*** Craig Hart wrote in a message to Peter Magnusson:
 > I'm working on a program that will detect various (newer)
 > processors using CPUID. I currently only have added Intel
 > and AMD support, and I'll try to add Cyrix support later,
 > but according to a description of CPUID I found on
 > the Internet says Cyrix is hard or impossible to identify
 > correctly using CPUID.
CH> The Cx486 SLC/DLC/s/s2/sx/dx/dx2/dx4/5x86 don't support
CH> CPUID. The 6x86 has CPUID turned off by default.
CH> The 6x86MX & MediaGX have CPUID turned on by default.
You sure the 5x86 doesn't support CPUID?
I haven't had an opportunity to check the 6x86MX and MediaGX yet, but if it 
is on by default, then GOOD; they finally turned their brains on... ;)
CH> Furthermore, attempting to enable CPUID in a 6x86 requires
CH> writing to ports 22h and 23h - which many older motherboard
CH> chipsets use as their setup/config ports; writing to them
CH> usually crashes the computer! (ie most/many 286, 386 and
CH> early 486 chipsets, including G2, C&T NEAT, & anything with
CH> an 82c206). 
One can get around this partially by both checking the flags to see if 
they're handled in a Cyrix manner, and then checking that the CPU is a 
Pentium-class or better.
Do you know if ports 22h and 23h are always used the same way in all of the 
chipsets, i.e., write index to 22h and read value from 23h?
CH> If you have internet acvcess, visit www.sandpile.org for
CH> what I consider to be the 'best' set of CPU related
CH> technical documents. He has a great page on CPUID. 
OPCODES.LST in Ralf Brown's Interrupt List (INTER*.ZIP) is also very 
informative.
--Scott.
--- timEd 1.01
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