Path: utzoo!mnetor!uunet!seismo!sundc!pitstop!texsun!texsun.central-relay.sun.com!convex!convexe!authorplaceholder
From: loafman@convexe.UUCP
Newsgroups: comp.sys.ibm.pc
Subject: Re: help with device driver
Message-ID: <63200032@convexe>
Date: 17 Feb 88 16:43:00 GMT
References: <5464@cit-vax.Caltech.Edu>
Lines: 25
Nf-ID: #R:cit-vax.Caltech.Edu:-546400:convexe:63200032:000:1167
Nf-From: convexe.UUCP!loafman    Feb 17 10:43:00 1988


>I have the basic driver up and running.  My problem is
>that the device I am talking to sometimes takes a very
>long time to complete its task.  Other times it is
>simply stuck.  So, I would like the user to be able to
>hit ^Break to stop the driver (and the program that
>did the i/o).
>
>How does a device driver that is spin waiting for a
>device determine if ^Break has been hit?
>
>One possibility is to chain off the 0x1b interrupt
>vector.  Isn't there a more civilized way?

Not really.  DOS never intended for a device driver to be interrupted
by a control break.  The 0x1B interrupt is probably the best solution.
Just set a flag there and poll on that one as you wait for you device
to complete or stick whichever the case may be.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Kenneth W. Loafman @ CONVEX Computer Corp, Dallas, Texas | All opinions
Voice:	  work: (214) 952-0829  home: (214) 964-1250     | are my own,
USPSnail: 1705 Coit Rd #2101, Plano, Tx 75075		 | of course.
UUCP:	  ihnp4!convex!loafman	|  CompuServe: 72345,233 |        ...KWL
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