>>> The introduction of "supervisor mode" was a mystery.
>> It was introduced to try to get DEC to adopt it for its new
>> machines, I thought, since VMS needed it.
> I'm skeptic it because VAX does not have it.

...huh??  Sure the VAX has it.  The VAX has four privilege modes: user,
supervisor, executive, and kernel.  VMS used all four: memory says it
was user for most code, supervisor for the CLI, executive for the
filesystem, and kernel for, well, the kernel: scheduler, VM, device
drivers, etc.

Unless the "supervisor mode" under discussion isn't a privilege level
wedged in between the usual userland and OS-kernel modes (which latter
is called "supervisor mode" by some other CPUs, such as the 68k, that
have only two privilege modes).

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