This article from Scientific American describes one of the world’s very first numerically-controlled machine tools, a 3-axis Cincinnati Milling Machine Company “Hydro-Tel” painstakingly adapted for programmable electronic control two years before the first commercial silicon transistors:
THE M.I.T. system combines digital and analogue processes under feedback control to govern a milling machine whose cutting tool moves in three planes relative to the work piece. In this case the “model” of the object to be fabricated is supplied to the machine in the form of a perforated paper tape similar to that used in teletype systems. For a typical operation, 10 feet of tape will keep the machine busy for an hour.
The components of the M.I.T. system are grouped into two major assemblies. The first of these, called the “machine,” comprises the milling machine itself, the three servo-mechanisms employed to operate its moving parts, and the instruments required to measure the relative positions of these parts. The second assembly, called the “director,” contains all the data-handling equipment needed to interpret the information on the tape and to pass it on as operating commands to the machine. The director contains three major elements: a data-input system, a data-interpreting system and a set of three decoding servo-mechanisms.
Just another juicy bite of early Atomic Age history from our pals at Modern Mechanix. [Thanks, Lee!]