Maybe Little bit vintage for Reddit but Mac OS 9 on my powerbook G4 12inch ,it boots but the sleep mode function doesn't work and I can't change it anymore than 256
17-inch PowerBook G4 "Aluminum" Memory Installation Video - YouTube
Apple iBook G4 Memory and Ram Upgrade
How to upgrade RAM in your Apple iBook G4 - YouTube
OFFTEK 1GB Replacement Memory RAM Upgrade for Apple iBook G4 A1054 (PC2100) Laptop Memory at Amazon.com