Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!uunet!ingr!b11!jmack
From: jmack@b11.ingr.com (Cery McCormick)
Newsgroups: comp.sys.atari.st
Subject: Re: The 'PHANTOM TYPIST'
Summary: could be...
Message-ID: <7448@b11.ingr.com>
Date: 14 Feb 90 14:44:21 GMT
References: <900204.10484196.021631@SFA.CP6> <17814@laurel.athertn.Atherton.COM> <3832@harrier.ukc.ac.uk>
Organization: Intergraph Corp. Huntsville, AL
Lines: 15

In article <3832@harrier.ukc.ac.uk>, jbww@ukc.ac.uk (J.B.W.Webber) writes:
> In article <13352@watcgl.waterloo.edu> wsflinn@watcgl.waterloo.edu (Scott Flinn) writes:
> >
> >Has anybody else noticed any correlation between rapid sequences of
> >keystrokes (involving multiple backspaces) and the appearance of the Phantom?

	On the Atari, when you hit a key, the keyboard uP sends a 'make'
code via interrupt to the 68000. When you let off of a key, a 'break' code
is sent. If for some reason (fast typing?) the 'break' code for a key
never gets sent, the 68000 will think that the key is still being pressed
down. 
	I ran into this problem when trying to disable all interrupts for
a long period of time. The 'break' code got lost and so the keys just kept
coming until you pressed another one. 
	Is this a resonable explanation??