Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!snorkelwacker!ira.uka.de!fauern!fauern!csbrod
From: csbrod@medusa.informatik.uni-erlangen.de (Claus Brod )
Newsgroups: comp.arch
Subject: Re: 486 bugs -- it's in there!
Message-ID: <2813@medusa.informatik.uni-erlangen.de>
Date: 25 May 90 09:59:34 GMT
References: <634@sibyl.eleceng.ua.OZ> <76700202@p.cs.uiuc.edu> <350@necssd.NEC.COM>
Organization: CSD, University of Erlangen, W-Germany
Lines: 22

harrison@necssd.NEC.COM (Mark Harrison) writes:
>> microprocessor revelations, '286, '386 (2, right?), and now I wonder
>> -- will there be a bug in the '486?

>You've already lost.  There was a bug when a trig function followed
>a sequence of integer instructions.  Does anybody still have a copy
>of the article that described this?  Is Intel unique in having bugs
>in their newly released chips?

Motorola's 68000 had a kind of quirk that caused a clr command to
first read the addressed location and then clear it. This led
to numerous difficulties when clearing I/O registers. This one,
however, has always been documented by Motorola, so it's more
a feature than a bug. Subsequent 680x0s perform a clr operation
as God intended.


----------------------------------------------------------------------
Claus Brod, Am Felsenkeller 2,			Things. Take. Time.
D-8772 Marktheidenfeld, West Germany		(Stolen from unknown.)
csbrod@medusa.informatik.uni-erlangen.de
----------------------------------------------------------------------