Subject: Re: None
To: None <dgilbert@jaywon.pci.on.ca, john@iceberg.demon.co.uk>
From: Olaf Seibert <rhialto@mbfys.kun.nl>
List: amiga
Date: 12/04/1995 13:09:51
> How did they run Unix on a 68000 processor? Did it have no virtual
> memory? If so maybe old versions of SunOS could run on any Amiga?

I recall that there was a technique using two 68000 processors that is
different from the one already mentioned. This techique would use the
first 68000 to run most code, and then when it hits a bus error it is
simply stalled. The second processor fixes up the mess and then lets
the first one continue.

Neat little hack. Sounds somewhat more plausible too than the "one
instruction behind" trick. Not all instructions take the same time so I
don't see how that could be managed reliably. And one would need to
take into account the (small) prefetch, handle the data being written
by the lagged cpu, somehow get them to switch roles (which involves
backing up the original first cpu an instruction or two)...

-Olaf.
--
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