Date: Tue, 12 Jan 1999 10:53:36 +0200 (IST)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
X-Sender: eliz AT is
To: Mapson <mapson AT mapson DOT com>
cc: djgpp AT delorie DOT com
Subject: Re: trouble w/code for old DJGPP program
In-Reply-To: <369a40b4.14172714@news.cis.yale.edu>
Message-ID: <Pine.SUN.3.91.990112105314.15876H@is>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Reply-To: djgpp AT delorie DOT com


On Mon, 11 Jan 1999, Mapson wrote:

> My only problem now is that the program crashes instantly upon
> running it. I suppose I will have to go through it by hand and do a
> real update of it.
> 
> It was written with DJGPP 1.09

One thing to look for is the direct writes to some absolute address
like 0xe0000 or some such.  DJGPP v1.x remapped video memory to a
certain absolute address, and graphics programs tended to use that for
speed.  Such a mapping isn't possible in DPMI mode, so v2.x doesn't
provide it.

Or just run symify on the crash traceback and take it from there.
Section 12.2 of the FAQ should get you started with debugging this.