The vanilla 68000 can definitely use an MMU. I think you're conflating "can handle a general fault" and "does address translation". Some PDP-11s ran Unix just

The vanilla 68000 can definitely use an MMU. I think you're conflating "can handle a general fault" and "does address translation". Some PDP-11s ran Unix just fine with MMUs that didn't generate page faults (they just did address translation and bounds checking). You can even do fault handling on the 68000 if you're willing to limit it to instructions that are known to work or that you can throw away (e.g., XOR, which is what Sun used for its stack probes). I designed an MMU for the 68000-based Atari ST (it did translation and bounds checking in an interesting way), and we implemented it in the silicon. A Unix for it never happened, unfortunately. https://dadhacker-125488.ingress-alpha.easywp.com/how-the-atari-st-almost-had-real-unix/ https://dadhacker-125488.ingress-alpha.easywp.com/how-the-at...