Article View: comp.sys.ibm.pc
Article #14847Re: LPT3 support without an installed Mono Display Card - Query
From: John R. Levine
Date: Mon, 15 Dec 1986 01:44
Date: Mon, 15 Dec 1986 01:44
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In article <133@parcvax.Xerox.COM> burton@parcvax.Xerox.COM (Philip M. Burton) writes:
>I would like to configure a second parallel port in my PC AT as LPT3, and use
>the LPT2 interrupt for another purpose. ...
There's no need. DOS doesn't run the printer with interrupts anyway. The
worst that can happen is that occasionally your interrupt routine will get
called because of a printer interrupt rather than because of your device.
Due to the poor design of the IBM printer interface, you can't run the printer
with interrupts -- there's no way to keep from losing the interrupts. Programs
that appear to do so such as the "print" print spooler are actually polling the
printer when the clock interrupts.
--
John R. Levine, Javelin Software Corp., Cambridge MA +1 617 494 1400
{ ihnp4 | decvax | cbosgd | harvard | yale }!ima!johnl, Levine@YALE.EDU
Where is Richard Nixon now that we need him?
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: arc1-ca.pugleaf.net!utzoo!mnetor!seismo!rutgers!mit-eddie!genrad!decvax!ima!johnl From: johnl@ima.UUCP (John R. Levine) Newsgroups: comp.sys.ibm.pc Subject: Re: LPT3 support without an installed Mono Display Card - Query Message-ID: <295@ima.UUCP> Date: Sun, 14-Dec-86 20:44:01 EST Article-I.D.: ima.295 Posted: Sun Dec 14 20:44:01 1986 Date-Received: Tue, 16-Dec-86 22:48:47 EST References: <133@parcvax.Xerox.COM> Reply-To: johnl@ima.UUCP (John R. Levine) Distribution: na Organization: Javelin Software Corporation Lines: 16 Keywords: LPT3, DOS patch Summary: DOS doesn't use interrupts for lpt