2 Sep
2004
2 Sep
'04
4:46 p.m.
At 06:15 PM 9/2/04 -0700, Bill wrote:
I have no idea what this is, but it sounds like
it's
made of discrete-transistor logic, and LOTS of it
Would be a cool find just for all those boards,
maybe something one could build something really
old-school out of (like the guy in Pittsburgh who
built a 4-bit discrete-transitor CPU in 1968 out of
a lot of scrapped logic boards). It doesn't sound
like you snagged it, though. :(
No I didn't :-( I was driving my wife's car and it was WAY too big to
fit in the car. However I told them to save it for me. It's heavy enough
that I don't think the hurricane will bother it since it laying flat on the
ground. I just finished tracing out one of the boards and it appears to be
a NINE-input Diode-Transistor AND gate. Three groups of three diodes with
each group's outputs tied together at the anodes and then each group tied
to the anode of another diode (so now nine diodes driving three diodes).
The cathodes of the three diodes are then tied together and connected to
the base of a single 2N1309 transsitor. (It's now a nine input NAND at
this point). The collector of the first tranistor is connected to the base
of the 2nd 2N1309 transistor. It's output is now a NAND function. I
haven't looked close at the other board but it looks like four buffers (one
transistor driving another one x 4). AKA four Darlington ampliers. The
boards look like new. It's a shame that I'll have to leave them there
through the hurricane. However I am going to call them and tell them again
not to do anything with the rack and to save it for me.
Joe
--Bill
--- "Joe R." <rigdonj(a)cfl.rr.com> wrote:
I got a call from a scrap place today and I
made a
quick trip out to see
what they had before the hurricane hits (it's due to
cross DIRECTLY over
the place's location so I don't expect the stuff to
be there come Sunday AM
since most of the stuff is out in the open). Got
some DEC core memory so
the trip was worth it. One of the things that I
found was a "Logic Rack"
made by (somebody) Research & (something). Sorry to
be vague about the name
but I was in a hell of a rush. Anyway it said that
they were a division of
XEBEC. The rack was ABOUT 8" or 10" thick and ABOUT
32" wide and ABOUT
seven foot tall and had HUNDREDS of small circuit
cards that plugged into
it. None of the ones that I saw had ICs, just glass
diodes, trqnsistors and
resistors. The cards are 4" long and 2 3/16" wide
with a 16 position CINCH
contact on one end. The transistors that I looked
at were all date coded
1969 but I saw what looked like it might have been a
date on the rack that
said 1973. Anybody know what this is?
Joe