I have a eMac G4 700 and in the about box there is the system configuration information. I have 512 Gb of RAM, two sticks of 256 Mb. But under the memory information I see them both DIMM0/J1600 SDRAM 256 MB. But there is also a UNUSED empty space and I want to know what it is... Why does OS X thinks there is a UNUSED slot? Cause I only saw 2 slots when I installed my RAMs. Could certainl use another one thoug!