[Mr. Hubert]

I just purchased some used RAM on eBay (1gb) that was listed for the 12" G4 Powerbook G4/Aluminum. I was under the impression that the RAM modules were interchangeable between the different Powerbook sizes. I have a 15" 1.25 ghz aluminum Powerbook. The seller is telling me that it will not fit my application and that he will refund me my money (he hasn't shipped it yet). Is he correct that it is not compatible with the 15" model? Are the RAM modules only "backward compatible," i.e. a PC2700 RAM will fit in a PC2100 slot, but not the other way around?

[Cold Warrior]

I'd go to Crucial and use their RAM finder to see what RAM goes with what product.

Memory upgrades, graphics cards, flash media, and usb storage at Crucial.com

[mduell]

The aluminum PowerBooks use at least 3 different types of RAM, so you can't say the memory from an Al PB will work in any other Al PB. Look up the models on apple-history.com to see if they use the same memory.

Yes, PC2700 will work in a machine that needs PC2100, but PC2-4200 or PC2100 won't work in a machine that needs PC2700.