Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!snorkelwacker!think!samsung!cg-atla!fredex
From: fredex@cg-atla.UUCP (Fred Smith)
Newsgroups: comp.lang.c
Subject: Re: program out of control
Keywords: lockup, repeats
Message-ID: <8245@cg-atla.UUCP>
Date: 15 Jan 90 01:20:39 GMT
References: <10987@attctc.Dallas.TX.US>
Reply-To: fredex@cg-atla.UUCP (Fred Smith)
Distribution: na
Organization: Agfa Compugraphic Division
Lines: 29

In article <10987@attctc.Dallas.TX.US> bobc@attctc.Dallas.TX.US (Bob Calbridge) writes:
>             Last night when I made some changes to the program that were not
>related to correcting the problem (I decided to get the rest of the program
>working before tackling this problem) the symptoms changed.  Instead of
>locking up, the system started to beep and display the menu continuously.  The
>beep is appropriate if there is an invalid input to getch() which is used to get
>the option for the menu.
>
>Many thanks,
>Bob


Just a hunch:  Whenever I make an apparently innocuous change in a 
program, and some weird behavior in another part of the program suddenly
changes, I instantly suspect that somewhere I am clobbering memory in
some way.

I had an instance of that a while back in my MSDOS version of MORE. In this
case on (very)  rare occasions, apparently at random, some lines would
be drawn on the screen in the BOLD attribute which were not supposed to
be bold. It turned out, after MUCH digging and head scratching that I was
under those same rare circumstances, overwriting a character array by one
byte, thereby clobbering another variable which controlled the display 
attribute.

What you describe sounds very much like that sort of occurrence. Those
things can be sheer hell to locate. I wish you well!

Fred