From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
To: Hans-Bernhard Broeker <broeker AT physik DOT rwth-aachen DOT de>
Cc: djgpp AT delorie DOT com
In-reply-to: <8pl5mj$4bj$1@nets3.rz.RWTH-Aachen.DE> (message from
	Hans-Bernhard Broeker on 12 Sep 2000 11:57:07 GMT)
Subject: Re: djgpp query
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Date: Sat, 23 Sep 2000 18:29:32 -0400 (EDT)
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> From: Hans-Bernhard Broeker <broeker AT physik DOT rwth-aachen DOT de>
> Newsgroups: comp.os.msdos.djgpp
> Date: 12 Sep 2000 11:57:07 GMT
> 
> I strongly doubt you can ever hook 0x31 in a DJGPP program. You'ld
> almost invariably end up with an endless loop, because you sawed away
> the branch the whole DJGPP runtime environment is sitting on.

Actually, the DJGPP debug support routines do just that.  But you are
right: it is anything but trivial.  For the gory details, look at the
files in src/debug/common directory inside djlsr203.zip.