CHAPTER 5

Teletypewriter Intercommunication Expands

_TELEX_

As a result of the acquisition of patents of the Morkrum-Kleinschmidt Company by the Lorenz company, Siemens & Halske, and, later, the Creed company in England, all of which we have discussed briefly, teletypewriter intercommunicating expanded rapidly. In just a short time, through the cooperation of these companies, it spread over all of Europe and was named TELEX (_TEL_eprinter _EX_change Service).

Dr. Gerhard Grimsen of the Lorenz company, in a letter to Edward E. Kleinschmidt, dated July 11, 1962, states, in part (slightly edited):

The story of printing telegraph apparatus using an equal length code in the Lorenz Co. commences in 1927 with the acquisition of the most important patents of the Morkrum-Kleinschmidt Co.

Before then, the Lorenz people were busy in manufacturing Morse apparatus and delivering exchange tickers which used the Hughes code. The transmitter had a piano keyboard, the receiver was a page printer with a moving type wheel.... The biggest network of this kind was installed in the Berlin Police service (with one transmitter and about 300 receivers). The connections between the headquarters and the substations were built by using guttapercha cable lines owned by the police administration. This broadcasting network was erected around 1907. By 1927 the cables had aged, by normal corrosion, to such a degree that instead of 110-volt double current transmitting voltage, little by little, up to 220 volts was necessary for a fairly satisfying operation. Also, the maintenance of the apparatus became more costly.

This was the situation when some communication experts of the police and the post administration made the first studies about the newest telegraph technique in the U. S. A.... They found that the start-stop, five-unit tape printer, the Model 14, developed and manufactured by the Morkrum-Kleinschmidt company, would be the best instrument to replace the old ones in the police service as well as in the telegraph business of the German post administration.

Of special importance to the police service was the fact that by introducing this apparatus, it was not necessary to build a new network because now it became possible to rent normal telephone lines using single current, 40-milliampere, 60-volt current only.

Siemens and Halske engineers, in 1925, had designed a teleprinter using the five-unit-code, start-stop principle. This was manufactured and improvements added, including the new start-stop method developed by Morkrum-Kleinschmidt. The Creed company, which had started manufacture of start-stop teleprinters before 1930, having purchased several Morkrum printers before the consolidation of that company with the Kleinschmidt company, also designed a teleprinter for the new five-unit-code, start-stop system.

In another write-up, Dr. Grimsen states that after the Siemens company came into the picture, a fully automatic teleprinter network was started in 1933 with a trial installation between Berlin and Hamburg for about forty private subscribers. The results were so encouraging that the German Reichspost continued the work, and five years later the TELEX system contained about 10,000 subscribers.

TELEX service was introduced in Great Britain in 1932 and was worked over the telephone network, using a single-tone voice frequency carrier signal which was keyed on and off by the teleprinter transmitter. (From Freebody’s _Telegraphy_.)[12]

Interconnection for TELEX service was made by dialing a subscriber as in telephone operation. TELEX directories then, as now, gave the call numbers of subscribers. Types of answerback devices were designed in both England and Germany which finally developed into an arrangement whereby the calling subscriber would, after dialing a number, press a special key, the shifted D key—named the “Who-Are-You?” button—which would cause the transmission of a signal code automatically to activate the called teletypewriter mechanism into transmitting its TELEX number.

Further apparatus, a device to punch the code in a tape and a punched-tape-controlled transmitter, was soon added.

The Siemens company also developed and built completely automatic switching equipment for the TELEX system which is used by many telegraph administrations.

Through the cooperation of the companies who were manufacturing teleprinters and associated equipment, the many problems that appeared were eventually solved to improve the apparatus and bring the TELEX system to eventual perfection for worldwide telegraph communications. (At the time of this writing, according to statistics, there are nearly 1,000,000 TELEX subscribers throughout the world.)

One of the problems faced in setting up such a worldwide system was that of standardizing the code and operating speed. At the time of Kleinschmidt’s stay in London in 1930 to close negotiations with Creed for the sale of Morkrum-Kleinschmidt’s foreign rights, he met Mr. Martin Feuerhahn of the German Telegraph Administration who at that time was in conference with Creed and representatives from the British Telegraph Administration as to standardizing on an alphabet and telegraph code for international communications. Mr. Feuerhahn argued for the adoption of the American Murray alphabet and code, stating that he already had the approval and consent of the French, Italian, and Belgian telegraph administrations.

Mr. Feuerhahn and Kleinschmidt spent some hours together. After their return to their respective countries, Kleinschmidt received a letter from Mr. Feuerhahn referring to their talks and stating that he had been in correspondence with Mr. Benjamin of Western Union and Mr. Parker of Bell Laboratories with regard to code and other pertinent matters of standardization so that an International Teleprinter Exchange could be extended into the United States. Another letter dated October 10, 1931, reviewed the aforementioned standardization search.

The Murray alphabet and 7½-unit code were soon adopted and are still in use today in TELEX.

In later years, an association, the Consultative Committee on International Telegraph (CCIT—now the CCITT to include the telephone), was formed and met regularly to discuss problems and to set operating regulations for the TELEX apparatus in an intercommunicating system. The CCITT at this writing is still meeting regularly on worldwide standardization in both telegraph and telephone communications.

_TELEX IN THE UNITED STATES AND TWX_

In the United States, in November 1931, the Bell Telephone Companies announced an intercommunicating teletypewriter service, called TWX for short (_T_eletype_W_riter e_X_change), by which interconnections could be made by a switchboard operator as in telephone service. One of their first advertisements named it a “Telephone Typewriter Service, a service that typewrites by wire, a method of inter-office communication that has the quickness of the telephone, the flexibility of conversation, the accuracy of the typewriter, the authority of the printed word, the permanency of print.”[13] Tape-punching and tape-controlled transmitting apparatus was provided. This service allowed subscribers to carry on a typewritten conversation at a charge less than the cost of a telephone call, whether to local or to distant areas. The maximum speed of this equipment was limited to sixty words per minute.

There are approximately 54,000 subscribers to TWX at this writing, and the TWX directory gets fatter with each new issue. In 1962 all TWX machines were converted to direct dialing operation, making the service easier to use. Instead of going through “Operator” by manually typing out the call letters of the party being called, one now merely depresses the Originate button, listens for the dial tone, and then dials the TWX number of the party wanted.

RCA Communications, Inc., was the first to extend international TELEX service to Bell System teletypewriter subscribers (1955), enabling them to make and receive overseas calls on their domestic TWX machines.[14] As stated, the TWX machines were geared for 60-words-per-minute operation, whereas the TELEX system operated at 66 words per minute. It was therefore necessary for R.C.A. to use conversion apparatus to an error-detecting code for overseas radio transmission. This code was a seven-unit code, using three marking and four spacing elements, giving 35 usable combinations. By using a special printer, when a faulty combination was received, a special error symbol was printed.

Western Union, in May of 1958, introduced TELEX service between New York City and various Canadian points. By 1962 the service had been extended to 67 United States cities, and at this writing they expect to serve 180 United States cities with an anticipated subscriber capacity of many thousands.[15]

In addition to domestic service between U. S. cities, subscribers can dial automatic teleprinter connections to Canada and Mexico. Also, they can obtain direct TELEX connections to other parts of the world through the overseas facilities of RCAC (Radio Corporation of America Communications), AC&R (American Cable and Radio), and WUI (Western Union International). The operating speed of 66 words per minute and also the teleprinter keyboard in the U. S. TELEX network conform to international standards of the CCITT. This provides complete operating compatibility with other TELEX systems throughout the world without the need for speed and keyboard translators.[15]

SOME OF TODAY’S TELEX APPARATUS