Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!crdgw1!uunet!comp.vuw.ac.nz!canterbury!cctr132
From: cctr132@csc.canterbury.ac.nz (Nick FitzGerald, CSC, Uni. of Canterbury, NZ)
Newsgroups: comp.binaries.ibm.pc.d
Subject: Re: Failed overlays and FAT errors (omega)
Message-ID: <1991Mar29.122359.356@csc.canterbury.ac.nz>
Date: 29 Mar 91 00:23:59 GMT
References: <101389@tut.cis.ohio-state.edu>
Organization: University of Canterbury, Christchurch, New Zealand
Lines: 37

In article <101389@tut.cis.ohio-state.edu>, simpson@skink.cis.ohio-state.edu
(john simpson) writes:
> 
>     version of Omega (v. 0.71 (beta)) that I had just ftp'd and 
>     found myself dumped back to DOS with an "overlay not found" error.
>     Oh well, I thought, the doc warned of bugs so I'll start over, 
>     right?  Wrong.  Every time I tried to run a program (omega, chkdsk
>     and nu in that order) on my hard drive I got errors about damaged 
>     FATs and corrupt EXE files.  With a sinking feeling in my stomach
>     (how many times had I warned others to make backups?) I ran chkdsk
>     from A: -- no errors!  C: and D: checked out fine (partitions on
>     a 40 meg drive).  I warm booted and everything was back to normal.
> 
>         Has anyone else seen this?  Is it connected with omega or is it
>     "common" after failed overlays?  I ran virus checks before and after
>     (scan67) and my system's clean.  I'm running DOS 3.3 and had cmdedt
>     and print resident.

Haven't seen this with this prog (don't have it) but have seen similar
problems occasionally.  My _guess_ is that Omega is writing "out of bounds"
and corrupting either the system's partial copy of FAT#1 that is kept in RAM
or (if you have it or similar running) corrupting FASTOPEN's table of file
entries.

If so, CHKDSK, NU, and OMEGA must be represented in the same in-memory area
of the FAT and thus the FAT doesn't have to be re-read to load and run them,
and because it's corrupted problems arise.  Did you try going back to C: or
D: after running CHKDSK from floppy - this would have (probably) forced a
re-read of the FAT from disk and all would have been well again.

If you supply more details on where in the game things went wrong, someone
with the game and BoundsChecker might be able to check it out (or the author
might be reading and be able to work on a bug-fix).

---------------------------------------------------------------------------
 Nick FitzGerald, PC Applications Consultant, CSC, Uni of Canterbury, N.Z. 
 Internet: n.fitzgerald@csc.canterbury.ac.nz        Phone: (64)(3) 642-337