> Generally speaking, the newer memory designed for the faster bus will > throttle back to the slower speed of the older systems. I.E., PC133 > memory should work in PC100 and PC66 systems, but PC66 memory will not > work in a machine that requires PC100 memory or faster. Yep, now that you mention it... I remember getting a few different speeds as I added sticks to a Celeron box I put together years ago. Part of my buying decisions when adding RAM later were based on potentially moving the memory to a newer machine with a faster bus. Unlike processors with their multipliers, seems most any speed fast will work in something slower if the pins fit, etc. I did check at TransIntl quickly, and they certainly seem to sell the same RAM for each iceBook now. Just wonder what I bought when I added RAM to this iBook. Between keeping my Airport card and RAM (though "free RAM" is all over these days), I'd like to talk myself into the $1000 iBook instead of the $1600 G4, but I'm not doing very well! Thanks for the info. Ruffin Bailey