Ask Max: Installing OS 9 on later model G4s
I just bought from PowerMax a refurbished Mirrored door G4 (dual 867). I installed OS 10.3 but I also need to install classic. I have a retail version of 9.1 (bought years ago but never used) that I'm trying to install. The G4 won't let me start-up from the 9.1 CD. I've held the C key but it just opens to X. If I click on the install icon on the 9 CD it tells me that 9.1 is already installed--but it's not. How can I get 9.1 installed?
This is a common problem for the later model G4 computers. They will only boot off a Mac OS 9.2.2 CD and no other version will work, not even 9.2.1. The bigger problem there is that Apple never made a 9.2.2 CD that you could buy. They only came with new computers. The fastest way for you to get OS 9.2.2 on your G4 computer is to purchase the original CD pack that came with that computer.
There is another way to get your copy of OS 9.1 on your computer but it's complicated. You will need another Mac that has Mac OS 9 on it and a working original FireWire port (This cannot be done with a B&W G3 tower). Also you are going to need a 6 to 6 Pin FireWire cable, the kind that you would use to connect a FireWire Hard drive to your computer.
Boot up the Mirrored Door G4 with the "T" key held down. This will put the computer into Target disk mode and display a big yellow FireWire symbol on a blue screen. Now connect the two Macs with a FireWire cable and boot your second Mac from the OS 9 CD by holding down the "C" key. When your second Mac boots fully of the OS 9 install CD you should see both the hard drive of the second Mac and the Hard drive of the Mirrored Door G4. Run the installer and install OS 9 on the Mirrored Door G4's hard drive. When the installation is done, restart the second Mac and hold down the "Option" Key. The boot loader will appear and you can select the Mirrored Door G4's hard drive. Click on the right arrow button to boot off the selected drive. When you boot up, you can update the OS to Mac OS 9.2.2 from software update. You may have to upgrade several times to get to 9.2.2 but after you do you just need to restart both computers without the FireWire Cable. You now should be able to boot into OS 9 or X on the Mirrored Door G4 and Classic should now work within OS X.