Several operating systems on 286 (eg Xenix, Coherent, OS/2) used its MMU for multitasking and memory protection. See https://en.wikipedia.org/wiki/Intel_80286#Protected_mode
The 286 protected mode did not allow for a 32-bit flat address space and was heavily half-baked in other ways, e.g. no inbuilt way to return the CPU to real mode without a slow and fiddly CPU-reset.
[dead]
The 286 protected mode did not allow for a 32-bit flat address space and was heavily half-baked in other ways, e.g. no inbuilt way to return the CPU to real mode without a slow and fiddly CPU-reset.