(no subject)

[Ethan Dicks]

On 7/31/07, Dave McGuire <mcguire at neurotica.com> wrote:
> On Jul 31, 2007, at 11:03 AM, Ethan Dicks wrote:
> >>> I wonder how much of an 8/i would fit in a current FPGA?
> >>
> >>    How much of an 8/i?  I think you mean "how many 8/is"!
> >
> > Ooh... there's something I haven't heard of before - a dual-core
> > PDP-8.
> >
> > That could be an interesting project.
>
>    The hardware is a no-brainer (I'm visualizing something like the
> DA11 interprocessor buffer but with appropriate architectural
> adjustments for the PDP-8)

Sure.  Makes sense.

> ..but...the software...thinking of that on
> an -8 just makes my head hurt.

Well.... I remember a particular dual -8/m configuration at Ohio State
in the Veterinary College.  It was  a mass spectrometer rig for
analyzing drugs in race horse urine.  One -8/m was always connected to
the mass spec, the other to a tape drive, with 4-6 Diablo RK03-type
drives and a dual-ported disk controller.  It wasn't hot-swappable -
you manually selected which drives responded to which CPU, then
rebooted the CPU that needed to access the "new" drives.  With OS/8, a
reboot is rather quick.

If you wanted something more sophisticated, one could consider running
an updated RTS-8 with OS/8 as a task for each CPU.  The RTS-8
executive could handle resource locking and sharing.

It would still be a feat, but I think it's doable.

-ethan