If the mobo manufacturer has a BIOS update that allows you to configure <lower> the voltage for a Coppermine flash it and buy a FCPGA slotket and P3 or Celeron II, I'm running a Celeron II 600@933mhz in my old Abit BH-6 mobo w/o any problems. < until next week when my AMD T-Bird arrives>
If I were you I would chuck the old stuff and buy a T-Bird 1GHZ, some DDR RAM and new mobo.
The T-Bird 1GHZ will o/c easily to 1.3GHZ from what I've seen in
www.overclockers.com CPU database and total price for hardware is about what you will pay for a mid to high end P3 and slotket.
1GHZ TBird, 256 mb of DDR and a ECS mobo with SiS 735 chipset is only $175.00 including shipping, a P3 1GHZ cpu and slotket will cost around $165-175.00 and won't perform as well as the AMD.