4 Jul
2015
4 Jul
'15
8:08 a.m.
On 07/03/2015 06:59 PM, Johnny Billquist wrote:
I find it hard to believe it was a plain 68K in there.
That CPU have some
serious issues that makes it close to impossible to implement virtual
memory or proper usermode protection.
(Yes, it can be done, but the amount of hardware required means most did
not. I think SUN did it with their own MMU, and an extra CPU in there.
Trying to remember who else - I seem to remember one other company who
actually used a plain 68K, and it was not Unisys.)
Essentially, the 68010 is pretty much the minimum of processor needed to
make a sane system to run Unix on.
I've got a few Torch boards which use a plain ol' m68k (either 8 or 10MHz
depending on the variant) and they were capable of running Uniplus+.
There's very little other logic on the boards, although they do have a
local Z80 (they were designed to run Torch's CP/M variant too), so I
suppose it's possible that could be employed somehow to provide the
necessary support for the m68k.
Jules