On 6/26/2015 20:31, Larry Sheldon wrote:

On 6/26/2015 19:44, Joe Hamelin wrote:

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On Fri, Jun 26, 2015 at 5:40 PM, John Musbach <johnmusbach1@gmail.com> wrote:

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P.S. If there was any way to get a tour inside of there at least I'd totally sign a NDA for that. :) Never been inside, let alone near, a CO before.

http://museumofcommunications.org/?page_id=12

There are three parts of a #5 Crossbar switch for which I have a special fondness:

The exerciser routine--late at night in a (sometimes spooky) dark, quiet office you hear a clicking noise that come up from behind you and passes on into the distance in front of you, After a bit, you realize that it is approaching again....and again, each time a little lower down as the exerciser operated EVERY crosspoint in the office, one at a time.

The Transverter -- a monument to the Perfect Kludge.

The Trouble Recorder -- a card-punch that punches a card every time a call fails, to record all of the equipment (and some other stuff) that was involved in the call. The cards were BIG (4 inches by 16 inches, maybe) and I have no idea what the number of possible hole locations was and had printed on-the card a cryptic notation as to what each hole meant. The most interesting thing was the fact that there were notations on both sides of the card--a given hole had two meanings depending on which side of the card the hole had been punched it. Thye first thing you looked at was two holes (I forget what one of the markings was, bit one hole said "AMA" on one side and "Turn Card Over" on the other side. (I was not a switchman, so the number of errors possible here us huge.)

I didn't realise that there was a relevant picture in the museum set -- http://museumofcommunications.org/wp-content/uploads/2012/06/DSC_7116-1024x6... shows severak of those cards on shelves, and in the near fore-ground is the bins used for sorting cards for further investigation (one of the "investigation" steps was to take a deck of cards for a similar failure and hold the deck up to the light to see if a single piece of equipment had been involved in every failure (hole goes through the deck).

-- sed quis custodiet ipsos custodes? (Juvenal)