I have a PowerPC G4 466 Mhz which has three "PC133" thingies in it, one 128 MB and two 256 MB, totalling 640 MB. I want to change those to one, two or three 512 MB cards instead, but the manual says something about there being certain restrictions for 512 cards. Translated from Swedish:"If you install DIMM-modules of 512 MB they must have 256 Mb-units". What does that mean exactly and how do I check that they in fact have "256 Mb-units"? EDIT: Sorry, I just realised that perhaps this should have gone into the "Mac Basics and Help" forum instead.