NotebookReview has a guide to pin-modding your old Dothan Pentium-M based notebook. In geekspeak, this amounts to
grounding the BSEL[0] pin, thus “tricking” the CPU Front Side Bus to run at 133MHz instead of 100MHz, since its multiplier stays the same it will overclock by 33% turning a 1.6Ghz CPU (16 X 100Mhz) into a 2.13Ghz CPU (16 X 133Mhz).
Not for the faint of heart!