The Campus - Relocating The Computer

It wasn't a large campus - maybe half a dozen blocks wide and long - and a fair amount of green space. If I recall correctly, maybe 3 or 4 classroom buildings with a dozen or so teletypes. Wiring between the computer and the various teletypes was simply long runs of twisted pair bell wire, running between the buildings.

I never saw the wires themselves, I was never into that. I was so deep into the computer itself, some nights I didn't leave the Computer Room til Tom (the operator) came in at 6:00 and chased me off. As a Student Assistant, I had the use of a small SA room (later a small office), so I didn't have to leave the Computer Center. But getting computer time between 7:00 and noon or so was pretty unlikely, and I did go to class too.

Anyway, the teletype wiring became a key player in this story. In the old Computer Center, there was the computer, and somewhere in the back of the computer was a box where a couple loops of bell wire was connected. Connected to the bell wire, in one or two loops, were the dozen or so teletypes.

Now this connection of bell wire directly to computer was not stable - there were occasional breakdowns, and some teletypes never worked consistently. Depending upon how the individual teletypes were connected, and which teletypes were on at the same time, you would have significant current or voltage fluctuations, which resulted in instability. A teletype turned on could affect a whole loop, and other teletypes.

When the Computer Center was relocated, from the middle of campus to one end, rewiring the new location was a major effort. New bell wire was run from each of the 3 or 4 classroom buildings, to the new location. As part of the move, Tom (the student), who was an electronics wiz, was asked to design and build a custom switch for the teletypes, to stabilise the current / voltage levels between the teletypes and the computer. So he did, and his custom unit, using a massive array of relays, did an awesome job of making both the current and voltage flowing thru the bell wires consistent.

As part of the design, Tom included one extra teletype connection, a hard terminal that did NOT go thru the relays in his custom switching unit. He had to have some unit to test with, that did NOT go thru the switch, after all.

We placed a single teletype just inside the door of the SA office, a scant 3 feet away, and connected it to the hard terminal in the computer. I'm sure that he demonstrated his switch, and the hard terminal, to Harris and the other adults. My guess is that it simply slipped their minds. A lot happens in a year, and as teletype instability became a memory, the teletype control switch became just another box in the Computer Center.


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