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From: jal@acc (John Lauro)
Newsgroups: comp.os.msdos.programmer
Subject: Re: Detecting an 80486
Message-ID: <1990Aug27.222630.26146@caen.engin.umich.edu>
Date: 27 Aug 90 22:26:30 GMT
References: <OTTO.90Aug15022916@tukki.j <9008211347.AA05979@esegue.segue.boston.ma.us> <4562NU013809@NDSUVM1>
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Organization: University of Michigan - Flint
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In article <4562NU013809@NDSUVM1> NU013809@NDSUVM1.BITNET (Greg Wettstein) writes:
>It is too bad that the original 8086(8) designers did not have omnipotent
>foresight and forsee how well CMOS would scale into the future.  If they
>would the following instruction would have been set in microcode:
>
>                       LMTW  AX
>
>For those of us not omnipotent this translates to Load Machine Type Word.
>Where AX receives: (0 = 8086, 1 = 8088, 2 = 80186, 3 = 80286, 4 = 80386)

Better yet, AH as cpu, and AL as version of CPU.

>
>The only concern then is what happens when the number of processors
>released exceeds the range of an unsigned 16 bit integer. ;-)
>

The 386 and I assume 486 do something like that, but only at power up.
Check your manuals on conditions after reset.  Too bad all 386/486
BIOS makers don't stuff that information somewhere....  An instruction
like LMTW would be much better.

    - John Lauro
      University of Michigan - Flint