From:	mert0407 AT sable DOT ox DOT ac DOT uk (George Foot)
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Win95 DPMI/CWSDPMI problems
Date:	14 Jul 1997 22:26:36 GMT
Organization:	Oxford University, England
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Message-ID:	<5qe92s$lbb@news.ox.ac.uk>
References:	<5qe2tj$khu$1 AT news DOT utdallas DOT edu>
NNTP-Posting-Host:	sable.ox.ac.uk
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

David G Farrell (fdavid AT utdallas DOT edu) wrote:
: with no problems. It seems as if the Win95 DPMI server is more lenient
: on errant memory accesses than CWSDPMI. Is this true? Has anyone ever had a
: similar problem? I thought my code was fairly debugged and well-working until
: this. I've tried to get it to crash under Win95 but it won't, ironically. Is 
: there anything that a Win95 DOS box will let you get away with that
: CWSDPMI won't?

I believe Win95's DPMI server allows null-pointer dereferences while
CWSDPMI's doesn't, but I could be wrong. It is probably an errant pointer,
as you guessed.

Have you tried symifying the crash information it gives?  This will tell
you what function caused the error, and if you included debugging
information (pass -g to gcc) it will tell you the source filename and line
number of the error. Look for pointers dereferenced there, and make sure
their values are unquestionably correct, and in particular check they have
been initialised.

-- 
George Foot <mert0407 AT sable DOT ox DOT ac DOT uk>
Merton College, Oxford

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