Can a IBM Thinkpad 600 CPU be upgraded. It has a P 233 in it now. In the Maintenance manual the system board is the same for p-233, p2-233, p2-266, p2-300. It looks like the chipset is on the CPU card so that is why the P1 and P2 can use the same system board. It uses a mmc-1 connector. Can I use any CPU with a MMC-1 conector that hes the same size and shape. I see on ebay for like $20 a P2-400 could this workas long as its a mmc-1. I may have to open the case anyway to replace the fan so I was thinking about the CPU. Now got this for free only spent $18 for some extra memory. It looks brand new it was in a leather case in a sealed plastic box for 2-3 years. I installed Win2000 with no problems. This is not my main laptop but just a project to play with so I don't care to much if I break it.