XPostFacto... While Apple has limited its support for Mac OS X to those machines that originally came with a G3 or G4 processor, it is possible to install Mac OS X on some earlier machines. The unsupported machines that work now are the 7300, 7500, 7600, 8500, 8600, 9500 and 9600, as well the clones that were based on one of these systems (the Umax S900 and J700, and the Power Computing PowerWave and PowerTower Pro). The original processors in these machines will work (with the exception of the 7500, which requires a processor upgrade). G3 or G4 upgrade cards work as well. Other models that use the PCI architecture may be made to work in time