Chop off end of Run ?

[bob1 <bob1@sns-access.com>]

My auto-stop may be ajusted wrong, I've gotten a couple *.gcd files with time
over 140 seconds, even though the run was 40 to 60 seconds.  

Is there a way to chop off or truncate the *.gcd file ?  If I estimate half of
the data is gabage, and use an editor to chop off the last half it doesn't work
for me. I always get into a mode where the windows remain blank and I get dialog
error boxes starting with: "Floating point division by zero".

Robert Larson
Portland,OR