in Circuit Cellar Ink (approx 1 yr ago).

Yves