> I see reference to Classic and Thunderbird slot A processors and was
> wondering if they are interchangeable in slot A motherboards or does the
> mobo have to support the Thunderbird technology for the cpu to work?

Dennis,
I presume you mean by Classic, - the trusty old Athlon at it's various speeds?

The answer seems to lie in the chipset version.
The KX133 evolved into the KT133, for Athlon and Duron,  -  the later KT133a
is needed for the Thunderbird.
It mostly has to do with different L2 cache sizes and faster FSB speeds.
A visit to VIA Techs website will show which chipsets are needed for different
CPUs.

The Socket A config. remains the same all the way through.

Personally I'd wait awhile before upgrading, - PC sales have slumped, AMD have
announced a more aggressive approach to marketing and Intel have already
dropped their pricing dramatically in reply.
It will be interesting to see what happens in the lead-up to Xmas.

Kevin

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