No mini could boot OS 9 natively, and only G4 minis running OSX 10.4 Tiger could run OS9 apps in classic mode (removed in 10.5 Leopard). There are some who have

No mini could boot OS 9 natively, and only G4 minis running OSX 10.4 Tiger could run OS9 apps in classic mode (removed in 10.5 Leopard). There are some who have reported some success booting OS 9 using a custom ROM[0], but last I tried the process was finicky and missing some important features like USB mouse support. Of course this only works on G4 minis (2004-2005) which wouldn't be able to run OpenEMU, but there are other emulators that run fine on PowerPC macs. I've played a lot of Stella (Atari VCS) and KiGB (GameBoy) on G4 macs. The original Halo was PPC-native, and I spent a lot of time playing it on my Power Mac G5. I'm still kicking myself for getting rid of an iMac G4 that could boot OS 9. I kept the faster of my two not realizing I would be stuck with classic mode only, and lost that as well when I upgraded to Leopard. A 2009 mini has been my HTPC for years. That one does pretty well at retro gaming though I haven't tried Dolphin. It's barely playable on my 2011 mini (with integrated graphics). I might have a bit of a mini infestation... 0: https://forums.macrumors.com/threads/mac-os-9-on-macmini.2112087/ https://forums.macrumors.com/threads/mac-os-9-on-macmini.211...