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From: krowitz%richter@UMIX.CC.UMICH.EDU (David Krowitz)
Newsgroups: comp.sys.apollo
Subject: Re: Need help with BSD4.3 printing through parallel port...
Message-ID: <8912011439.AA03867@richter.mit.edu>
Date: 1 Dec 89 14:39:11 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
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I've written GPIO drivers for the IBM-PC/XT parallel card (which is
hardware compatible with the SPE parallel port) and the Ikon 10092/10097.
I run the XT card using programmed I/O and get roughly 60,000 characters
per second through it to our Shinko color printers (running on a DN3000,
on a DN3500 the rate goes up to roughly 100,000 bytes/sec). It seems
like the SPE driver must be trying to use interrupt driven I/O -- which
is a *very* bad idea with a character-at-a-time device. I will be
looking into doing a streams manager interface for these GPIO drivers
so that the parallel port can be simply referred to a /dev/lpt in
the print-server config file ala Michael Lampi's suggestion.


 -- David Krowitz

krowitz@richter.mit.edu   (18.83.0.109)
krowitz%richter.mit.edu@eddie.mit.edu
krowitz%richter.mit.edu@mitvma.bitnet
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