This is a great comprehensive article on the "why" and there are good YouTube videos on the "how." What the article is missing that makes it even better is putting an SSD in which makes it even faster of course. You can get an untested Mac mini G4 for about $60 on eBay and the rest of the parts (SSD, PATA-mSATA adapter, RAM if less than 1 GB, power adapter, any missing screws, clock battery, etc.) will run you another $60 to make the ultimate Mac OS 9 machine. If you're comfortable taking things apart and putting them back together it's not too bad.

A quick tip: be sure to reset the PRAM with command-alt-p-r holding down during restart until you hear 3 chimes. Then while the machine is booting hold down command-alt-o-f and type "reset-nvram" and then "set-defaults" and then "reset-all" (all of this is in open firmware) before installing Mac OS 9 to make sure firmware is in its original state.

I came across this idea of SSD upgrading and installing Mac OS 9 in April 2024 and bought three broken ones to build one for my son. [0] When the first one worked, I ended up figuring, why not just finish the other two and sell them on eBay?

That led me into a hobby business. I've now cleaned, upgraded with SSDs, and sold about 70 of them. The "business" basically breaks even, so it truly is a hobby. In fact I invested so much in inventory buying 90 of them in a lot at the end of 2024 that I am negative right now. I will probably turn a slight profit in 2025. But it's fun and if you want you can buy one from me at: https://os9.shop

Sorry for the self-promotion, but very relevant!

0: https://x.com/davekopec/status/1795872492386398683

The depth of this article is wonderful. The PowerPC line did have lots of good things going for it, and the Mac mini G4 is a good example of how much you can get done with modest space, power and heat.

I'm still using Mac mini G4s in several places, both for Mac OS X (legacy Final Chop) and as small, low power servers running NetBSD.

There are really only two drawbacks to the Mac mini G4, in my opinion:

Gigabit ethernet would've been a dollar or two more? Being stuck with 100 Mbps, or around 300 Mbps if one uses a gigabit USB adapter, isn't fun.

If the DIMM slot could take 2 gig DIMMs, this'd be a perfect machine. Other PowerPC Macs could take 2 gigs - heck, even the older PowerPC 604e Power Macs 9500 and 9600 could take 1.5 gigs - so being limited to 1 gig is a bit unfortunate, especially considering that 2 gig DDR DIMMs are a thing (later Xserve G5 units could take 2 gig DDR DIMMs).

Still, the Mac mini G4 is the only computer aside from SBCs that I've bought brand new, and I have always been very happy with my decision.

I have a 2002 TiBook[1]; it officially supports MacOS 9.2.2, but also every OS X release up to 10.5.8. I've been surprised to find that the retail copy of StarCraft that I bought in 2009 not only includes an OS X build, but also supports PowerPC!

[1]: https://www.rollc.at/posts/2024-07-02-tibook/

I'm not sure if it can be made to run m68k apps "natively", but on the other hand you can emulate just about any classic MacOS in a modern browser[2].

[2]: https://jamesfriend.com.au/pce-js/

While the Mac mini is nice due to its size, personally, if you're choosing a hardware over emulation, I'd rather have an iMac G4 simply because of the aesthetics. It's amazing how well that design holds up even today.