with an up-to-date BIOS
any Intel Socket CPU (Celeron1/2, P2, P3)
the PPGA Celerons
And any Coppermine CPU (Celeron 2, P3)
You just do not have support for the NEWEST P3/celeron CPU's...
they are often refered to as Coppermine-T's
they also look diffent as the CPU DIE is not showing by covered by a metal plate