Newsgroups: comp.sys.3b1
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!batcomputer!cornell!uw-beaver!fluke!vince
From: vince@tc.fluke.COM (Craig Johnson)
Subject: Re: 19.2K on a 3b1
Message-ID: <1991Mar28.215833.1372@tc.fluke.COM>
Summary: Spurious interrupts?
Organization: John Fluke Mfg. Co., Inc., Everett, WA
References: <2214@public.BTR.COM> <35907@ditka.Chicago.COM> <2225@public.BTR.COM>
Distribution: usa
Date: Thu, 28 Mar 91 21:58:33 GMT

Thad, your description of serial port problems makes me suspicious that
you are suffering from spurious interrupts from an anonymous source.
Its been a long time since I've looked into it, but I believe I once
traced a problem like this to a suspicious connection on the parallel
line printer port.  Make sure anything connected there is powered on
and that the connection is solid.  If the printer drives the handshake
lines with open-collector drivers, you may need to see if there is a
problem with missing or bad pullup resistors.

I hope this isn't a wild hair.  It's been a long time since I last looked
into it.

Possibly related?  Has anyone ever figured out the reason UA occasionally
switches windows on you without you asking for it?  Spurious keyboard
noise?  Is it dependent on SW version (I'm only sure I've seen it on a
3.0 machine)?

---
	Craig V. Johnson			...!fluke!vince
	John Fluke Mfg. Co.				or
	Everett, WA				vince@tc.fluke.com