
The Tech Model Railroad Club – Hackers at 30 - slyall
https://medium.com/backchannel/the-tech-model-railroad-club-3b06a3163563?hn=1
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nickhalfasleep
If you're in Boston on a night with a work session, you can call ahead and get
a look and perhaps a small tour. The System 3 electronics come down from the
original MIT designed intelligent blocking system, all the smarts are in the
layout, not the engines. This is nice because you have one layout, but many
people can bring their engines.

This is very different from the popular DCC (Digital Command Control = packets
superimposed over power from the tracks) that most large model railroads run
today.

In the near future model railroad equipment will be "IoT", with each engine
having a small embedded system and WiFi, creating an "Internet of Trains".

Model Railroaders like many hobbyists are willing to accept new technologies
into their toolkits. It's a relatively small, aging population, but the hobby
has many facets and readily accepting of new people.

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Animats
_" EAM room also had a particular keypunch machine called the 407. Not only
could it punch cards, but it could also read cards, sort them, and print them
on listings. No one seemed to be guarding these machines, which were
computers, sort of. Of course, using them would be no picnic: one needed to
actually wire up what was called a plug board, a two-inch-by-two-inch plastic
square with a mass of holes in it."_

This really dates me, but I've used and wired plugboards for an IBM 407
tabulator. The plugboards are about two feet square, not two inches.[1]

A 407 cannot sort cards; it has one card input hopper, one output hopper, a
printer, about twenty mechanical decimal counters, and relay logic. It can add
and subtract, but not multiply or divide. (With enough plugboard wiring, you
can, with great difficulty, do repeated adds to get a multiply, maybe at one
multiply per minute. Multiplication was usually done on a separate machine,
the 602A, which could do it much faster.)

Internally, it's not just relays. The counters are driven from rotating shafts
through clutches. The machine is full of shafts and bevel gears to distribute
the power from the motor. There's a built-in lubrication system, with tiny
tubes fed by a very slow oil pump.

A 407 itself cannot punch cards, but it has a connector into which a cable
from an IBM 514 Reproducing Punch can be plugged. The 407 can then send data
to the 514, which can punch cards. The connector alone is about 3" x 6", with
a 2 inch diameter cable.

This and the 602A Multiplier were IBM's last pre-electronic machines. Then IBM
started using tubes. The 407 remained in the IBM product line until 1976, and
many continued to grind on into the 1980s.

The 602A, the multiplier, is interesting because it's the foundation of IBM's
computer line. The 602A was electromechanical, programmed with a plugboard.
Then IBM introduced the IBM 603 electronic multiplier in 1946, which was like
a 602A, but used tube electronics instead of multiplying mechanically. Only
100 were made, to find out what it was like to sell and service machines with
tube electronics. Next was the 604, which was a bigger and better 603 and was
produced in quantity. It still had a plugboard program. This was followed by
the 605, another incremental improvement, and the Card Programmed Calculator,
which was a 605 plugged into a 407 and a 527 punch, which was a modified 514,
plus some additional memory units (10 numbers each, mechanical!). This was
almost a general purpose computer, but it still used plugboards. Then came the
607, which integrated all those units into a more coherent system.

There were a few more plugboard-wired machines, but the big step was the IBM
650, in 1954. This reused many of the parts from the 610, but was organized
like a modern computer. Finally, the plugboard disappeared. Programs were
stored on the magnetic drum. This was a useful workhorse machine; thousands
were made. Knuth learned to program on one. The 650 was very profitable for
IBM; it was the first electronic computer produced in volume.

Meanwhile, IBM had also produced the IBM 701 (1953) and the IBM 703 (1954),
which were full-blown huge tube computers with tape drives and drums. But
those were originally special purpose DoD projects; the 701 was called the
Defense Calculator. They were too expensive to be volume products. The 6xx
machines made money.

The point of all this is that there was no one big breakthough. IBM just kept
developing improved models. If there hadn't been ENIAC or UNIVAC or Bletchley
Park, the 6xx line would have been improved year by year into modern
computers. In fact, it was; the 6xx line led to the IBM 1401, released in
1959, the transistorized business computer that powered accounting for big
business for much of the 1960s. The 1401's architecture is weird, partly due
to the punched card legacy, but it got the job done.

[1]
[http://www.columbia.edu/cu/computinghistory/407.html](http://www.columbia.edu/cu/computinghistory/407.html)

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dekhn
I read the original version of this in Hackers almost 30 years ago. I didn't
really appreciate how cool the TMRC part of the book was until I started
learning about low-level hardware recently and realized that they were playing
around with telephone switches and automation really early.

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davelnewton
The TMRC and similar hack groups were some of my childhood inspirations.

