The PowerBook G4 17" can be upgraded to 2GB by adding a 1GB memory module to the open socket and replacing the 512MB memory module in the remaining socket with a 1GB memory module.

Standard Memory
512MB Removable
Maximum Memory
1GB or 2GB
Memory Expansion (No. of sockets)
1 or 2 Expansion Sockets
Memory Expansion
Install 1 at a time
Memory Sizes
256MB | 512MB | 1GB
Memory Speed (Type)
PC2700 or PC2100

Note that the different models of units use either PC2100 or PC2700 ram. Click on the individual chips to see compatible models.