|"I would like to know what AMD processors work with PC800"|
None. AMD systems don't use RDRAM (aka RAMBUS)...it was strictly an Intel thing (that flopped, BTW).
But to answer your question, the motherboard determines the type of RAM (SDR, DDR, DDR2, etc) & the supported speeds (200MHz, 333MHz, 400MHz, 533MHz, etc). Once that info is known, the RAM is selected with the type/speed/FSB of the CPU in mind.