Path: utzoo!utgpu!water!watmath!clyde!bellcore!rutgers!ucsd!ucsdhub!esosun!seismo!uunet!uport!keith
From: keith@uport.UUCP (Keith Hankin)
Newsgroups: comp.unix.microport
Subject: Re: HELP! Floating Point Problems
Summary: Problems with floating point and 80387
Message-ID: <371@uport.UUCP>
Date: 23 Jul 88 04:29:06 GMT
References: <2424@inco.UUCP>
Reply-To: keith@uport.UUCP (Keith Hankin)
Organization: Microport Systems, Scotts Valley, CA
Lines: 22

Your floating point hangs with Microport System V/386 2.2 could be the
result of several things.

1.  The ALR machine may need special code to recognize the presence of
	the 80387 chip.  The Compaq 20MHz machines need this code.  It
	will be included with the next Microport release 3.0 (due out in
	September).
2.  There is a known problem (Called Errata #21 by Intel) with the 80386
	chip.  If you are running in 386 protected mode (which UNIX always
	is) and you have a 80387 chip installed, if there is DMA going
	on (floppy, tape drive or smart serial card access), there is a
	possibility of random system hangs.  This can be fixed by a
	piece of hardware made by Bell Technologies, which by the way,
	will not work with Compaq machines.
3.  There are some bugs in old 80387 chips which would cause processes
	to hang.  A simple awk script is available to test this problem.
	If you can break out of hanging processes by DEL, then it could
	be this problem.  If it is a system-wide hang, then it is not
	this problem.

Keith Hankin	keith@uport
Microport Systems