>> I have a Blueberry clamshell ibook. I have a 256mb dimm in the top >> slot, and according to mac, that's all I can install there. If I were >> to say drop in a 512mb dimm, would it recognize the additional memory? I just did that (installed a 512) and now my Blueberry (rev 1 with 32 MB of ram) now indicates 544. I'm not sure - but I do think you need to have the latest and greatest firmware installed. Easily done via software update. Dan