The PowerBook G4 (Aluminum) takes a standard 2.5-inch PATA drive

If you’ve got an Aluminum PowerBook G4 and need more storage, you’re in luck. The drive bay uses a standard 2.5-inch Parallel ATA drive with a ZIF connector — so you can swap in a PATA SSD for a meaningful speed boost, or just drop in a bigger mechanical drive. It’s one of the few genuinely upgradeable spots on a vintage Mac.