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From: jsdy@hadron.UUCP (Joseph S. D. Yao)
Newsgroups: net.micro.pc
Subject: Re: To those who write background resident code.....
Message-ID: <191@hadron.UUCP>
Date: Fri, 17-Jan-86 14:18:20 EST
Article-I.D.: hadron.191
Posted: Fri Jan 17 14:18:20 1986
Date-Received: Mon, 20-Jan-86 05:29:31 EST
References: <2106@phri.UUCP>
Reply-To: jsdy@hadron.UUCP (Joseph S. D. Yao)
Distribution: net
Organization: Hadron, Inc., Fairfax, VA
Lines: 21
Summary: mov ss,x should stop interrupts ...

In article <2106@phri.UUCP> greenber@phri.UUCP (Ross Greenberg) writes:
>FLAME ON......
>	Of course, getting an interrupt when you are between the 
>	mov ss, my_stack_segment  and mov sp, top_o_my_stack instructions
>	can have interesting results.  ...
>FLAME OFF.

This must have been one of the original 8086's.  I didn't read it
here originally (I can't find my original source), but in Stephen
P. Morse's _The_8086_8088_Primer_ (Hayden 1982, AKA "the red book"),
pp 89-90, subtitle \fB An 8086 Mistake \fP:
	[ describes the above problem ]
	This mistake was not discovered until after the 8086
	was designed and built.  After the mistake was dis-
	covered, the 8086 was modified so that it will not
	accept any interrupts immediately after executing an
	instruction that moves a new value into SS.
Says nothing about whether old chips were recalled, or what ...
-- 

	Joe Yao		hadron!jsdy@seismo.{CSS.GOV,ARPA,UUCP}