Tech Model Railroad Club

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The Tech Model Railroad Club (TMRC) is a student organization at Massachusetts Institute of Technology (MIT), one of the most famous model railroad clubs in the world, and a wellspring of hacker culture. Formed in 1946, its HO scale layout specializes in automated operation of model trains. In about 1948, the club obtained space in room 20-E-214, on the third floor of Building 20, a "temporary" World War II-era structure, sometimes called "the Plywood Palace," [1] which had been home to the MIT Radiation Lab during World War II.

The club's members, who shared a passion to find out how things worked and then to master them, were among the first hackers. Some of the key early members of the club were Jack Dennis and Peter Samson, who compiled the 1959 Dictionary of the TMRC Language and who some say coined "Information wants to be free".[2] The atmosphere was casual; members disliked authority. Members received a key to the room after logging 40 hours of work on the layout.

The club was composed of two groups: those who were interested in building and painting replicas of certain trains with historical and emotional values, and those who comprised the Signals and Power Subcommittee and created the circuits that made the trains run. The latter would be among the ones who popularized the term "hacker" among many other slang terms, and who eventually moved on to computers and programming. They were initially drawn to the IBM 704, the multi-million dollar mainframe that was operated at Building 26, but access to and time on the mainframe was restricted to more important people. The group really began being involved with computers when Jack Dennis, a former member, introduced them to the TX-0, a $3,000,000 computer on long-term-loan from Lincoln Laboratory.[3]

At the club itself a semi-automatic control system, based on telephone relays, was installed by the mid-1950s. In about 1964 this was replaced by a second system built around the 5 Crossbar telephone switch; lead designer for this project was Alan Kotok, by then a rising star on the design staff at Digital Equipment Corporation. Equipment for this effort was donated by the phone company via the Western Electric College Gift Plan. An extension to the basic control system allowed TMRC engineers to control switches on the layout. There was also a digital clock with relay switching, and an internal telephone system with external tie-lines, all built from telephone stepping switches and relays.

Digital Equipment Corporation donated 2 PDP-11 computers around 1970. One was eventually used to operate the club's major freight yard and the other was set up to perform user interface tasks, such as initial assignment of trains to throttles, and to throw turnouts. The computer replaced the keypad unit from an old keypunch machine originally installed by Richard Greenblatt.

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[edit] Vocabulary and neologisms

The TMRC spawned a unique vocabulary. Compiled in the TMRC dictionary, it included terms that became part of the hackers Jargon File, such as "foo", "mung", and "frob". Other substitutions include "orifice" for office, "cruft" for garbage, and "hack", meaning an elaborate college prank carried out by MIT students. This last definition is the basis for the term "Hacker".

[edit] System layout

By 1962 TMRC's legendary layout was already a marvel of complexity. The control system featured about 1,200 relays. There were SCRAM switches located at numerous places around the room that could be pressed to stop the trains' movement 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 the 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".

The layout is set in the 1950s, when railroads operated steam, diesel, and electric engines side by side. This allows visitors to run any engine they want without anything looking out of place.

Steven Levy, in his book Hackers, gives a stimulating account of those early years. TMRC's Signals and Power Subcommittee liked to work on the layout's relays, switches, and wires. The Midnight Requisitioning Committee obtained parts independently of campus procurement rules. The Signals and Power Subcommittee included most of the early TX-0 and PDP-1 hackers and the people who later became the core of the MIT AI Lab staff. TMRC was even offered a PDP-1 by 1965, although it had no space in which to install it and thus was forced to decline the gift.

Building 20, TMRC's home for 50 years, was demolished in 1997. The club was offered a new space in building N52, the MIT Museum building. Most of the layout was destroyed as a result. Construction of a new layout began immediately and continues as of 2009. The crossbar-based control system was moved into the new space and operated for two years but, as the new layout grew, the decision was made to replace it with an electronic equivalent. Known as System 3, this comprises around 40 PIC16F877 microcontrollers under the command of a Linux PC. An unusual feature of the layout is a model of the Green Building, an 18-story building which is the tallest structure on the MIT campus, replicated in HO scale and wired with an array of window lights which can be used as a display for playing Tetris, in reference to a legendary (but apocryphal[4]) MIT hack.

[edit] Famous members

[edit] References

This article was originally based on material from the Free On-line Dictionary of Computing, which is licensed under the GFDL.

  1. ^ http://www.eecs.mit.edu/building/20/
  2. ^ [1] docstoc.com citing Levy "3. All information should be free ... Number three, which dates back to 1959, is originally credited to Peter Samson [of TMRC]
  3. ^ Levy, Steven: Hackers:Heroes of the Computer Revolution. Anchor Press/Doubleday, 1984.
  4. ^ http://vadim.oversigma.com/games/gbt.html

[edit] External links

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