Machine control, or numerical control, also known as computer numerical control (CNC), is the automated control of machining tools (drills, boring tools, and lathes) by means of coded programmed instruction. Once the coded program instructions are loaded, a CNC machine can process the material to specification without an operator.
Tektronix started machine controls in the early 1970s by designing equipment for its own internal use. Existing controllers available were very large with tube circuitry, drifted, and were hard to maintain.
The Tektronix controller was a TTL (transistor transistor logic) digital controller. It was basically a discrete logic state machine. Math functions such as circular interpolation were all designed in digital circuits. It was small, accurate and reliable. Tektronix used several of these controllers in the model shop for quite awhile.
Tektronix also developed a tape verification product that the programmer used to create the program. The resulting program was punched onto a paper tape and the accuracy was checked by running the tape and viewing the tool path on a Type 611 display.
The results were a superb system and a new market for Tektronix opened up. This January 8, 1971 TekWeek features the introduction of the 1701 and 1702 numeric control systems. Click on the image to view the PDF.
This excerpt is from the 1971 Tektronix Catalog. Click on the image to view the PDF.
This March 5, 1971 TekWeek features the introduction of the 1704 Machine Control Unit and 1791 Program Verification Unit at the Western Metal and Tool Exhibition.
The October 15, 1971 Tekweek features a report by Bill Walker at an Area Rep meeting. This excerpt mentions diversification efforts by the company including machine control.
This January 28, 1972 TekWeek/TekTalk describes how numeric control in the Model Shop significantly speeds up fabrication. Click on the image to view the PDF.
The museum has a 1703-2 machine control unit on display. It consists of a 611 Storage Display Unit, a paper tape reader, and the machine control unit.
The construction is a number of smaller PCBs inserted into a backplane which is hand wire-wrapped.
Here is a closer view of the backplane hand wire-wrapping.