11 Sep
2015
11 Sep
'15
7:38 p.m.
On 09/11/2015 11:31 AM, Cory Heisterkamp wrote:
Are there any operational G-15's out there? Seems
like this would be a good
model to restore/demonstrate that doesn't come with all the usual baggage
of a first gen machine (exotic power, A/C requirements, thousands of tubes,
etc). -C
Supposedly one in Australia is at least close to operational.
I tried to help get a G-15D running at Washington University
in about 1972. it was one of those NASA surplus deals, "you
pay the shipping and it is yours". We got the G-15,
typewriter and typewriter control box and several huge boxes
of documents and paper tapes. It wasn't that hard to get
power run to the machine, we had a lab available that was
proven to be able to handle the heat load. But, then, it
didn't seem to work. I think the relays in the typewriter
control had dirty contacts, and there were a LOT of relays
in there! The thing had 300 tubes of dubious quality.
Finally, I determined that the drum was badly scored, there
were several tracks that were scored down to the brass. So,
obviously, no existing program could be expected to run,
with several shot drum tracks.
This is one of the major problems with the G-15, there was
VERY poor protection of the drum from dust. They had a
formed aluminum cover, but the cable bundle went through a
hole with caterpillar grommet around it, so plenty of room
for dirt to get in.
The diode boards were paper-phenolic, and almost certainly
would get more brittle as they aged.
But, yes, it was a fairly simple machine, I don't think you
could strip a tube computer down much further than the G-15
and still have it do useful work.
Jon