You can check like www.ramjet.com which has good info about RAM. I'd guess the memory from one iceBook will fit and work in any other new-style iBook. Also in a Powerbook, although the speed may be different for full performance in a Powerbook. The 512MB I got for my iceBook was crosslisted for both G4 Powerbooks and for iceBooks. I've seen posts which suggest there are minor variations among batteries for different models, but don't know myself. On Tue, 20 May 2003 Shahara9 at aol.com wrote: > I presently have an icebook, two years old, and am eventually going to > purchase either another 12" iBook, or perhaps a Powerbook, and am wondering > if my extra 128 MB DIMM1/J12 SDRAM in this laptop can be used in either of > the newer laptops. Are the batteries similar? I doubt between iBook and > Powerbook, but older and new iBooks ? . . .