Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!rochester!pt.cs.cmu.edu!MATHOM.GANDALF.CS.CMU.EDU!lindsay
From: lindsay@MATHOM.GANDALF.CS.CMU.EDU (Donald Lindsay)
Newsgroups: comp.arch
Subject: Re: NMI bug
Message-ID: <10324@pt.cs.cmu.edu>
Date: 25 Aug 90 13:37:30 GMT
References: <1990Aug3.204358.330@portia.Stanford.EDU> <40694@mips.mips.COM> <2399@crdos1.crd.ge.COM> <1990Aug10.171744.9639@zoo.toronto.edu> <14623@drilex.UUCP> <1990Aug20.151438.27121@ecn.purdue.edu> <10307@pt.cs.cmu.edu> <2450@crdos1.crd.ge.COM>
Organization: Carnegie-Mellon University, CS/RI
Lines: 16

In article <2450@crdos1.crd.ge.COM> davidsen@crdos1.crd.ge.com
	 (bill davidsen) writes:
 [referring to a long-ago bug in the 8088 interrupt logic]
>  Was this problem only with NMI? I've run a lot of interrupts into an
>original XT and never seen a problem.

It was only the NMI, and since many boards didn't use NMI, the bug
escaped into the field.  Intel fixed the chip before the XT came out.

The reason I brought this up, was to illustrate a moral:  features
that aren't used, very possibly won't work and never did.

Much like Saltzer's Law: if a system is reliable enough, then the
outage procedures don't work any more.
-- 
Don		D.C.Lindsay