Message-Id: <199803270351.WAA01451@renoir.op.net>
Comments: Authenticated sender is <edgee@cyberpass.net>
From: "Ed G." <edgee@cyberpass.net>
To: pups@minnie.cs.adfa.oz.au
Date: Thu, 26 Mar 1998 22:51:31 -0400
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Subject: Bug in Bob Supnik's Emulator!
Reply-to: edgee@cyberpass.net
Sender: owner-pups@minnie.cs.adfa.oz.au
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As you know, I wrote this list recently about a bug in Bob Supnik's 
emulator which manifests when running factor (1).  

I've had a chance to do some further research on this, and it seems 
to me that the bug is definitely in Supnik's emulator.  What do you 
all think?  Am I onto something?  If so, what part of Supnik's code 
is probably to blame?

Here's what I've learned so far:

1. factor on Supnik's emulator fails most of the time (see below for 
examples).

2. factor works fine on Ersatz-11

2. On the off-chance that I munged the disk images and somehow
corrupted factor, I reextracted virgin images from the tar ball. 
factor still fails while running on Supnik's emulator.

3. Peter Turnbull wrote me that factor running on under uv7 on his 
PDP-11/23 runs the test case 'factor 6' without error.

Here's what factor does on Supnik's emulator for a variety of values:

factor 6
2
3
17
17 etc.

factor 257
263
263 etc.

factor 263
269
269 etc.

factor 1009 (works correctly)
1009