# First-Hand:Chad is Our Most Important Product: An Engineer's Memory of Teletype Corporation

Submitted by Jim Haynes

## How it all started

When I was growing up in a small town I thought it was an awfully boring place. Now I realize that I had some opportunities that probably would not have been available in a larger city. For one thing, it was possible for a kid to hang out at the newspaper office, telephone office, telegraph office, or radio station and watch a Teletype machine in operation. Things were slow enough that the people who worked there usually had time to answer questions. When I wanted to understand how a Teletype machine worked the wire chief at the telephone office let me borrow the “green book”.[1] After reading all about selector cams and swords and code bars and pull bars I could drop in to the Western Union office where the manager, a friend of the family, let me play with a little-used printer and see in action all the parts I had read about.

The author operating W5YM in 1957

Another advantage to living out in the sticks was that television arrived very late. This allowed a pretty good news stand to remain in full operation through most of my teen years. Jack’s News Stand carried several magazines of interest: Radio-Electronics, Radio & Television News, and the amateur radio magazines QST and CQ. Hugo Gernsback’s Radio-Electronics ran a series of articles by Edmund C. Berkeley about digital computers, which gave me an early introduction to binary arithmetic, Boolean algebra, and logic circuits. Jack’s also subscribed for a while to a Western Union service that brought baseball scores on a ticker. This was one of the old-fashioned tickers with the mechanism under a glass bell jar. They made a lot of noise even when not printing anything, as the principle involved sending polarity reversals at about 20Hz that operated a ratchet to drive the print wheel. These tickers had long been retired from stock market service as too slow; but they were still fast enough to keep ahead of the baseball games. Western Union hated to throw anything away.

In those days (circa 1953) Wayne Green had an occasional column in CQ magazine on the subject of amateur radioteletype; and I happened to see one of them.[2] Until then I had never imagined that a teleprinter was something an individual could possess and use to communicate via amateur radio. Although I didn’t have an amateur license at the time I had an uncle who was a ham. He kept me supplied with old copies of The Radio Amateur’s Handbook which I devoured. Ham radio looked like a lot of fun; getting a license was something I always intended to do someday.[3]

## Go West, young man

Phoenix was quite different from Chicago. The climate is fairly pleasant for 8 or 9 months of the year and unbearably hot the other 3 or 4 months. For that reason most of the growth of the city had taken place in recent years, after the large-scale deployment of air conditioning. Hence it was mostly a low-rise city, very spread out, suburban-looking, automobile friendly, and new. The G.E. plant was near the northwestern edge. I rented a house on a large lot a few miles from the plant. There were cotton fields nearby; and in one field was a weatherbeaten sign saying a big shopping center would be coming soon.[52] In my yard were several grapefruit trees with fruit all over them. At first I assumed the fruit grew year round; later I learned it all got ripe all at once but you could just leave the fruit on the tree and pick it when you wanted to eat it. At the supermarket down the street the grapefruit was all from Florida.

In Ran Slayton’s department at Teletype we had hired Jim Eller as a technician. He showed up in Phoenix working for Motorola and stayed with me for a little while until he found a place of his own. Jim was responsible for introducing a couple of neologisms into our pre-lunchtime vocabulary. “Djeet?” (Did you eat?) and if you replied, “No” then the response was “Squeet” (Let’s go eat). I took the responsibility to carry these into G.E.

I saw Ray Morrison one more time. He had retired and moved to Sun City, next to Phoenix.

The corporate culture and working environment at G.E. were quite different from anything I had experienced at Teletype. The general manager of the department was a Dr. so-and-so. Teletype people had seemed fairly disdainful of PhDs. There seemed to be a belief that the experienced mechanical designers and the experienced people on the shop floor had a knowledge base far more useful than anything represented by the academic distinction of a doctoral degree.[53] G.E. seemed to have considerable pride in and reverence for its doctors. I suppose in the Bell System as a whole Teletype was somewhat an anomaly in this respect, considering how PhD-heavy Bell Laboratories was. At G.E. managers were called managers; that title carried a certain reverence. I was to learn over a period of time that there was a sort of cult of management that pervaded the company. The first-level managers of engineers tended to be engineers themselves; but at higher levels it seemed as if management was considered a science in itself, and that a a G.E. manager could manage anything, from light bulbs to locomotives to computers.[54] Another G.E. doctrine, quite a good one I thought, was that engineers should be able to remain engineers if they wished, and not be forced into management to advance in their careers. There were a few engineers in the plant with the title of “consulting engineer.” They were top technical experts who could be consulted on problems that were beyond the ability of the rest of us.

The engineers’ offices were cubicles, most holding three or four people. Labs were out in the plant, quite a distance away. Perhaps the circuits people had labs in their office areas. In those days a computer was so big that I guess it wasn’t considered practical to have the designers’ offices in the midst of their labs. Also computers were awfully noisy with all the fans and blowers, so it would be hard to work around one. The circuit designers, logic designers, and power supply designers were all separate groups and didn’t have much mutual communication. Unlike Teletype, G.E. didn’t like to make mechanical things. Cabinets and logic frames and front panels were necessities; but otherwise we were told as much as possible to use parts that could be bought ready-made. Drafting was done in a central department. Control panels were made using numerically-controlled milling machines. Tapes to control the machines were prepared in the drafting department. It was a tedious and error-prone process. An engineer told me the story of the control panel for his project. When the machine had finished there was an unintentional extra hole. The draftsman reworked the machine control tape several times, each time getting the unwanted hole to move but not eliminating it. Eventually one of his changes moved the hole near the edge of the sheet, where the metal would be bent down and the hole would be out of sight. They decided that was time to leave well enough alone.

What I came to consider most significant, although it dawned on me gradually, was the coffee system. Teletype, perhaps through wisdom, perhaps through ignorance, kept the cafeteria open all morning. The different engineering groups would go for coffee at staggered times; but almost all the people in R&D passed through the cafeteria every morning. There was a lot of overlap in groups coming and going. The result was a high level of informal communication among the entire technical staff. A new idea or interesting observation, mentioned casually during the morning coffee break, would be known throughout the R&D organization by noon. At G.E. the cafeterias operated only at meal times. There were coffee and soda vending machines throughout the plant and office areas. The engineers got their refreshments from the machines and returned to their desks to consume them silently. There was practically no inter-cubicle conversation. No doubt the vending machines were a great dollars-and-cents saving over keeping the cafeteria open; but I am convinced that any savings were far outweighed by the loss in informal communication. Another problem with the cubicles was that a talkative co-worker had a captive audience to distract from their work.

Soon after I went to work for G.E. I ran into Dennis Bobka, who had also left Teletype. G.E. at the time had an aging but highly regarded data communications processor, the Datanet-30. Dennis worked in a data communications group, where his expertise with Teletype’s customer applications was quite valuable. Later I think he went across town to work for Motorola.

G.E. at the time seemed to have the best knowledge in the industry of data communication and data flow in the enterprise. Perhaps this was one area where the high status of management was a help rather than a hindrance; professional managers knew what they wanted from a data system. IBM, it seemed to me, had a much too computer-centric view of the world. They regarded a terminal keyboard as a particularly unruly species of card reader.

Labor relations at G.E. were strange. The computer department in Phoenix was a non-union plant. Phoenix natives tended to be anti-union. Arizona is one of the sparsely-populated not-very-industrial states. The natives tended to think of unions as those things they have back East in the steel mills, and in New York City where graft and corruption are endemic, and in California where the union workers are all communists. They preferred for themselves the Western lone cowboy ethos, and voted for Barry Goldwater. Other G.E. workers had come to Phoenix from G.E. plants elsewhere in the country, and were generally fed up with all of the petty nonsense that the unions there habitually engaged in. One of my fellow workers, a technician from Canada who was something of a conservative provocateur anyway, told of a trip he had made to see about something at a G.E. plant in Syracuse. Within fifteen minutes of his arrival he had been the cause of a union grievance. Whatever he was going to do required an oscilloscope. As there was not one in the room he walked across the hall and found one not in use and rolled it to where he needed it. The union contract required that only union technicians move test equipment between rooms.

Still it seemed that the G.E. management in Phoenix did not appreciate the anti-union sentiment in the plant, nor attempt to foster good labor-management relations. Perhaps the management training was geared toward dealing with the militant unions militantly, and didn’t allow for the possibility of a labor force willing to cooperate with management. Or perhaps it was that in the absence of a union management couldn’t figure out a mechanism for two-way communication with the labor force, there being no persons formally designated to represent the workers in dealing with management. Whatever the reason, time after time management made arbitrary, unilateral decisions with no apparent concern for the feelings of the workers. Each time I was surprised that the workers did not flock to the representatives of the big electrical unions, who were always hovering around, and demand union representation.

Another personnel phenomenon at G.E. was that the first-level managers of engineers were extremely retentive of their employees. If some other manager wanted you to work for his unit, and if you wanted to do so, it was practically impossible to get your own manager to let you go. It was said, and perhaps not jokingly, that it was easier to quit and get rehired than to get a transfer from one unit to another. I didn’t try it.

My first engineering assignment at G.E. sounds like a half-day Teletype project: design a transmitting distributor to send several characters of ASCII to aModel 35. It took several months to complete. First I had to learn the G.E. logic circuit set. This was a bit strange. There were logic-level circuits like NANDs and flipflops. Then there were pulse circuits using blocking oscillators and pulse transformers. To trigger flipflops one had to use these pulse circuits; it was not permitted to use the edge of a level pulse to trigger flipflops. So my initial design was turned down by the more senior engineer in the cubicle, although it probably would have worked just fine. After getting a satisfactory logic design I had to go through design automation. Everything possible was wired by automatic Gardner-Denver machines; so it was necessary to put logic diagram information into a form that could be processed through several stages and eventually produce a deck of cards for the wiring machine. I was somewhat familiar with IBMs design automation, which allowed for logic signal names long enough to be self-explanatory. The G.E. system then in use allowed only ten characters for the logic name, and then required a four-character suffix composed according to some arcane rules that I never fully understood. I screamed that this was intolerable. It turned out that there was a new system then under development that would allow considerably longer logic names. Our cubicle had the opportunity to be the first to use the new system, so we decided to do it.

My circuit was to be a part of a larger item; and G.E. didn’t have the ability to make small assemblies. So all three of us in the cubicle had to complete the design of the entire item before we could send our design through design automation and get something wired. That is what took several months, as other sections of the assembly needed special parts that had to be built to order. Then we had to figure out how to mount them and wire them and get them connected to the logic chassis. It made me a bit nervous, since at Teletype we designed things and had them wired up and then expected to do a certain amount of design revision in the lab before arriving at the final design. It wouldn’t be impossible to revise my design under the G.E. system; but it was an awfully long time between design and the first test. G.E. had a unit called QRM, for Quick Reaction Manufacturing[55] which built the first model of anything new. Whereas Teletype would specify every screw and lockwasher by part number, G.E. had a general specification for mechanical assembly. QRM would choose all the bolts and nuts accordingly. Also it fell to QRM to design wire and cable routing; logic design engineers never concerned themselves with such matters.

I ran into the TRAC computer language again at G.E. There was a man who had programmed a TRAC interpreter on the Datanet-30. Later he quit to form a company that was going to do business data processing using software written in TRAC. I never heard any more about him.

Also running on the Datanet-30 was a text editing and formatting system, what we would later call word processing. I used this quite a bit, both for my writing for work and for a project I was doing at home, building a computer with the involvement of some high school students. There was an IBM 1050 set used as a terminal, and later some IBM 2741 terminals. For the high school project I would have the machine type on Ditto masters so I could run off copies for all the students. At Teletype we had talked about some needs for single sheet insertion; the IBM terminals made that easy since they were basically Selectric typewriters. Their reliability left much to be desired.

The Datanet 30 by this time was quite an old machine built with the old slow transistors. We had a joke about that. There was one backpanel wire in the machine something like 15 feet long. We joked that we would soon have to quit making the machines because we could no longer get transistors bad enough (slow enough) to tolerate that kind of backpanel wire length.

An interesting feature of the Datanet 30 was that the software was loaded from paper tape. The entire program was short enough to fit on a loop of tape that ran around on some rollers inside the front door of the machine. The machine had a watchdog timer that would expire unless the software frequently executed an instruction to restart it. If the watchdog timer expired the machine would automatically reload its software from the paper tape.

I’ll include a story about G.E. magnetic tape drives, just because it is funny. IBM and everybody else in the industry made tape drives with vacuum column buffers so the tape could be accelerated very rapidly at the heads in spite of the inertia of the reels. G.E. had bought the rights to a patent for a different buffer technology, using scramble bins rather similar to the bins Teletype used on RT stands to store paper tape. The amount of tape in a bin could be measured approximately by shining lights at the edges and measuring the light striking solar cells at the back of the bins. I’m not sure why G.E. did this; perhaps to get around IBMs patent on the vacuum columns. The scramble bins were much smaller than vacuum columns, but the tape drives as a whole were as large as vacuum column drives. This worked just fine mechanically; the tape could be accelerated rapidly and the servo system usually kept the right amount of tape in the bins. What nobody had thought of was that the tape in the bins rubs against itself, surface to surface. This continual rubbing tends to demagnetize the tape; so we had the phenomenon that a freshly written tape could be read easily, but as the tape was read repeatedly the recording would deteriorate until it could no longer be read successfully. G.E. eventually had to replace all of those tape drives in the field, at great expense.

I remember a visit by Ernie Kettnich and somebody else fromTeletype. Maybe they were trying to sell G.E. on theModel 37. G.E. used IBM Selectric typewriters as console terminals on the computers and had reliability problems with them. I guess with the fairly low volume of computer sales, and only needing one console terminal per computer, it was considered too expensive to redesign the console to accomodate a different kind of terminal. I’m pretty sure I remember seeing a G.E. video terminal with a Model 33 keyboard; but I don’t know if it was a production item or a laboratory prototype.

Although I had seen integrated circuits before leaving Teletype, the G.E. equipment I worked on was still discrete component technology. We did build a couple of integrated circuit modification kits for one of the computer models. It was fortunate that the machines in question used NPN silicon transistors, so we could connect directly to integrated circuits and intermix them with the rest of the logic. G.E. went through a tortuous process of evaluating competing integrated circuits and managed to standardize on the wrong family: the SUHL line made by Sylvania and Raytheon. Soon those companies dropped out of the I.C. business while Texas Instruments dominated.

At the time there were some fairly cheap plastic cased Motorola RTL integrated circuits on the market. I could afford enough of these to undertake a project I had been wanting to do for some time. Back in the ’50s I realized that synchronous transmission offered advantages over start-stop for radioteletype operation. The worst thing about start-stop on the radio is that with a mechanical selector a mutilated stop pulse allows the receiving shaft to keep going around, without latching up the clutch. Typically several characters are printed in error before the shaft gets back to where it is ready to stop for the stop pulse. I have seen a figure that this problem costs something like 15db of signal/noise ratio in character error rate versus bit error rate. With synchronous transmission there is the problem of remaining in synchronism, but not this problem that one bad bit causes several character errors. The second advantage of synchronous operation is that the detector knows where the bit boundaries are. Hence it can accumulate all the energy in a signal pulse, rather than point selecting in the middle of the pulse as a Teletype selector does. Frank Biggam and I had talked about this in connection with the multiplex equipment, it being synchronous. We couldn’t do anything about it because we were being handed a signal that had already gone through a detector; to take advantage of it we would have had to build the FSK or PSK demodulator into the multiplex equipment. Collins Radio had a frequency division multiplex product, Kineplex, which did take advantage of synchronous detection. Teletype had made, in AN/FGC-5 days, a thing called a monoplex. It used multiplex parts to achieve a single-channel synchronous transmission. I never found any detailed information about how well it had worked in comparison with startstop. At the time I didn’t realize it had become a product; but Bob Reek tells me it was used for DEW Line communication over scatter circuits. I believe he said it was sufficiently promising that a synchronous two-channel multiplex was also operable over those circuits.

Thus I had long wanted to try synchronous radioteletype transmission in ham radio, but could not before then because I would have had to build a lot of equipment and the FCC rules required start-stop transmission anyway. After a while (OK, I admit I can be pretty slow sometimes) I realized that it would be possible to transmit a synchronous signal compatible with a start-stop receiver. It was just a matter of sending 7.0 unit or 7.5 unit code at an absolutely regular rate, putting in an idle character if there was no message character available for transmission. 7.0 unit code at 45 baud can be received without difficulty on a mechanical teleprinter and is easy to send synchronously and is fast enough to stay ahead of the keyboard or tape reader. Now with cheap integrated circuits I could easily build a start-stop receiving distributor feeding into a synchronous transmitting distributor. I could use blank as an idle character, or LTRS or FIGS as appropriate. At the receiving end a similar circuit could delete the idle characters, just to keep the machine a little quieter. I built the transmitting circuit and it worked fine, except that in those days we didn’t have much in the way of I.C. breadboarding equipment so it was hard to keep wires from falling off. Then when I tried to transmit on the air with it the RF ran all through the circuit and paralyzed the logic. These problems could have been solved, but I put the project aside as I was doing other things at the time.

I learned a lot about computers at G.E. but I was never very happy working there. I just didn’t have any confidence that the management was leading us in a direction that would be successful. A good telling of the misadventures of G.E. in the computer business is now available in a book, “King of the Seven Dwarfs” by Homer Oldfield, published by IEEE Computer Society. I decided that if I worked there for two years I would feel that I had paid my dues to the company for hiring me and moving me there and could leave in good conscience. I was also starting to think about a non-industry job where I could perhaps pursue some of my own ideas about computer design without the constraints of an existing product line. I made an interview trip to the San Francisco Bay Area, getting in a visit with Bob Weitbrecht in the process. I decided to call someone at Stanford University to see if there was any work there. Whomever I wanted to talk to wasn’t in, so I decided to try Harry Huskey at Berkeley. I knew Huskey only by reputation; he had been in the computer industry since ENIAC, had worked in England for a time, had built the SWAC computer at UCLA, and then headed Project Genie at Berkeley, which was sort of aWest Coast version of Project Mac at MIT. He was also editor of the IEEE Computer Group publications.

My call to Berkeley revealed that Dr. Huskey was no longer there; he had moved to a new U.C. campus in Santa Cruz. I didn’t know such a campus existed; but it sounded like a nicer environment than Berkeley for all the latter’s eminence. I reached him by phone at Santa Cruz; he told me that they were just getting started there and didn’t have any work for an engineer right then, but to call him back in a few months to see how things were coming along. I returned to Phoenix and waited a few months. One day I had a particularly disgusting morning at G.E. and went home at lunch time and called Dr. Huskey. He said he was ready to hire someone, and that he had to make a trip to San Diego and could go by way of Phoenix and meet me at the airport for an interview. This must have gone well, as he offered me a job a few days later and I accepted. This was in the fall of 1968.

During the last week I worked at G.E. I was shown a prototype of a new product, the Termi-Net 300 terminal. This was not a Phoenix production; it came out of a communication products department in Virginia. It was a beautiful machine, a little larger and lower than a typewriter. The printing principle was a rubber belt carrying metal type fingers, each with a piece of type on the free end. There was a hammer for each print position. Thus it was the same in principle as the IBM 1403 line printer. No doubt there was a lot of electronics to make it work. They told me the production models would be made with CMOS and that it would all go onto a surprisingly small number of chips. The keyboard used some magnetic principle and had a very light touch. The speed was 30 characters per second. Mentally comparing this with the Model 37 I had thoughts similar to the infamous proclamation of Lincoln Steffens: “I have seen the future, and it works.” A few years later there would be a 120 character-per-second version. It was pretty amazing to me that a company like G.E. could and would produce such an innovative product. There was nothing else in the entire company’s product line quite like it, so far as I know. The company had no presence at all in office machines. I’m not aware that in Phoenix there had been any discussion of CMOS and the ability to make large custom integrated circuits. After the Termi-Net 1200 G.E. apparently lost interest in making terminals. By then there were several companies making daisywheel printers for formed-character printing and others making dot-matrix printers.

## Back to the halls of ivy (a little) and concrete (a lot)

I arrived in Santa Cruz near the end of September 1968. Dr. Huskey had a couple of barns on his property, so I had a place to store all my stuff while looking for a place to live. I moved in temporarily with Bob Weitbrecht; his home was about an hour’s drive from the Santa Cruz campus.

The faculty of Information and Computer Science (I & CS) was headed by David Huffman, of Huffman coding and sequential circuit synthesis fame, who had come from MIT. The other faculty members were Dr. Huskey, who worked half time for the computer center and half time as a faculty member; and Bill McKeeman, who had just come from Stanford. Bill had given a talk at a recent joint computer conference which impressed us mightily at G.E. when we read it in the proceedings. I&CS was to have been the first board of studies in a new school of engineering at UCSC. Then a high-level committee declared there were already enough engineering schools in that part of the state and that it was not a good time to start a new one. This was something of a disappointment for me, as I had wanted to pursue graduate study in engineering. I&CS remained as a viable program under the Division of Natural Sciences. I met the man who had been hired to head the engineering school shortly before he left.

I will have to leave out most of what happened in the next 30 years to confine the story to matters relevant to Teletype. When I got there the computer center had just moved into its new building. There was an IBM System/360 Model 40 computer and an IBM 1130 minicomputer. Attached to the 1130 was a box made by Western Telematic to provide data communication facilities. There were five Model 33 machines. The business manager was about to contract with Western Union for maintenance on the Model 33s. I told him we didn’t need a contract at that time, that the machines wouldn’t need any maintenance until they were being used, and that I could probably fix most problems as they arose. There were some administrators who wanted to develop remote terminal applications using the 1130 and theModel 33s. They were not working with the 360-40 machine because data communication products for the 360 line were very much more costly than the Western Telematic box. Also our 360-40 had far too little memory to do more than basic things. The state of IBMs operating system technology was far behind what I had seen at G.E.

Nothing ever came of this because Western Telematic considered their design proprietary and would not release programming details. Instead they supplied decks of cards with Fortran-callable routines for use with their box. Fortran was hardly a suitable language for writing an administrative system; but then the 1130 was hardly a suitable machine for running it either. We sent theWestern Telematic box back to the vendor and put theModel 33s aside for future use. The 1130 came with a connection for customer-added devices. I and some students designed a number of things to use with it. One of these, several years down the road, was a synchronous communications port, allowing the 1130 to be used as a remote job entry terminal. The astronomers in particular needed a lot of computing power, and would send their work through the 360/91 at UCLA. The 1130 had a line printer, the same clunky mechanism that IBM had supplied with the 704. Upon opening the modern cabinet you could see the 50s style 407 accounting machine parts which made up the printer mechanism.

When I arrived there was also the wreckage of a Univac Solid State computer that some company had donated. I found that it had been cannibalized of enough expensive parts to be beyond economical repair. Also the punched card peripherals used the Univac 90-column punching rather than the IBM 80-column format. We sent some parts of the Univac to a computer club at the Berkeley campus, where they had one of the machines and eventually got it to run.

Allstate Insurance donated a totally obsolete vacuum-tube Burroughs computer. I guess our main motivation for accepting it was to have it occupy floor space that we wanted to get while the getting was good. I did put it together and we could run it for a little while at a time before it got too hot. The building air conditioning was inadequate for such a computer. When we eventually scrapped the Burroughs I saved the console printer, which was a Model 28 RO. It had a screwy typebox arrangement such that data from the computer did not have to be converted to Baudot code.

There was also a Model 35 KSR and an acoustic coupler modem that had been designed by a Berkeley student and beautifully made on that campus. We could use it to connect to the Project Genie time sharing system at Berkeley.

The Social Sciences people had a statistical lab, containing various mechanical desk calculators and IBM punched card equipment. There was also a Mathatron, one of the early programmable electronic desk calculators. It was about the size of a desk, and had a Model 33 ASR in the middle. The users had written various statistical analysis programs, which were stored in pieces of paper tape. At one point they were about to buy a second Mathatron. About that time Digital Equipment Corp. came to us with a five-terminal timesharing system running on a PDP-8 minicomputer. Dr. Huskey persuaded the Social Sciences people to contribute their Mathatron money and he put in some computer center money to buy the DEC system. We would put two terminals in the statistical lab, two in the computer center, and then there was the console terminal that would also be in the computer center. We used four of the 33 KSRs in this service. The machine had a tiny disk; so we promised some sort of tape storage for users’ programs. By this time we had hired Larry Laitinen, who had just got out of the Army and was a friend of Bob Weitbrecht, as our technician. Larry designed and built a 1200 baud modem, which we used with a cassette tape recorder so that users could record their programs and data. I don’t remember the details anymore, but there was something to do with telephone repeating coils and a simplex circuit. This might have had to do with switching the DEC terminal hardware between 110 and 1200 baud. For some reason the computer didn’t store its own software on the disk. Whenever the power went off, which was pretty often, we had to reload the software from paper tape at the 33ASR console. This took about two hours.

A couple of years later we replaced the PDP-8 system with one using a PDP-11 and software called RSTS. This would serve something like 32 terminals. At first we used DEC hardware to connect the terminals. This took three printed circuit cards per line with only a current loop interface available. We converted some to use RS-232 signals so we could attach video terminals instead of Teletype 33s. We had bought some Hazeltine 2000 terminals, an early video terminal that used magnetic core memory. Later on I designed some multi-port communication interfaces to replace the DEC hardware, getting 8 ports on one large wire-wrapped circuit board. A problem with the DEC hardware had been frequency drift in the bit rate timers. With the new hardware we used a crystal clock oscillator and simply wired each UART to the clock rate we wanted it to have.

A student had designed a program to work out wire routing so that we could use pre-cut and stripped wire with our wire wrapped boards. His input language, used to get fromschematic diagramto computer input, was excellent. His program left much to be desired, taking far too much running time on the slow 360/40 computer. I wrote a new set of programs, using his input language and doing the process as a series of logical steps, that ran much faster. We built quite a bit of equpment of our own design using integrated circuits and wire-wrapped connections.

One office on the campus had an IBMMagnetic Tape Selectric typewriter with a communication port. This used some odd code and baud rate, but it was eventually supported by RSTS. I was still thinking of word processing on a computer, using this machine as a terminal. The Hazeltine 2000 terminals were typical of video terminals of the period. They offered a block mode, in which the operator could fill in a form on the screen and then transmit the whole screen at once. This was used in some transaction processing systems; but we had no use for it and ran the terminals in ordinary full duplex. It was several years later that Lear-Siegler made their famous “dumb” terminal that did nothing but send and receive, letting the computer do all the hard work.

We ran RS-232 signal levels for long distances, perhaps a couple of miles, without modems or line drivers, at speeds of 2400 baud. I also built a multiple current loop to RS-232 converter box to drive a bunch of Model 33s using current loop. This was simpler than putting an RS-232 converter into each machine, as it needed only one power supply.

We had a couple of modems on the PDP-11, used by the local junior college to dial in. Also I used a Model 35 and acoustic coupler modem so I could work on things from my home, about 10 miles from the campus. Quite often when there was a problem I could deal with it remotely and not have to make a special trip to the campus. I had a dog, a malamute. Something about the tones from the acoustic coupler got into her head and motivated her to “talk” quite loudly, which made a mess of the data going to the computer.

There was the change from 1961 ASCII to 1968 ASCII. Some computer languages used characters in ’61 ASCII such as up arrow and left arrow. These characters disappeared from ’68 ASCII. We worked with Fred Mocking, who by now was in Sales at Teletype, on a type cylinder that would compromise the changing characters so that the meanings of ’61 ASCII were not totally lost. The underscore character was made rather wedge-shaped so it could also serve as a left arrow. I no longer remember the other changes.

Beginning while I was still in Phoenix I got involved in Air Force Reserve work, including a summer training assignment. I was assigned to the rocket sled track at Holloman AFB, New Mexico. When I got there they said they didn’t have anything for me to do, and sent me over to the computer center. They didn’t have much for me to do either; so I basically watched the operation and found out what people did and wrote some recommendations, somewhat as a management consultant would do. There was a good group of people, some experienced civilians and some less experienced but quite sharp service men. The computer was a Control Data 3600, which by then was obsolescent. Working in the same building were some German engineers who had been brought to New Mexico along with captured V-2 rockets at the end ofWW-II and for some reason had stayed on there.

Another summer I requested and got an assignment to the Air Force Communications Computer Programming Center at Tinker AFB, Oklahoma. This is where the programming for AUTODIN was done, as well as programming for some other computer-based communication systems. There were some Univac 494 (?) machines that I believe were used in a weather data switching system.

They had a project for me to do. Honeywell had lent them a 316 minicomputer with an attached magnetic tape drive, suggesting that they could find some use for it as an AUTODIN terminal or something similar. The tape drive held a few programming utilities, such as an assembler; and there was a Model 33 ASR for I/O. I obtained manuals for a couple of competing machines, Data General’s Nova and Digital’s PDP-11, and wrote some short pieces of program for all three machines. These program pieces did things I assumed would be useful in a communications application, things like moving a string of characters from one place in memory to another possibly overlapping place, and translating from one code to another. The PDP-11 turned out to be superior to the other machines in these operations, requiring substantially fewer instruction executions to accomplish a given task. I got to visit the AUTODIN switching center. The original RCA computers had been replaced by more modern ones, also made by RCA. I believe by this time the stations were using Univac 1004 machines with drum printers rather than Teletype equipment for printing messages.

After that summer the Air Force had no further use for me and discharged me.

In the early days at UCSC there was an elaborate system for distributing audio lesson material, called Chester Dialog. Students at remote stations could dial up particular lesson material, which was then copied to a reel-to-reel tape deck which was under the student’s control. There was a lot of wired logic and a Siemens T-100 teleprinter for logging its operations. When this system was dismantled a number of years later[56] I acquired the Siemens machine through the campus surplus store. It is one of the European-style Telex ASR sets.

Dr. Huskey got funding from National Science Foundation to work on a minicomputer time sharing system with graphics. There was a company named Data Disc producing a head-per-track disk that could store on each track enough dots to make up a television image. The plan was to use such a disk to store all the bits for a video display. At the time this was about the cheapest way to store that many bits; semiconductor memory was just coming into use and was not yet large enough to store a whole screen of pixels. The disk store could operate either in a character mode, where it generated dot matrix characters, or in a bit mapped mode where it generated arbitrary bit patterns. We acquired a Varian minicomputer for the project. I sketched out, and Richard Cutts designed, a multi-terminal controller for this machine. I still think it was rather clever. This was before UARTs became available. We used separate Teletype-size circuit cards for input and output. The main idea was that you could get an 8-bit shift register chip, serial-in, serial-out, in a 14 pin package. So we used these things to send and receive serial signals in both directions; slowly to/from the terminals and fast to/from the computer. A board in the computer scanned the line cards looking for an input card with a new character or an output card ready for a new character. When it found one it would interrupt the computer to have the situation handled.

The Varian minicomputer came with a Model 33 ASR as the console device. This ASR had form feed. I had been told that Model 33 by design was never to have had such an optional feature; I guess somebody powerful wanted it.

We bought a G.E. Termi-Net 300 for use as a hardcopy terminal for upper and lower case ASCII. Later we bought a Teletype Inktronic KSR for the same purpose at higher speed. We sent Larry Laitinen to Teletype maintenance school to learn how to maintain the beast. He had to modify the Inktronic, as it was designed for a particular Bell modem that did 1200 baud in one direction and 150 baud in the other; we wanted to keep the baud speed the same in both directions. Later we bought a Model 38, in search of a cheap up/low terminal. Somebody gave us some Univac character-serial printers. These were like a single column slice of a drum printer, having a print wheel and a hammer that were pulled across the paper by a stepping motor. There was a logic board underneath, filled with DTL ICs that were all marked with Univac part numbers rather than the manufacturer’s numbers. When I had to work on these it was rarely much trouble to figure out which commercial DTL chip was actually being used.

Eventually our project was stopped because of a federal budget crunch. I think we were all relieved, because the Data Disc machine was giving us a lot of trouble, as were other aspects of the project. There was a period when Dr. Huskey was in India for a year. He did return to the U.S. briefly to testify in the Sperry vs. Honeywell trial which resulted in Sperry’s patent on ENIAC being invalidated. In his absence the rest of us had carved out a much more ambitious design than we probably ever could have implemented. We made a presentation of our ideas at the 1972 Fall Joint Computer Conference.[57]

One of Dr. Huskey’s creations was what he called a Polish assembler. This wasn’t a particularly apt name for it; but it was an assembly program using single characters as operators, and operands preceding the operators. Other assembler programs of the day were designed along the lines of their mainframe cardoriented counterparts; they had columns for labels and operators and operands and comments, and mnemonic multi-character abbreviations for the operators. The advantage of Polish assembler was the very compact notation. A program written in this notation would load much faster from a Model 33 paper tape reader than would a more conventional program; and of course printing was correspondingly faster. A program written in Polish assembler looked like complete gibberish at first glance, just a page packed with a seemingly random ASCII characters; but once you learned to read it, it was quite clear.

Claude Kagan visited with us for a few days as he was attending some computer conference in the area. He insisted we could put a TRAC interpreter on our minicomputer in a matter of days; and in fact he sat there writing code for a day or two to get us started. We added some functions to it, getting it closer to a complete implementation; but I don’t believe we ever really finished it or got it to do anything useful. I don’t remember now if what we implemented was TRAC or something that Claude called A String Language. The latter was actually TRAC but with the names of the functions all changed. The reason for this was that Calvin Mooers had tradmarked the name TRAC, so nobody could have a TRAC interpreter without paying him a royalty and in return his certifying that what you had was a genuine TRAC interpreter. Changing all the function names resulted in a language that was really TRAC, but presumably did not infringe the trademark and could have fewer or more functions than genuine TRAC possessed. Later on Claude and his group of youngsters, R.E.S.I.S.T.O.R.S., produced a language they called SAM-76, which had all the features of TRAC and a lot more.

Another visitor was Fred Brooks, now most famous as author of “The Mythical Man-Month”. At the time he was a professor of computer science in North Carolina. Previously he had worked for IBM and was a principal architect of System/360. It was hard to imagine that this soft-spoken professor was the man who sat across the desk from Thomas J. Watson, Jr. and told him they were ready to bet the company’s future on a new architecture.[58]

At one point Computer Science got a new permanent home in a new building. I was in charge of ordering lab equipment and arranging the space. I asked for movable interior walls such as we had had at Teletype. The construction people turned this down, saying it was much too costly and they could build metal stud and sheetrock walls anytime we wanted them for less money. I wished later I had been more persistent, or had got some powerful faculty members in favor of the movable walls. It turned out to take an act of the state legislature to get money to rearrange the interior of a building; and the process literally took years. 58Fortune magazine, September and October 1966 issues, tells the story of System/360 and the various personalities involved.

On the Computer Center side of the street, we eventually switched from RSTS to Unix, and grew from one PDP-11 to about fourteen VAX machines. With Unix we had to quit using Model 33s and our old CRT terminals, as Unix demands up/low case capability. We bought CRT terminals from a variety of vendors. The first one from Teletype that we looked at had a rather bad keyboard. It was an electronic keyboard, not the horrid Model 37/38 thing, but keys tended to jam if they were not hit right in the centers. There was a later Teletype effort that was a pretty satisfactory terminal; but we didn’t buy any. By then there were so many manufacturers of video terminals that Teletype didn’t get anyone’s attention. On a visit to Berkeley I saw one of the AT&T-style graphics terminals. Bell Labs seemed to be pushing the concept of a time-shared computer driving a graphics-capable terminal, ignoring the more likely future of graphic computing workstations.

We did buy a few Model 43s as hardcopy terminals. We also bought a number of Model 40 printers, the OEMmodels with the not-exactly-RS-232 interface. We ran these at 2400 baud. The printer had a ready-for-next-character signal. This would have worked fine with a microcomputer that could stall until the printer was ready to proceed. It didn’t work so well with the timesharing system; but I was able to write a Unix driver that would send idle characters when the printer was not ready. We ran the Model 40 printers for as long as we could get maintenance on them. However they were used less and less as laser printers with PostScript came into wide use. With all these printers the concept was to have a single printer serving a room full of video terminals. The time sharing users simply had the computer direct their print jobs to the nearest printer. Because there were several separate time-shared minicomputers I designed a printer-sharer circuit that let the computers compete for access to a printer and granted access to only one at a time. Later there was networking software that allowed a single computer to drive all the printers and any other computer to send jobs through it.

The mainframe IBM-style computer had a big Xerox high-capacity laser printer. Time-sharing users could also send print jobs through this printer. During this same time period a number of offices on the campus acquired what were then modern character printers: Diablo and Qume daisy wheels and NEC Spinwriters. Soon after the introduction of daisy wheel printers the typewriter industry switched to this technology. I bought a wheel typewriter at Sears that had a computer printer interface built into it.

At one time we requested information from a number of computer vendors about their offerings for large-capacity time sharing systems. We asked for some of the things we were already getting from our PDP-11s: terminal ports at 2400 baud and automatic restart following power failures, among others. I got a call from a supposed data communications expert at IBM who couldn’t understand how we operated async terminals at 2400 baud - he seemed to be mentally blinded by the modems available at the time, which were limited to 1200 baud async and 2400 baud synchronous. Univac told us that each async port would cost \$11,000. Most of the large computers required a card reader to get started up, even if we didn’t plan to use any card input in normal operation. Most of the vendors could not imagine automatic restart following power failure. We decided to stick with multiple minicomputers, even though those were more difficult to administer than a single large machine would have been.

As the number of computers grew and as the number of terminals grew into the hundreds we acquired a port selector. This was essentially a time-division circuit-switching exchange allowing users to say at the terminal which computer they wished a connection to. At 1200 baud and below it simply sampled the signal several times per bit with no synchronism to the characters; so distortion was high but tolerable. It did however cause havoc with some of our longer RS-232 connections. At 2400 baud and above it used UARTs and switched characters in parallel.

Electrical storms are quite rare in Santa Cruz, so we didn’t often have trouble with the RS-232 connections run in underground cable. On the rare occasions when we did have an electrical storm it would sometimes damage RS-232 drivers and receivers. I remember going to several of the Hazeltine terminals and replacing transistors blown by lightning. Several years later when we had lots of connections and the port selector, a lightning storm caused fires in the port selector. Lightning blew the RS-232 driver chips. The manufacturer had not provided fuses on the 12-volt supplies, so the blown chips shorted positive and negative 12 volts together, causing the chips to burn and burning the circuit board underneath. After that we tried to shut down the port selector whenever there was likely to be a lightning storm, and to ask the users to unplug their terminals. I was surprised that lightning did so much damage to underground cables. We learned later that when the cables were installed the shields had not been bonded together and grounded, so they provided no protection to the circuits inside.

During this period Digital Equipment decided to quit using Model 33 ASR sets and to build their own terminal-type printers. There was the DECWriter I, which was not around for long, and the DECWriter II made in large quantities. These were all dot-matrix machines. Starting with a 30 char/sec floor model they went to a 120 char/sec model, and also a typewriter-like desk model. These machines lacked paper tape capability; but by then most customers were buying some faster kind of I/O medium anyway. Data General may have also made a hardcopy terminal of their own, following the lead of Digital.

After building up to hundreds of mostly CRT terminals and expanding the port selector to a large size we started switching to microcomputers and Ethernet. By the time I retired we had got rid of the port selector and operated the modems and a few RS-232 terminals using Ethernet terminal servers. There seemed to be no limit to the demand for modems. Students and faculty have personal computers at home, but they want to send and receive e-mail through the campus server and do other things that require connection to the campus network. We got into a relationship withMetricom, an early maker of wireless network modems and provider of Internet service through their network. Then we got a service in which Pacific Bell provided modems and connected to our network. Students had to pay a fee for using these instead of the free ones we continued to provide; but they could usually get connected via Pac Bell when all of our modems were busy, which was most of the time. The nature of using modems has shifted over the years, from terminals to microcomputers emulating terminals to microcomputers running Internet TCP/IP protocols. This of course correlates with the increasing speeds of modems. It would be practically unthinkable to run Internet Protocol over a 300 baud connection; but at 14 K baud or higher it becomes quite reasonable. There was a communication satellite out over the Pacific which NASA had quit using and made available to Pacific Rim nations for educational purposes. UCSC had one of the terminals. I was asked to advise how they might transmit Teletype signals using this satellite. I recommended basic amateur radio technology, using audio tones into the voice channel. Some other people in the operation felt they should be using Model 33 equipment and ASCII; maybe they wanted to be able to exchange computer programs. I was inclined to suggest they look for Baudot equipment. There must have been a lot of it scattered over the Pacific after World War II and Korea; and I had a hard time imagining how Model 33s would get the maintenance they needed out in the Pacific island nations. I don’t know if anything was ever done one way or another.

During my early years at Santa Cruz there came to be more Model 28 equipment in the hands of radio amateurs. I suppose this resulted from conversion of TWX from Baudot to ASCII and from similar conversions in other teletypewriter services. There was a project among some of us to optimize a Model 28 printer for amateur radio. Amateur radioteletype is characterized by a frequently high error rate; the emphasis is on carrying on a conversation with a friend, or contacting a rare station in some distant part of the world, rather than on getting perfect copy. One part of the optimization was to install the automatic carriage return and line feed set of parts, so that a missed carriage return would not result in a black square at the right margin of the paper. Then we had the carriage return actuate the line feed function, to prevent a missed line feed from causing an overstruck line. There was at the time some problem with pranksters who would start up an unattended printer and send it nothing but line feeds, so that all the paper supply was unrolled. This was foiled by making linefeed a once-only function.

In those years TTL integrated circuits dropped steeply in price. I was able to build a speed converter out of TTL, and then a re-creation of the compatible synchronous transmitter I had experimented with in Phoenix. Another ham was going to build a receiver to take advantage of the synchronous signals. I don’t remember that he ever completed it, but he told me recently that he had done so and was able to lock to the bit and character rates. Independent of that effort, some other types of frequency shift converters benefited from simply having transitions going on all the time, rather than sometimes long pauses between hand-sent characters. The concept became known as “diddle” and was built in to many of the later generation all-electronic radioteletype terminals.

Amateur radioteletype and other digital amateurmodes of course have changed greatly along with the changes in commercial communication equipment and techniques. An early design was an integrated circuit speed converter and first-in, first-out buffer. This allowed one to run the teleprinter at 100 wpm while transmitting and receiving 60 wpm. The FCC rules were relaxed to allow speeds up to 100 wpm and ASCII in addition to 60 wpm Baudot. There was very little use of these expanded privileges in practice. At 100 wpm the signal pulses are shorter than at 60; and using ASCII they are shorter yet. Shorter pulses imply wider receiver bandwidth, and hence poorer signal to noise ratio. Shorter pulses are also more adversely affected by multipath radio propagation, which is often a problem even at 60 wpm. So 60 wpm Baudot continues in use to this day, to the practical exclusion of higher speed Baudot or ASCII.

A few Baudot-only or Baudot plus ASCII video terminals were produced. The small demand made for small production and high prices. With the coming of microprocessors there came to be a new class of amateur products for connection to an ordinary ASCII terminal. These provided for several modes of operation such as Baudot, ASCII, packet, and AMTOR. AMTOR is an ARQ system for amateur use, similar to SITOR used in the marine services. It transmits short blocks of characters in a four-out-of-seven code and then listens for an acknowledgment character before proceeding. Packet operation uses a protocol similar to the X.25 standard, or the Internet Protocol. These microcomputer products are relatively inexpensive as most of the program is stored in read-only memory and there are no moving parts.

With the coming of personal computers (and even prior to the IBM personal computer) there came to be software to run on these machines for amateur radio use. Some programs simply provide a Baudot terminal, perhaps with extra features such as selective calling and the ability to send canned messages and store sent and received text on disk. Other programs are a replacement for the ASCII terminal in connection with one of the specialized microcomputer boxes. These provide an easier to use operator display and add features such as messages storage and log keeping.

There also came to be boards designed to plug in to popular personal computers. Some of these perform functions similar to the stand-alone microprocessor boxes at reduced cost by using the computer for power supply and for storing the software. Others are digital signal processing engines. One class of these does FSK demodulation for Baudot, ASCII, AMTOR, and Pactor (a protocol similar to AMTOR) as well as a more complex modem for Clover, a four-tone modulation scheme that adapts to changing channel conditions.

The latest development came with the arrival of the 486 and then the Pentium processors. These processors are fast enough to do digital signal processing right in the computer itself. The widely-used computer sound cards provide the analog-to-digital and digital-to-analog conversion. Thus the PC has become a modem and user interface all in one, requiring only a connection to a radio set to become a communication terminal. The currently available modes include:

• Baudot, at many different speeds and frequency shifts
• Phase shift keying at 31 baud, translating the ASCII character set into something like Huffman code so the more frequently used characters require fewer bits to transmit. Also phase shift keying at higher rates
• Hellschreiber, using on/off, frequency shift, or phase shift keying. This is an electronic simulation of the 1930s-era teleprinter system invented by Rudolf Hell (and duplicated by Teletype with the Model 17).
• Multi-tone frequency shift keying, using 4-32 tones and approximately one tone per character transmitted. This allows the signal pulses to be much longer than in regular Baudot, and hence has great immunity to multipath distortion.
• A very robust modulation scheme involving 63 simultaneous carriers and elaborate forward error correction
• An automatic link establishment system compatible to some extent with those used by the military and civil government agencies. These systems hop around among several frequency bands, sending test packets and choosing the best frequency for traffic.

In addition to these a ham has developed a digital FSK modem that accomplishes compatible synchronous transmission and reception of Baudot. Although the improvement over asynchronous DSP Baudot is slight, it tickles me that now somebody has accomplished rather easily the thing I wanted to do so many years ago when it was so hard to accomplish. At my request he added a cleaned-up Baudot signal output to the RS-232 port so I can drive a mechanical teleprinter.

A few years ago I was promoting an amateur radio annual event, “Green Key Night.” This took place on February 20, the anniversary of the first FSK contacts on amateur radio on the HF bands in 1953.[59] On that day amateurs were encouraged to get on the air using mechanical teleprinters if they can, using wide (850-Hz) shift if they can, using vacuum tube radio equipment if they can, but in any case to remember the pioneers and wallow in nostalgia and have fun. After a few years with hardly any participation I gave up on it. There does seem to be a small resurgence of interest in operating mechanical teleprinters. One still sees advertisements, “Model 19 going to the dump, unless someone takes it”, but there are starting to be advertisements offering homes for the old machines.[60]

I retired from the University early in 1998 and moved back to Arkansas.

## Some afterthoughts

I do not blame Teletype management for the demise of the company. Many other old and well-managed companies have fallen by the wayside in recent years; and even mighty IBM has seen some very painful times. As a subsidiary of a subsidiary of a drastically restructured AT&T, Teletype could have had the plug pulled at any time by one of the parent companies in spite of what its own management could do. After the Bell System breakup AT&T seems to have had a lot of trouble deciding what business it wanted to be in, and the same can be said for Lucent, the former Western Electric.

It seems to me that the downfall of Teletype resulted from a combination of several factors.

• Unprecedented progress inmicroelectronics caused Teletype’s store of knowledge and its manufacturing capability to depreciate to no value practically overnight. New companies sprang up like weeds as it became possible to create a variety of new products just by putting together parts bought from the semiconductor makers.
• Teletype’s great factory may have bred a certain weakness; when you can make anything at all you may make too many different things. (Consider the number of part numbers dedicated to screws and springs, for instance.)
• A whole series of changes, some technological and some political and legal, rocked the familiar business environment. This began with Dataphone and the use of the switched voice network for data transmission. It continued through the CarterFone decision, the Bell System breakup, and further deregulation of the communications industry. The historic scarcity of telecommunication bandwidth gave way to a glut as competing long distance carriers entered the field and as optical fibers replaced copper cable and microwaves. Western Union, which had seemed in the early 1960s to have a rosy future, totally collapsed. Microcomputers largely replaced simpler equipment used as communication terminals.
• A lack of competition for so many years led to a certain amount of stodginess and complacency, and retarded development of a market-driven corporate culture.
• The 1956 consent decree seems to have marginalized Bell System participation in the world of business data communication, as communication became subsidiary to data processing.
• Increased participation in the market by foreign companies, and increased use of offshore production by domestic firms were probably factors as well.

I have learned that Teletype developed a remarkable capability in-house to produce large-scale integrated circuits.[61] Such a capability gives a company an advantage over competitors who have to work with off-the-shelf parts; yet it is tremendously costly to maintain and perhaps was not in the company’s strategic best interest.

I like to use the demolition of the Touhy Avenue complex and its replacement by a shopping center as a metaphor for what is happening to our society as a whole: Where once we made things, now we buy things that others have made.

In 1960 the U.S. teleprinter business belonged to Teletype, Kleinschmidt, and Teleprinter Corp. (MITE), the latter two doing business mostly with the military. Western Union had occasionally dabbled with making its own teleprinters and paper tape equpment, and had imported a few European teleprinters to get Telex service started. The telephone companies’ doctrine of “no foreign attachments” was firmly in place. Communication switching, both voice and teleprinter, was almost entirely electromechanical. Teleprinter switching systems used lots of paper tape for intermediate storage. ASCII was still on the horizon. TWX was still manual and Baudot; Telex was just getting started in major U.S. cities. Western Union seemed to have a bright future. Computers were well established in the business world, but there were very few instances of teleprinters (or terminals of any kind) connected to remote computers. Information transmission was via voice-grade lines or telegraph-grade lines limited to about 75 bits per second. There was still a lot of open-wire line in the telephone toll plant.

Although Teletype equipment had improved tremendously over the previous 50 years, in another sense the technology had not changed at all. Products continued to be intricate mechanical assemblies of parts made mostly on punch presses and screw machines. The world was about to turn upside down.

Just when it appeared that telegraphy was on the brink of a steep decline along came on-line computing to create a new need for it. Computer systems needed the kind of input that keyboards could produce and produced the kind of output that teleprinters could easily display. Whether the terminal to computer wiring was local or telegraphic or derived via modems from telephone circuits was immaterial. The boundary between communication and data processing, which had seemed so firm and clear at the time of the 1956 consent decree, began to disappear in the manner of the Cheshire Cat. Electronics came to be the principal underlying technology of both, and began to progress at a rate never before seen.

The voice telephone network approached ever closer to its mature state in which all calls are customer-diallable. Transistorsmade it possible to offer customer premises modems and autodialers for use on the voice network. The Dataphone offerings dramatically modified the doctrine of no foreign attachments. Later the Carterfone decision blew it completely away. Customers were free to obtain their data terminal equipment on the open market. It became possible to implement business data systems using the switched voice network. Previously these would have had to use private line service at much greater cost. Because the switched voice network allowed considerably higher bit rates than were possible with telegraph circuits, customers had an incentive to want high-speed data equipment in preference to slow teleprinters. The Bell System breakup and the demise of Western Union meant that nationwide business firms no longer had a single company to deal with for communication facilities. The mere fact that the voice switched network kept on working was another reason to use it for business data communication.

Cheap fast transistors led to a generation of computer equipment that was cost effective in replacing electromechanical communication switching systems. For message switching purposes computers also had the advantage of being adaptable to customer protocols rather than requiring customers to adapt themselves to the protocols wired into the switching systems. Computer switching in fact arrived just in time to cope with network complexities that were practically beyond the capabilities of electromechanical systems. Computer technology further offered higher reliability and lower maintenance as compared with the electromechanical equipment it replaced. Computers used solely for message switching had a short market life as the business world moved on to systems integrating communication and computer applications.

Following cheap fast transistors came even cheaper and faster integrated circuits, and then microprocessors. Products based on intricate mechanisms became obsolete practically overnight. The aggregate motion stock ticker was Teletype’s last successful product of the old kind; and it had an unusually short product life. Integrated circuits lowered the barriers to entry into the industry. Video data terminals could be home built by hobbyists. Companies producing terminals popped up like mushrooms. Mechanical simplicity was bought at the price of electronic complexity. That complexity ultimately came down to a matter of program instructions, not trivial to produce but not requiring any significant investment in factory machinery. Over and above what it could do offline, the personal computer became the ultimate communication terminal, programmable to meet any imaginable customization.

Printers, magnetic card readers, and other special devices became computer peripherals. Printer technology went through dot matrix and daisywheels to laser and an ink-jet technology having nothing in common with Inktronic. Powerful electronics made facsimile at long last a cheap and practical means of record communication. The new cheapness allowed fax to enter markets that had been closed to TWX and Telex. Personal computers can also function as fax machines and can generate fax images from computer text. The packet-switched Internet became an alternative to modem communication over the voice switched network. As the Internet spread from a few research sites to the whole world personal computers became communication devices in other ways; first electronic mail and news, then pictorial, voice, music, and motion picture communication for the general public. Fiber optic technology turned the scarcity of bandwidth into a glut.

Electronics has always been an unusually flexible technology. Anything from a radio to a computer to a metronome to an aircraft control system could be built up out of more or less off-the-shelf parts put together in almost any convenient physical arrangement. Unlike mechanical technology there was rarely a need for a lot of custom-made parts fitted together precisely in a manner requiring great ingenuity to design.[62] The electronics of 1946 was not so different from the electronics of 1936 except for microwaves and miniaturization. The electronics of 1956 was not so much different either, except that we were pretty sure transistors were going to be important sometime soon. Even by 1966 it was hard to imagine that parts produced in semiconductor furnaces could ever compete with those produced on punch presses. How could we then have imagined a 104-key electronic keyboard selling at retail for ten dollars?

It’s hard for me to imagine what Teletype might be today if it had survived. A maker of printers, competing with Hewlett-Packard, Epson, Canon, and Lexmark? Enlarge that group to include the makers of office copiers, since today’s models seem to be based on scanning and electronic printing, rather than direct copying. A maker of personal computers, competing with Hewlett-Packard, Dell, Apple, and a few others? A maker of handheld terminals with many capabilities, competing with Apple, RIM, Nokia, Motorola, and others? A maker of point-of-sale equipment and other non-consumer goods? Perhaps a maker of specialized equipment completely out of the public eye; or perhaps a maker of something totally unrelated to its former products, as with the GPS navigation company currently using the Teletype name.

## References

1. Principles of Electricity Applied to Telephone and Telegraph Work, A.T.&T. Long Lines, 1938 edition
2. June, 1953, page 35
3. The Western Union friend I’m sure would gladly have taught me Morse code, except that his was American Morse, not the International Morse used in radio. He sometimes remarked that he didn’t understand how anybody could copy that gibberish on the radio, not having a sounder to click it out.
4. Pre-electronic, using motor-driven faceplate distributors.
5. I have since learned from an article in Bell Laboratories Record that Model 14 and 15 equipment was operated at 100 WPM during World War II as a war emergency measure. The need to move lots of traffic justified the considerably increased maintenance effort.
6. In another article I suggested that it was the sight of my forlorn 21-A printer in a corner of the lab that prompted the offer of new Teletype equipment. I don’t know whether this actually had anything to do with it, or whether they even saw the 21-A.
7. Connecting two closely-spaced dipole antennas together gives a radiation pattern with lots of peaks and nulls, making it possible to determine the angle of arrival of signals.
8. later, Jordan
9. Bob Reek believes all the production mux systems used the bipolar transistor counters; so the 16-channel mux I saw at Fullerton with point-contact counters may have been a special case. We know that Western Electric was eager to cease production of the 2N110 point-contact transistors.
10. One could argue that Varioplex was the ancestor of packet switching, as it allocated a channel among users by allowing them to send at most a fixed-size packet at a time. I doubt that the inventors of packet switching were even aware of Varioplex.
11. Chuck Winston received several patents relating to constant-current selector magnet drivers; but the circuit embodied in the 182630 circuit card and used in the 32/33/35 models of equipment was patented by R. J. Miller, patent No. 3,293,505, Dec. 20, 1966.
12. Bob Reek had already thought of the low-voltage selector idea; he recently showed me a page from his notebook.
13. Silberg patent No. 3,147,339, Sept. 1, 1964
14. In the mux system the cards were mounted in pull-out drawers fitted into a standard military rack cabinet. The card sockets were wired with formed cables of stranded wire and soldered connections. In the shoe box modules solid conductor wire and wire wrapping were used to interconnect the card sockets.
15. IBM Systems Journal vol. 6 issue 4, 1967, p. 267.
16. Byrnes patent No. 2,927,960, March 8, 1960
17. Zenner patent 3,056,546 issued Oct. 2, 1962. As the patent for the entire machine was filed for in May of 1959 I assume Dr. Carlson was working on some specific problem for which a one-reed punch was sufficient. It may be that I am mistaken and saw this work in 1958.
18. This was several years before the beginning of service on the Skokie Swift extension of the elevated. The tracks later used for the Skokie Swift were at that time used by the old North Shore Line railroad.
19. Led by the late Mike Dertouzos, who went on to head the Laboratory for Computer Science at MIT.
20. I had taken the one computer course offered in Electrical Engineering at the U of A; but we didn’t have a computer there at the time. During my last semester there the Agriculture school acquired a Bendix G-15 computer, which was to be used to breed bulls. I never got to see it.
21. Brodrueck patent No. 3,845,710, Nov. 5, 1974
22. In fact, IBM had developed automatic machinery for making the transistors. Then IBM management decided they did not want to tie up capital in component manufacturing and sold the whole works to T.I.
23. Only after achieving a profitable business producing modules were the company founders allowed by their financiers to build computers. At the time I first wrote this Digital Equipment was a major computer manufacturer. The company did not succeed in transitioning to personal computers, was acquired by Compaq, and then Compaq was acquired by Hewlett-Packard.
24. It is not clear to me whether the Army system was ever actually deployed.
25. It was always called the Delta system because it was designed for Delta Airlines. Later United Airlines got a similar system. The Delta installation was soon replaced by a computer-based switching system. The United system was removed after the WADS tariff was disapproved.
26. a dry electrosensitive recording paper developed by Western Union. More about this later.
27. Zenner patent No. 3,014,093, Dec. 19, 1961
28. In this case the reason for using tubes rather than transistors was to get a large voltage swing to apply to gates controlling the analog signals.
29. Reszka patent No. 3,191,101, June 22, 1965.
30. ADIS was an acronym for Automatic Data Interchange System, which just happened to be used for what FAA called Service A. Hence Service A:ADIS = Service B:BDIS = Services C and O:CODIS; but BDIS and CODIS are not acronyms.
31. This shows the separation between data processing and data communication, as required by the 1956 consent decree, starting to get fuzzy. Customers were renting private-line Model 35 ASR sets from the telephone companies to use entirely offline as keypunch machines.
32. In Ran Slayton’s museum tour document the Model 29 is identified with an up/low printer intended as a replacement for the Model 20. Such a machine did not sell. It is reasonable to use the same model number for the BCD code machine, since in both cases a six-level code is involved. The machine which many of us knew as the Model 29 was sometimes called the “Model 28 IDP ASR Set”.
33. However, there were special data-only interoffice trunks. The flexibility of #5 crossbar made it possible to route TWX calls over data trunks and voice calls over voice trunks.
34. This system was ancient even then; it is described in the November, 1951 issue of Western Union Technical Review.
35. Patents 3,546,707 3,553,359 3,555,266 and 3,688,032
36. Published as “The Design of Transformer (Diamond Ring) Read-only Stores” in IBM Journal of Research and Development, September 1964, p. 443. This refers to earlier work done at Bell Laboratories.
37. I believe this is W. Y. Lang, author of “Advances in Printing Telegraphy in 1964”, IEEE International Convention Record, Vol. 13 part 1, 1965, and “Advances in Printing Telegraphy in 1965”, IEEE International Convention Record, Vol. 14 part 1, 1966.
38. Probably the same as, or derived from, Halvorsen patent No. 2,625,601, Jan 13, 1953
39. I recently heard an anecdote about a different company and a different product; but it involved a marketing man and an engineering-oriented executive. They argued whether their company needed a good product with excellent marketing or an excellent product with good marketing. This seems applicable to the situation with competing IBM and Teletype products.
40. From looking at a Model 37 parts book recently, it appears that some sort of integrated circuit regenerator was part of the product. I don’t know whether this was used for receiving or for transmitting.
41. Teletype had patented a daisywheel printer in 1938, but without electronics it was not a very promising product. See Reiber patent 2,146,380.
42. However, I have been told that Telex was a big money-maker for Western Union.
43. Government policy over many years seems to have been to keep W.U. with exactly one foot in the grave at all times.
44. Bell System Technical Journal, December, 1970.
45. Probably Scott patent No. 3,217,182.
46. The full story of this work is told in a book, “A Phone of Our Own,” by Harry Lang of Rochester Institute of Technology, published by Gallaudet University Press.
47. Weitbrecht patent No. 3,507,997, April 21, 1970
48. Ran Slayton’s museum tour document mentions a daisywheel printer that Teletype had started to develop.
49. As documented in the book, ”Arthur Collins - Radio Wizard” by Ben W. Stearns. It seems tragic that Art Collins had an excellent vision of the future of computers and communication, but pursued it obsessively at a time when the technology was just not there yet. After reading the book I am really glad I didn’t take the offer of employment at Collins.
50. IBM rushed to produce a similar machine, System/360 Model 67, and promised a MULTICS-like operating system to run on it. The latter was never delivered. Customers ran the machines as Model 65s; or in the case of University of Michigan with an operating system written in-house.
51. MULTICS had a lot of influence on operating system design, but proved to be an evolutionary dead end as a product. It was married to a large, costly mainframe computer. Time sharing systems running on minicomputers soon proved to be more appealing. They were relatively inexpensive to begin with; and a facility could be expanded simply by buying more of them. The UNIX operating system from Bell Labs was practically given away to educational institutions, ran on popular minicomputers, and was considered by many to be superior to computer manufacturers’ own offerings. Then microcomputers took over.
52. I guess there had been a downturn in the local economy that had temporarily derailed some big development plans. When I passed through Phoenix several years later the shopping center had been built; and it was indeed big.
53. However there was a Dr. Potts who had a long inventive career at Teletype; and there had been a Dr. Carlson in Teletype R&D when I worked there in the summer. There seems to be some question whether either of these gentlemen contributed anything worthwhile to the product line.
54. Scott Adams reports that many people see in his Dilbert comic strip a caricature of the companies they work for. For me the pointy-haired manager character seems to have G.E. written all over him.
55. This always amused me, because in amateur radio QRM is the Morse code abbreviation for “I am being interfered with.”
56. The replacement system was simply to make multiple copies of tape cassettes for the students to play on their own machines.
57. "An Eclectic Information Processing System", proc. FJCC, 1972, Part I, p. 473.
58. Fortune magazine, September and October 1966 issues, tells the story of System/360 and the various personalities involved.
59. Prior to that date audio tone FSK was permitted and used on the VHF bands. FSK was permitted only on the former 11-meter band. There was some radioteletype operation on HF using make-and-break keying. Amateurs petitioned the FCC for permission to use FSK on the HF bands. FSK was the norm already for commercial and government HF radioteletype. After about two years of rumination the FCC announced that amateurs could use FSK on the HF bands, with certain restrictions, starting Feb. 20, 1953.
60. An interesting topic for a future paper is that Frequency-Shift Keying seems to have been invented by an engineer at Teletype, Lawrence Schmitt. Experimental radioteletype work was done by Morkrum in the 1920s.
61. Book, ”Teletype, We Made That Data Move!” by Herbert A. Waggener.
62. This point is well illustrated by Teletype’s first electronic multiplex, manufactured by an outside contractor without drawing upon Teletype’s great knowledge bases of mechanisms and metalworking.