TMRC

/tmerk'/ The Tech Model Railroad Club at MIT, one of the

wellsprings of hacker culture. The 1959 "Dictionary of the

TMRC Language" compiled by Peter Samson included several terms

that became basics of the hackish vocabulary (see especially

foo, mung, and frob).

By 1962, TMRC's legendary layout was already a marvel of

complexity (and has grown in the thirty years since; all the

features described here are still present). The control

system alone featured about 1200 relays. There were scramswitches located at numerous places around the room that

could be thwacked if something undesirable was about to occur,

such as a train going full-bore at an obstruction. Another

feature of the system was a digital clock on the dispatch

board, which was itself something of a wonder in those bygone

days before cheap LEDS and seven-segment displays. When

someone hit a scram switch the clock stopped and the display

was replaced with the word "FOO"; at TMRC the scram switches

are therefore called "foo switches".

Steven Levy, in his book "Hackers", gives a stimulating

account of those early years. TMRC's Power and Signals group

included most of the early PDP-1 hackers and the people who

later bacame the core of the MIT AI Lab staff. Thirty

years later that connection is still very much alive, and this

dictionary accordingly includes a number of entries from a

recent revision of the TMRC dictionary (via the Hacker Jargon

File).

[Jargon File]