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From: david@csource.oz.au (David Nugent)
Newsgroups: comp.sys.intel
Subject: Re: Undoc'd immediate MUL in 80X86 (incl.8086)
Message-ID: <47.25DA5AA9@csource.oz.au>
Date: 15 Feb 90 18:18:08 GMT
Organization: Unique Computing Pty Limited (Vic)
Lines: 24


 > Message-ID: <622@tuura.UUCP>
 >
 > the instructions AAM and AAD revealed a neat way to do
 > immediate 8-bit
 > MUL and DIV on 80X86:s.  The 'feature' is *ABSOLUTELY*
 > undocumented by
 > either Intel or Microsoft or any other organization associated. Who-
 > ever uses it must consider the possibility of the instructions not
 
 
This is actually documented and implemented in Eric Issacson's shareware 
80x86 assembler "A86".  A nice feature really, and it's a pity it 
didn't get documented.  This won't work with certain brands of NEC 
microprocessors though, such as the V20 and V30.
 
 
david


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