Re: Trapping INT 21 is easy.

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#1206

From: DAVID SCOTT PASCHAL
Date: Tue, 01 Sep 1992 21:54

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Hi.  Whenever the 80x86 invokes an interrupt handler, it clears the interrupt
and trap flags after it pushes the old copy onto the stack.  In a non-hardware
interrupt handler it's generally a good idea to re-enable interrupts (with STI)
but always disable them when you chain to the previous handler.  I'm not sure if
this is the problem in your case (sounds really weird!) but it might be
something to check on.

Tschuess,
David Paschal

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Path: arc1-ca.pugleaf.net!sparky!uunet!cs.utexas.edu!zaphod.mps.ohio-state.edu!sdd.hp.com!swrinde!gatech!taco!dspascha
From: dspascha@eos.ncsu.edu (DAVID SCOTT PASCHAL)
Newsgroups: comp.os.msdos.programmer
Subject: Re: Trapping INT 21 is easy.
Message-ID: <1992Sep1.215423.29910@ncsu.edu>
Date: 1 Sep 92 21:54:23 GMT
References: <1992Aug31.230136.2195@brandonu.ca>
Sender: news@ncsu.edu (USENET News System)
Reply-To: dspascha@eos.ncsu.edu (DAVID SCOTT PASCHAL)
Organization: North Carolina State University, Project Eos
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Originator: dspascha@c00089-100lez.eos.ncsu.edu

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