I decided to scrap my Rev. A iMac and go for a iBook (Firewire) but the thing is when I get the iBook I want to upgrade three things the hard drive, memory, and OS. I looked on Everymac.com and it said "Apple officially reports that the maximum memory capacity of this system is 320 MB with 64 MB of onboard memory. However, third-parties have been able to upgrade the RAM to 576 MB with a single 512 MB memory module." So I'm asking how many Ram slots are there from what I understand Is there two ?