Okay, so... I currently have 512 MB RAM in my trusty 1GHz 17" iMac G4, but I want 1GB. Here's the thing I'm not sure about. I know that from Apple, this computer was to have 256 MB RAM. When we purchased it, it was a special order that had 512 MB. I understand that there are two slots, an upper and a lower slot. My question is, if I have 512 now, where is that located? All in the upper slot, or 256 in the upper, and 256 in the lower? If there's 256 in the lower, replacing it with a 512 will still give me more (768) but not 1056 MB which is what I want. Weah... That's confusing. Attached is a screenshot from System Profiler that might help you understand.