>Unless it's a 500 MHz model, they use PC-66 RAM. Although they *can* use >PC-100, too, so you might be lucky and be able to recycle the RAM in a >PC-100 (600, 700, 800 or 900 MHz models). So, would it be uncommon to find PC-133 RAM in a 800MHz? Factory installed? And would that piece not be compatible in a 600MHz? Just trying to find out if that is what may be causing the problem with my iBook? It's back in for the 3rd time now.... Fran -- Kindness is more important than wisdom, and the recognition of this is the beginning of wisdom. --Theodore Isaac Rubin