TMRC
TMRC
By 1962, TMRC's legendary layout was already a marvel ofcomplexity (and has grown in the thirty years since; all thefeatures described here are still present). The controlsystem alone featured about 1200 relays. There were scram switches located at numerous places around the room thatcould be thwacked if something undesirable was about to occur,such as a train going full-bore at an obstruction. Anotherfeature of the system was a digital clock on the dispatchboard, which was itself something of a wonder in those bygonedays before cheap LEDS and seven-segment displays. Whensomeone hit a scram switch the clock stopped and the displaywas replaced with the word "FOO"; at TMRC the scram switchesare therefore called "foo switches".
Steven Levy, in his book "Hackers", gives a stimulatingaccount of those early years. TMRC's Power and Signals groupincluded most of the early PDP-1 hackers and the people wholater bacame the core of the MIT AI Lab staff. Thirtyyears later that connection is still very much alive, and thisdictionary accordingly includes a number of entries from arecent revision of the TMRC dictionary (via the Hacker JargonFile).