10 Dec
2005
10 Dec
'05
12:44 a.m.
Chuck Guzis wrote:
The V20 and V30 had an emulation bug that would cause
nasty things to
Speaking of 808x CPU bugs, I remember a bit of controversy over altering the
stack registers. You were supposed to be able to do this:
MOV SS,AX
MOV SS,DX
...to switch the stack to somewhere else, and the 8088 was supposed to disable
interrupts after the MOV SS for the next instruction (MOV SP). However, I read
somewhere that early versions of the 8088 didn't honor this (or at least didn't
honor it all the time). The generally accepted workaround was something like:
CLI
MOV SS,AX
MOV SS,DX
STI
What I'd like to know is: What revisions of the 8088 were susceptible to this?
Here's another dumb question: When I open up one of my XTs, why does my 8088-1
have an AMD logo on it?
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
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