iBook G4 running Mac OS 9 (Unofficially)

11/25/21

So, decided to start off this public random blog with this, neat. Crossing my fingers if this formats correctly too. If it doesn't, fuck shit in a dick. (Spoiler alert, it didn't. :())

I was contacted by a viewer of a video on my channel (about running Mac OS 9 on my iBook), as they wanted to do the same.

Heeeere comes the context though- the video on my channel was published in 2019- The video was recorded in November 2017. Halp.

Obviously having no clue on how to do this off the top of my head, and there being no official guide (as results on different systems are mixed), I had to go through older bookmarks I saved in 2017.

This whole ordeal is trial-error, there isn't any official guides for a reason. My research involved a lot of commands/tinkering on forum posts on respective forums MacOS9Lives!, ThinkClassic, and 68kmla.

With no modifications, inserting an OS9 install CD (Unsupported G4s version is preferred- find it on MacOS9Lives.) into the machine results in it appearing in Startup Manager, however upon booting to no avail - a grey screen. This is the normal behavior as iBooks in this era shipped with some OSX version (and was far into OSX at the time).

This is due to it detecting the computer information - model identifier, processor type, version, etc. and Mac OS 9 was last developed in 2002- when iBook G4s were produced in 2004. It's incompatible on a hardware level- because of how OS9 is, not the actual hardware itself.

(The G4 chip is leaps and bounds capable of running OS9.)

Open Firmware is your friend in this case and is extensively used. The only required thing to get OS9 to detect a valid system to boot on is to 'derp it' and make it identify falsely equipped with an older PPC G4/chip.

Open Open Firmware (lol) with the key combo Alt, Command, O, and F on startup immediately after the bong.

It should go to a command/terminal interface. My iBook is identified as PowerBook6,5- yours may be different and the following may not apply to you. If you happen to have the same model, eyy 6,5 gang. XD

We're now going to enter nvedit mode- a mode for entering a script of OF commands to be eventually saved in your computer's NVRAM. (If your computer has a dead CMOS battery- replace it, else you're going to have to do the following every. single. time. For the iBooks this doesn't apply.)

Simply type nvedit to enter this mode. Your cursor should jump below the field you just typed on. Type these commands exactly how they appear on screen:

" /cpus/@0" find-package if drop " /cpus/@0" find-device 80010201 encode-int " cpu-version" property then

" /cpus/@1" find-package if drop " /cpus/@1" find-device 80010201 encode-int " cpu-version" property then

You won't be able to see anything you're typing, have a decent keyboard with you. Or just be careful.

After these commands are entered, press Ctrl + C to exit nvedit mode, then type nvstore to save the above commands in NVRAM.

After that, you need to enable a setting so the script runs on each startup. Type: setenv use-nvramrc? 1 to enable it.

After that, you should be good to go- make sure your computer has a stable power source and then type reset-all to immediately reboot.

Do whatever method you did before to start up to the OS9 CD. Make sure it's the special patched "Unsupported G4s" version from MacOS9Lives- Normal installation discs won't work without other OF commands.

If happy mac goto success. You should be able to install OS9- with a catch.

Suggestion: The image file it installs on there using ASR (Apple Software Repair/Update) may not work when you boot from the HD- in my experience, copying the contents of the CD to the HD is preferred, and then manually sifting through extensions and control panels (in case any rogue ones get in the way).