Newsgroups: bit.listserv.wpcorp-l
Subject: Re: Word Perfect 5.1 Problem
From: cctr132@csc.canterbury.ac.nz (Nick FitzGerald, CSC, Uni. of Canterbury, NZ)
Date: 19 Aug 92 10:01:03 +1200
Organization: University of Canterbury, Christchurch, New Zealand

In article <16847C7CC.CARLSON@tamvm1.tamu.edu>, CARLSON@tamvm1.tamu.edu
writes:
> In article <PEPRBV.920817.182430.C0@CFAAMP.BITNET>
> Bob Babcock <PEPRBV@CFAAMP.BITNET> writes:
>  
>>>Inspection of the document using reveal codes shows a number of
>>>unrecognized 'control codes' but we can't remove them.
>>
>>Try WPMD2.ZIP in the MSDOS.WORDPERF directory at Simtel20.  This program
>>is supposed to fix damaged WP documents.
>  
> I'm glad to here about WPDM2.ZIP.  If that doesn't work, I've had success
> using Norton's disk editing program to locate and blank out the offending
> section of the document.  You must identify exactly where the problem
> begins in the document and then locate that place with a program that
> edits binary files.  Replace the corrupted section with blanks and then
> retrieve back into WordPerfect and replace the missing information.

This is poor advice, based on my experience of fixing over three dozen
such corrupted files.  It is very difficult to identify where the
problem "really" starts.  I've seen [Unknown] codes pop up about half
way through a doc when the actual corruption was very near the
beginning.  The [Unknown] codes turned out to be -perfectly valid-
formatting codes (things like footnotes), but because of the real
problem WP was "thrown", and misinterpreted the codes as other than what
they really were.  Also, unless you have a lot of experience with the
internals of WP document files, it is very difficult to pick what is
"valid gibberish" (aka WP formatting code) and what is "invalid
gibberish" (aka corruption).  Taking to the file with a binary editor is
a last ditch thing for desperate situations, and whilst maybe worth
trying, as described above, shouldn't be relied on.  WPMD2 is probably a
much better bet for a first try (running twice or even three times can
sometimes be better than just running it once).

> Usually the corrupt section ends at a track or sector boundary.  Of
> course, always try this on a backup copy of the document so that you
> don't make things worse.

Hmmm - given this, I can see why you profferred the advice above. 
Again, I must say that this doesn't tie with my experience at all.  In
the files I've seen, the corruption doesn't correlate with sector
boundaries - it is almost inevitably in the "middle" of a formatting
code - either a single byte that should be in a multi-byte code is not
written, or is written incorrectly or a sequence which isn't a valid
code is written and WP on subsequent loading of the file, is "upset" by
these.  If it was -generally- of the nature you suggest, then -mostly-
it would be manifested as corrupted text.  (The few exceptions to my
comments above, are when info in the document header, some of which is
quite critical to WP's interpretation of the document, gets corrupted.)

Hope this helps,

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 Nick FitzGerald, PC Applications Consultant, CSC, Uni of Canterbury, N.Z.
 n.fitzgerald@csc.canterbury.ac.nz  (64)(3)  364-2337 Voice,  364-2332 FAX
Comments: Gated by NETNEWS@AUVM.AMERICAN.EDU