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SeattleVet

(5,627 posts)
6. I worked on systems that used similar wiring.
Sun Sep 9, 2018, 06:31 PM
Sep 2018

Honeywell DDP-124, which used a Friden Flexowriter as an input device (with had a 5-level paper tape reader/punch attached). This was a LARGE system - it had the expanded memory (all the way to 16K, using hand-woven core memory modules), and a 5Mb disk drive the size of a washing machine, with heads the size of a quarter that flew a visible distance above the platters. Full of mechanical relays, and used a slightly larger 'guard platter' on the bottom, with spaced notches in it for timing via a light pipe and sensor.

When we replaced that system, everything had to be listed in a government surplus list in case any other agency might have a use for any of it. The Smithsonian contacted us and asked for the Flexowriter, since they didn't have one in their collection. So, somewhere in the 'Nation's Attic' is a piece of antique computer equipment that I maintained for a few years!

Also worked on a (very large) custom-made system that had 10 7-foot-tall racks, all hardwired, 5 to a side, with a walkway between the two sides so we could get inside the machine to work on it. 2 of the racks were stacks of power supplies. It had 1"x4" solid copper bus bars for the 200 Amp, plus and minus 5 and 12 volt power supplies. One day someone dropped a screwdriver and it rolled onto the bus bars. We got a loud bang and bright flash, and all we ever found was a piece of the plastic handle halfway across the room. The system never even hiccuped. This one used 7-layer, 14" square fiberglas PC boards and all RTL logic. Someone put a board on an extender one day to get some readings, and got it in crooked. The circuit that shorted out on that board burned a quarter-sized hole through the entire board.

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