Path: utzoo!censor!geac!maccs!cs4g6ag
From: cs4g6ag@maccs.dcss.mcmaster.ca (Stephen M. Dunn)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Hard Disk hookup via parallel port...?
Message-ID: <25AD7304.25287@maccs.dcss.mcmaster.ca>
Date: 12 Jan 90 06:02:43 GMT
References: <1676.259f524a@cc.helsinki.fi> <344@marvin.moncam.co.uk> <3932@orion.cf.uci.edu> <349@marvin.moncam.co.uk>
Reply-To: cs4g6ag@maccs.dcss.mcmaster.ca (Stephen M. Dunn)
Organization: McMaster University, Hamilton, Ontario
Lines: 22

In article <349@marvin.moncam.co.uk> emmo@moncam.co.uk (Dave Emmerson) writes:
$To a lesser extent, the same may hold true for parallel ports, here the
$real problem is that the BIOS only expects to use it for output, so I
$guess that with a suitable driver even some older machines might be able
$to use them bidirectionally.

   Well, it's true that the BIOS is set up to expect a printer to be an
output-only device ... but that isn't the problem.  It's very easy to
write a device driver for a parallel port if it's designed to be bi-
directional.  The problem is that most aren't.  Since printers using
the standard Centronics interface are output-only peripherals, those
people who designed printer ports, either for motherboards or for
I/O cards, often don't include bidirectional capabilities in them
for obvious reasons.  That's where the problem lies - depending on
the design of your printer port, you may well blow one or more chips
if you try to use it as a bidirectional port.

-- 
Stephen M. Dunn                               cs4g6ag@maccs.dcss.mcmaster.ca
          <std_disclaimer.h> = "\nI'm only an undergraduate!!!\n";
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    If it's true that love is only a game//Well, then I can play pretend