I have a 17inch 1GHZ G4 iMac and I am trying to figure out if I can/should put more memory in it. I have 768 megs of ram now, and i would like to have the full 1gig of ram. Obviously I have a 512 and a 256 in now, but I want to figure out which size is in the user accessible slot on the bottom of the computer. If it is the 512 thats in there then I can't really upgrade with out messing with the fatory one which i wont do. I know i could just take the bottom off and look, but I'm at school now and don't really feel like doing that until i get home for thanksgiving. I looked in the systemprofiler, and it shows the two memory sticks in my computer, 512MB in slot DIMM0/J22 and 256MB in slot DIMM1/J20. I was just wondering if anyone could tell me from those slot numbers which on is the upgradbale one.