The PowerBook G4 (Aluminium) 12" can be upgraded to 1.25GB by removing the factory installed 512MB modules and installing a 1GB module.

Standard Memory
256MB Non-Removable
Maximum Memory
Memory Expansion (No. of sockets)
1 Expansion Socket
Memory Expansion
Install 1 at a time
Memory Sizes
256MB | 512MB | GB
Memory Speed (Type)
PC2100 or PC2700

Note: The 1.33GHZ and 1.5 GHZ 12" Models use PC2700 RAM. All other models use PC2100 RAM.