Will the T7700 CPU work in a T61 without any major upgrades? Also, what is the maximum RAM alllowed in T61?
The T7700 (2.4GHZ) CPU is a Merom processor and is compatible with any T61 or T61p. If you encounter a blank screen upon installing the T7700 CPU, then you may need to update your BIOS.
However, in general, do not update your BIOS unless absolutely necessary as a failed BIOS update can brick your computer.
As for maximum memory, T61 can definitely take 2x 4GB= 8GB total DDR2 RAM. If you install a 32-bit operating system you will be limited to a little over 3GB. You will need a 64-bit operating system to access the full 8GB.