From: utzoo!decvax!ucbvax!info-cpm
Newsgroups: fa.info-cpm
Title: MPM 2 bug
Article-I.D.: ucbvax.168
Posted: Wed Dec  1 00:54:47 1982
Received: Thu Dec  2 04:47:09 1982

>From mwm@Okc-Unix  Wed Dec  1 00:34:33 1982
To: info-cpm@Okc-Unix
Cc: mwm@Okc-Unix
Via:  Okc-Unix; 30 Nov 82 23:25-EST
Via:  Brl; 30 Nov 82 23:38-EST
Via:  Brl-Bmd; 30 Nov 82 23:46-EST

About 6 months ago, I ran into a (rather nasty) MPM 2.0 bug. While discussing
DRI's software support with someone, this came up again. Somebody suggested
posting it here, both as a warning, and on the off chance that sombody
knows of a fix.

The problem is that MPM does NOT reinitialize page zero in a when a process
exits, unless page zero of the partition is also page zero for a bank.

This is a problem if you have a program that twists things in page zero. Any
of the `CCP replacements' (microshell, etc) or a menu-driven system that
uses program chainging (Magic Wand II) will trip over this. The sympton is
that, after running such a program, you get the thing back the very next time
something exits, IF you took a hard (^C or whatever) exit.

When I talked to DRI about it, they said `send us a disk with software that
displays the problem, and we may look at it.' Just one of the many reasons
that I hate DRI.

	<mike