I know that the RAM limit in the MacBook Pro is 2GB. However, this is most definitely not due to hardware limitations. Technically speaking, the CPU and chipset can address up to 3.3GB RAM. I also know that the computer won't boot with more than 2GB in it. I have reason to believe that this is therefore a firmware limitation. Has anybody done any work modding MacBook firmware? I am considering working on this myself, but if anybody has information about how the firmware flashing process works, that would be quite useful. I also would particularly like to know if Apple firmware updates are signed or if anything can be flash into ROM.