What versions of the Mac OS will work with a G4?
It is highly recommended that Macs running with a MAChSpeed G4 ZIF have Mac OS 9.0.4 or later installed. While it has been announced that Mac OS X will only run on Apple G3s and higher, we are hard at work to provide a solution to allow Mac OS X to run on our upgrades. We are eagerly awaiting Apple’s next developer’s version so we can continue our testing with the goal of providing compatibility.