Date:	Wed, 18 Sep 2002 21:16:29 +0300
From:	"Eli Zaretskii" <eliz AT is DOT elta DOT co DOT il>
Sender:	halo1 AT zahav DOT net DOT il
To:	Gisle Vanem <giva AT bgnett DOT no>
Message-Id:	<3405-Wed18Sep2002211628+0300-eliz@is.elta.co.il>
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CC:	djgpp AT delorie DOT com
In-reply-to:	<Pine.UW2.3.95.1020914230401.17249A-100000@bryggen.bgnett.no>
	(message from Gisle Vanem on Sat, 14 Sep 2002 23:05:38 +0200 (MET
	DST))
Subject:	Re: Detecting debugger
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> Date: Sat, 14 Sep 2002 23:05:38 +0200 (MET DST)
> From: Gisle Vanem <giva AT bgnett DOT no>
> 
> That worked, thanks. I don't quite see why this should work. Seems the
> real-mode timer-handler isn't called to update the timer-tick unless
> I do call __dpmi_yield().

If this is under plain DOS (no Windows) using CWSDPMI, then what you
see is due to a subtle misfeature in the way CWSDPMI implements the
Int 31h interface.  It's a long story, but the bottom line is that
under some circumstances interrupts become disabled.  Insert an
__asm__("sti") into the loop, and I believe the problem will go away.

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