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Path: utzoo!utgpu!water!watmath!dalcs!aucs!paul
From: paul@aucs.UUCP
Newsgroups: comp.sys.ibm.pc
Subject: Interrupt driver for parallel printer
Message-ID: <371@aucs.UUCP>
Date: Thu, 11-Jun-87 08:51:58 EDT
Article-I.D.: aucs.371
Posted: Thu Jun 11 08:51:58 1987
Date-Received: Sat, 13-Jun-87 07:17:15 EDT
Reply-To: paul@aucs.UUCP (Paul Steele)
Distribution: na
Organization: School of Computer Science, Acadia Univ., Nova Scotia
Lines: 25

I am having difficulty in getting an interrupt driven parallel printer
driver to work (the way I think it should).  I've done all the necessary
initialization and changing of interrupt vectors, but when a character is
output (via the output/strobe toggle sequence, no interrupt occurs to
indicate that the printer is ready to accept another character.  The
only time the interrupt routine seems to get called is when I take the
printer off/on line, which is useless for the most part.  I want to
avoid polling the printer as much as possible.

The XT Technical Reference Manual says that an interrupt occurs when
pin 10 (busy) transitions high to low.  As far as my understanding
of a parallel printer adapter, this should happen after every character
is output.  I have written an interrupt driven routine for a QX-10 and
it worked as I would suspect.

I could go into more details, but I leave it as is for now.  If anybody
has any information about using interrupts with the parallel printer
adapter, please drop me a line.  I'll summarize for the net if I get
enough responses.


Paul H. Steele      UUCP:      {seismo|watmath|utai|garfield}!dalcs!aucs!Paul
Acadia University   BITNET:    {Paul|phs}@Acadia
Wolfville, NS       Internet:  {Paul|phs}%Acadia.BITNET@WISCVM.WISC.EDU
CANADA  B0P 1X0     PHONEnet:  (902) 542-2201x587