Officially according to Asus, only rev. 1.12 and later and some rev. 1.10 support the Coppermine CPU. That's due to the Vcore regulator in the older P2B which only goes down to 1.8 volts while the Coppermines need 1.6 volts. If you just plug a Coppermine Slot 1 PIII in the older rev. P2B motherboard, it will not boot and you're running the risk of damaging the CPU.