I may be wrong, but i thinj the easiest way to see if your G3 is supported is 1) Bronze keyboard and 2) USB ports. This is what i am running 10.3.1 on. I did not install 9 first, i just installed from the panther disk. You do need to make sure your firmware upgraded. I had problems installing OSX on 2 computers that ran OS9 fine. it turned out to be bad RAM. OSX seems to be particularly finiky about RAM. I had one computer that ran for 4 years in OS9 without difficulty, but as soon as i installed X, the same RAm caused issues. SO, i would also take out any 3rd party RAM and seeif it helps