Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!wuarchive!uunet!omni!bob
From: bob@omni.com (Bob Weissman)
Newsgroups: comp.os.msdos.misc
Subject: Re: "Packed file is corrupt" error and MS-DOS 5.0
Message-ID: <6363@borabora.omni.com>
Date: 25 Jun 91 18:14:11 GMT
References: <1991Jun24.195425.19543@jarvis.csri.toronto.edu>
Organization: Interphase West, Mountain View, CA
Lines: 30

In article <1991Jun24.195425.19543@jarvis.csri.toronto.edu> west@turing.toronto.edu (Tom West) writes:
>  I have been getting "Packed file is corrupt" errors when trying to
>run certain applications after installing MS-DOS 5.0.  Any idea what 
>might cause this?  Specifically qbasic and PC-NFS telnet give this
>error when I try to run them.
>  I assume it has to do with devicehigh, since if I don't load anything
>high, the problem goes away, but I was wondering if anyone else has had
>any experience with this problem.

This problem is documented nicely by Quarterdeck in their QEMM386 manual.

It's a bug in EXEPACK which only appears when the packed .EXE is loaded
below 64K, i.e., into a memory address below 0x1000, and the A20 address
line is enabled.  That's why you're suddenly seeing it -- you have freed
enough low memory to allow programs to load there.

The best solution is to get the LZEXE program from your favorite public
domain archive.  It comes with a program which unpacks EXEPACK-ed files.
If you're short on disk space, you can then re-pack the .EXE with LZEXE
and end up with a *much* smaller file than produced by EXEPACK.

The suboptimal quick'n'dirty solution is to run the program in a sub-shell to
use up more low memory.  I.e., do
	command /c <program> <args>
which has a good chance of using up enough low memory to "fix" the problem.

-- 
Bob Weissman
Internet:	bob@omni.com
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