There seems to be some confusion about the original iBooks and 512 RAM chips, ever since the writer two weeks ago stated that he bought a 512 stick for his original iBook. Based on his statement (sorry, I forgot his name), I went to OWC.com (Other World Computing) which has a lifetime guarantee for all RAM and which has good checksheets for determining whether any particular size RAM will fit a particular computer. I purchased 512 RAM chips for two of the earliest iBooks: the original 300MHz blueberry (upgraded to 20GB) and the next-to-original 366 MHz gray (purchased used, later upgraded to 30GB). Neither has firewire; they are indeed the original iBooks. The 512 RAM chips fit perfectly, and I do notice a difference in many areas now that I am running the iBooks with so much extra RAM. I use OSX 10.2.5 and OS 9.2.2 on both iBooks. I consider the early clamshell iBooks to be collector's items now and would not think of getting rid of either one of them. I strongly recommend the 512 RAM upgrade for these little computers. If you don't believe it will fit, then buy from a company that guarantees a refund. OWC is not the only company that sells and guarantees 512 RAM chips for the iBooks.