plugged keyboard directly into G4 and tried booting from OSX10.3 install disc.It started to load, I got the Apple icon w/spinning wheel under it, it kept spinning + spinning, + spinning with nothing happening so I hit power button. Tried again holding "c" key w/same result. Let machine load w/OS9.2. Installed 10.3 disc into cd, set it as startup in "startup disc" control panel, restarted and this time after getting apple icon, after about 30 seconds, a black screen with white lettering overlaying another screen which asked me to hit restart or hold power button for several seconds. The black screen had rows of diagnostic codes with a bunch of technical stuff with the final line being," panic we are hung up".