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Date: Sat, 07 Feb 2004 16:20:10 +0200
From: "Eli Zaretskii" <eliz AT elta DOT co DOT il>
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To: djgpp AT delorie DOT com
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	(RadSurfer AT yahoo DOT com)
Subject: Re: Achieving 486-Compatibility (2)
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> From: RadSurfer AT yahoo DOT com (Radical NetSurfer)
> Newsgroups: comp.os.msdos.djgpp
> Date: 6 Feb 2004 16:27:18 -0800
> 
> Exiting due to signal SIGSEGV
> Page fault at eip=00014def, error=0004
> 
> What is that error = 0004 ?????????

For Page Fault, the error code of 4 means that your program attempted
to read from a bad address.  (This is explained in section 12.2 of the
FAQ, btw.)

It would be a good idea to post a complete crash traceback, complete
with the full register dump.  Running SYMIFY (or, better yet,
bfdsymify) on it would be even better.  Given that information,
perhaps someone around here could get some useful ideas about possible
causes for the crash.

> the exact same identical program does seem to run
> properly on my P4 with no problems at all....
> 
> Any ideas?

It's a bug.  Page Faults cannot be caused by a bad opcode (which would
be the case if the program couldn't run on a 486): those trigger
SIGILL, not SIGSEGV.  I suspect that the reason for the different
behavior is something else, like memory amount/configuration, for
example.  Windows is quite lenient towards bad pointers.

As DJ suggested: debugging the program is the way to find out what
went wrong.