Retro Again – G4 Mac Mini Running Mac OS9

I’ve just got a G4 Mac Mini up and running Mac OS9. About six months ago I gave away a MDD (Mirror Disk Door) Mac, that I’d been keeping around in order to install Mac OS9. I got fed up of it hanging around and since it would not boot onto Facebook Marketplace it went But about a month ago I spotted a post in the r/vintageMacs subreddit, where somebody had started buying old G4 Mac Minis, upgrading them with SSD, then installing a hacked version of Mac OS9 that installed on them.

The G4 Mac Mini was only ever shipped with OS X. It ran Classic, but would not boot Mac OS9. Turns out [a few clever people on the macos9lives forum had swapped out the rom for the G4 Cube and messed about with it to boot Mac OS9. There’s an ISO of an installer for the unsupported G4 Mac Mini on that forum.

This is now the fastest G4 that will run Mac OS9. I guess there’s the G5 Mac Pro, but as of yet nobody has done this one, and I guess it will never happen as that would require a new kernel?. However, there are plenty of G4 Mac Minis out there for next to nothing.
These have IDE discs (the Intel Mac Mini moved to SATA). These clever people have also searched mSATA/IDE adaptors. There are so many of these available for next to nothing. I guess meant for somebody to plug into their old laptop they want to keep going.

So on eBay I went and got an Integral 128GB mSATA Internal SSD together with a Chenyang SA-106 CY mSATA Mini PCI-E SATA SSD to 2.5 inch IDE 44pin Hard Disk Case Enclosure. I removed the plastic case to increase air flow though.


I initially struggled as I could not get the optical drive to work. At first I thought it was because a few posts said the drive on the G4 Mac Minis would not recognise a 700mb cdr. So I found a pack of (expensive!) 650mb CDrs. But these failed too. However, I remembered that I had a cheap IDE-USB adaptor that I bought (for reasons I do not remember). I used OSX and Super Duper to create a bootable partition on a USB connected drive (for some reason two old Firewire drives I had would just not work). I then booted from these and used a tool called iBored to image the install ISO to the original drive still in the Mac. I then booted from the installer on the original disk, installed (using the Apple Restore IMG on that ISO) to the adaptor connected mSATA drive, swapped the drives over and fairly soon I was running Mac OS9 on that G4 Mac Mini.

Of course it was not as simple as that. Turns out my Mac Mini was the 1.5Ghz one. This has extra difficulties that the earlier Macs did not. Graphics was a pain. VGA allowed me to run my Dell 1920×1200 at fill res. But under DVI the screen was corrupted. But I found an extra driver on the macos9lives forum that solved that for me. Well nearly as I cannot go above 1900×1080.

The optical drive still did not work. I bought a new one that also failed as it was a generic rather than an Apple device. I thought only the OldWorld Macs needed those. I even dug a drive out of an old Macbook Pro. Which also failed. But I then found out that Mac OS9 will boot from a IDE drive connected via this USB/IDE device. I guess as it presents itself to the Mac as an IDE device (in the Mac OS9 System Profiler it is listed as an ATA device). I eventually had to install a second time and this made swapping the drives redundant and so I had no need of an optical drive.


Configuration on install

Mac OS9 is fine with DHCP, although the fairly dumb “registration” process asks you all sorts of daft questions that perhaps were relevant then, but are fairly archaic and annoying now. e.g. POP server, “do you want to connect via modem” etc..

Sharing files

For sharing Netatalk is an AFP server (remember Apple have deprecated this in favour of SMB3) that runs fine on Debian. Rather than install it using APT, which then pulls in all sorts of stuff to get zerofconfig network discovery working Avahi, mDNSResponder etc.) I used a Docker image. I could not get authentication working, so I had to change the afp.conf to allow anonymous discovery. Then creating an SMB share of the same folder I can easily share files.