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From: am42+@andrew.cmu.edu (Alexander Paul Morris)
Newsgroups: comp.lang.pascal
Subject: Re: Displaying EGA/VGA graphics. (Screen Captures)
Message-ID: <obsajcG00aw_EGv29h@andrew.cmu.edu>
Date: 16 Mar 91 19:03:04 GMT
References: <3977@ac.dal.ca> <1991Mar13.041954.26340@ux1.cso.uiuc.edu>,
	<1991Mar13.071250.11258@ux1.cso.uiuc.edu>
Organization: Carnegie Mellon, Pittsburgh, PA
Lines: 14
In-Reply-To: <1991Mar13.071250.11258@ux1.cso.uiuc.edu>

The problem in the code (the BUG, as it is called) is very simple to
correct. The author (I believe Alan Mead) overlooked, since he was using
a linked list, to declare the image as a pointer when he called it with
getimage/putimage.  To correct everything, simply replace in the lines
that say  GetImage  and  PutImage   the parameter   l^.Image   to  
l^.Image^ .  Note that those are the ONLY places where anything must be
changed.  All those weird lines will dissapear.  Actually, I'm surprised
the whole program didn't crash!  Seems like it would overwrite all
memory past the location in mem where that variable is stored, but
perhaps that was just other TP vars or something that weren't important
at the time.  Hope this helps.

    Alexander Morris                  "People die, things change...
    Carnegie Mellon                             It's sad."