The best way to overclock your Athlon and Duron CPU is through changing the CPU clock multiplier, not the FSB. The “Pencil Trick” involves reconnecting the L1 bridges on the processor to unlock its full potential, a safe and easy process using a mechanical pencil. Overclocking an Intel CPU involves tweaking the FSB on the motherboard. The room for error is minimal, making it a risk-free task even for those unskilled in mechanics. With some BIOS adjustments and a pencil, you can overclock your CPU significantly. This method is simple, cost-effective, and highly effective. Give it a try and unlock your CPU’s full potential.
http://computer-communication.blogspot.com/2007/06/unlocking-duron-and-athlon-using-pencil_08.html