The only thing you need to achieve pre-emptive multitasking is interrupts and the ability to cleanly save the current CPU state. The 68k lacked the ability to

The only thing you need to achieve pre-emptive multitasking is interrupts and the ability to cleanly save the current CPU state. The 68k lacked the ability to resume with full state intact after a bus fault, which made an off-chip MMU painful (but there was one - the MC68451[1]), but this doesn't affect the ability to do pre-emptive multitasking at all. AmigaOS famously did have preemptive multitasking - we used it to mock PC and Mac users with for years. [1] https://en.wikipedia.org/wiki/Motorola_68451 https://en.wikipedia.org/wiki/Motorola_68451 Note that to do full virtual memory with a 68k, Motorola proposed using a second 68k to handle page faults due to a design flaw: https://retrocomputingforum.com/t/correcting-errors-by-duplicating-processors/2453 https://retrocomputingforum.com/t/correcting-errors-by-dupli...