On: PowerMac 6100 Upgrade Guide (2000)

[perardi]

I believe that Mac OS X only ran on “New World ROM” machines.

https://en.wikipedia.org/wiki/New_World_ROM

(Could be wrong about that—that was a long time ago.)

[kalleboo → perardi]

Early versions of OS X did run on Old World Macs, I remember running it on my 7500. I think the limiting factor was the Mac had to have Open Firmware, which started with the PCI Macs.

https://eshop.macsales.com/OSXCenter/XPostFacto/Framework.cf...