15 Jul
2002
15 Jul
'02
8:54 p.m.
On Mon, 15 Jul 2002, Loboyko Steve wrote:
This does look like a Mark-8 that's been modified
(rather craftily) to
use a plug backplane.
It appears that the builder also created a number of custom boards which
are mounted to the Mark-8 boards.
I'll bet the control socket on the front is where
the Front panel (or
maybe EPROM or ROM or maybe even diode?) board would go. Keep in mind
that ROMs of any kind were very expensive in 1974-6 for a home budget,
and no one had programmers.
Or even a toggle switch board. Using a socket on the front panel adds a
lot of versatility. I imagine those boards are missing simply because they
were the easiest for someone to scrap. Toggle switches and LEDs are always
useful, and someone not knowing what a treasure this system is would have
had no problem at all with reusing those parts.
If you actually intend to get this going, I'd be
concerned about the
Molex sockets. They are constructed using PURE EVIL and were unreliable
when new. Judging from the chips utilized (some no-name chips) and the
sockets I suspect that this was built by a very skilled hobbyist,
probably an engineer or senior technician working at home.
When you look at the custom boards, and the fact someone took the time to
bundle up the wiring to create harnesses, the builder had to be someone
with a lot of design experience. The custom backplane took someone handy
with machine tools too.
I'd sure like to know who built this thing...
-Toth