Upgrading your Pentium II to a Pentium III
Thinkpads dating from around 1999-2000 have MMC2 CPU daughter boards, and so can be upgraded.
The good news is that the memory bus speed goes from 66MHz to 100MHz.
The catch is that the BIOS produces errors of type 127 when booting (press ESC, then F1). This is solved by modifying one byte in the BIOS, using the integrated BIOS editor (this post).
Be careful when choosing the speed of the new MMC2 daughter board, since there may be problems with voltages/speedstep. 500MHz is a safe choice. Processors with SpeedStep seem to work too but stay at their lowest speed unless one uses physically modifies the daughter board (see the post above).
- ThinkPad 770Z