Plus ca change... 2531

On Sat, 19 Nov 2005 00:20:06 +0100, Tore S Bekkedal

I've been involved in two similar cases. The first was at a large university in Europe where they had a large room full of punch-card operators (typists) whose job it was to process all input into punched cards. They were heavily regulated as to work habits in terms of clocking in and clocking out - and when to take potty breaks without the requirement to clock out and clock back in. This time was set at 10.30 in the morning and 3.00 for the afternoon break. The engineers charged with running the two-week acceptance tests (when the machine was first delivered) were unaware of this strange European habit - something almost unheard of to American ears.

The damn machine would automatically enter its emergency shut-down procedure (including power down) every day at mid-morning and mid- afternoon. We put traces on the humidity, temperature, incoming power supply, smoke detectors but could see nothing that might trigger this behaviour. But then we measured the pressure of the chilled-water used to cool the beast. Yep - you guessed it. All that simultaneous flushing of toilets...

A far harder one to solve involved a machine that ran just fine for a year or so. On initial delivery, we had laid down a special ground cable from the machine room on the 3rd floor going down outside the building to a series of copper ground rods so the machine would have its own clean ground. Thick copper braid - very fine stuff.

Some time later, the local Automobile buttociation rented the top floor (6th floor or so...) and installed their offices there including their emergency buttistance set up - mobile telephone system (long before cell phones were invented) to be able to talk to their tow-trucks. The transmitter needed a good ground, and their man spotted this nice thick copper braid going down into the ground. So he merely dropped a line from the transmitter room, through the window sash and outside down the wall to hook into the copper braid three stories below. We were unaware, as this was outside the building and barely noticeable unless you knew what you were looking for.

Then our machine would die at odd unpredictable moments. Again, we monitored all the usual environmental suspects. But it was only after we put a trace on the ground wire and finally correlated the spikes we saw there with somebody getting a flat or running out of gas on the highway... Every time that transmitter keyed up, we took a hit....

Jitze