Jean-Maurice-Émile Baudot


Jean-Maurice-Émile Baudot was born on September 11, 1845, in Magneux (Haute-Marne), France. Being the son of a rural farmer he only received primary school education, following which he joined his parents in working on the family farm, a job he did not particularly like. When he was 24 years of age he joined the French Administration of Posts and Telegraphs (1869) where a whole new interesting world of electricity, telegraphy and mechanics awaited him. He took to the new environment with gusto and started studying the different fields with the ultimate aim of becoming a professional engineer – which he finally achieved in 1882.

During his studies he concentrated on improving the efficacy of the telegraphic transmission which was still very slow at that time. The system in use was predominantly based on the Morse system and only achieved speeds of about a dozen words per minute.

Based on the Hughes telegraph he developed his Baudot printing telegraph (1874), a machine that could be operated by anyone. It used a piano-like keyboard - with only five keys – to enter the characters, with each character being a combination of the five keys. This code, which he had developed himself, became known as the Baudot-code. It consisted of five possible positions (like bits) with each position having a possible two states: current on (“1”) or current off (“0”). This basically first digital system had 25 - or 32 - possible combinations. Needing 26 combinations for the alphabet, plus 10 for the numbers, Baudot doubled the number of combinations to 64 by preceding the text with “11111” to indicate letters or “11011” to indicate numbers and special characters. The text to be transmitted could be punched in a paper tape with a central sprocket transport channel; at the one side of the transport channel two holes could be punched, while at the other side there was room for three holes. That way one character at a time (represented by the five positions across what is called a “channel”) could be sent in one go. This obviously increased transmission speed significantly and it did not take long before the more time consuming Morse system was replaced by the much faster Baudot transmitters.

In 1878 Baudot’s equipment was shown at the Universal Exhibition in Paris and he was awarded a Large Gold for his invention. Within a few years Baudot transmitters had been installed successfully between Paris and the main capitals of Europe.

Baudot died on March 28, 1903, in Sceaux near Paris.



Baudot honoured

Baudot has been honoured by having the speed of transmission named after him.
One baud (pronounced bawd) is the unit of measurement for the signaling rate, i.e. the number of changes in the transmission media per second in a modulated signal. For slower speed transmission channels this equates to bits per second or bps. For higher speeds, where multiple bits may be encoded per transmission event, a speed of 600 baud may transmit 2400 bits per second. Hence it comes at no surprise that the term baud has slowly been replaced by the more accurate term bps. But the baud rate of your modem still determines the speed of your dial-up internet connection.



Holes that talk

Baudot’s clever system of recording data in a perforated tape with one 5-bit channel per character resulted in a recording mechanism that the early computers easily adopted. When the computers of the fifties and sixties needed input/output media, apart from punched cards, the Baudot teleprinters and readers had become fast enough by that time to be a meaningful alternative.

Paper tapes using the Baudot system have been frequently shown on stamps to reflect the use of high technology in the early days of computing. Since the introduction of the PC and the internet however they have slowly disappeared from stamps. Using the Baudot code it is sometimes quite interesting to de-cypher the holes in the punched paper tapes of yesteryear as they often carry meaningful messages. It makes the study of these stamps even more interesting.

Turkey issued this stamp in 1975 to showcase its automatic telex network. It’s no surprise that the holes in the paper tape show the text “OTOMATIK TELEKS”.

During the Telecom ’86 Conference in Nairobi Kenya issued a stamp showing the paper tape as bridging the missing link between the telephone and the computer. A bit strange, as a simple cable would have done the job quite easily, but maybe they got carried away with the word play on the “missing link” in palaeonthology. The holes spell the words “MISSING LINK”.

Singapore commemorated World Communications Year 1983 with this stamp showing its telex service. The holes carry the (additional) information “PRIVATE SWITCHING NETWORK”.

This Great Britain meter mark shows the text “X JUMP OVER THE LAZ”. The experienced typist will recognize this fragment as part of the pangram “The quick brown fox jumps over the lazy dog.” A pangram contains all the letters of the English alphabet and was used to test that all the letters on a typewriter, a computer keyboard or a teletype service worked properly – a procedure called “foxing”. Although not a very original text, it is certainly interesting.


The most intriguing use of paper tape in relation to stamps is the case of Estonia. This country at the Baltic Sea had been part of the USSR since 1940. In its drive towards regaining independence – which was achieved on August 20, 1991 - Estonia started issuing its own stamps and used its own postal rates in 1991. Obviously this was unacceptable to the Russian postal authorities who retaliated by no longer sending any postage stamps to Estonia, resulting in a serious shortage of stamps. To alleviate the shortage the director of Eesti Post proposed to use the computer at the Tartu Observatory to produce pieces of paper tape with values which could be used as stamps – clearly the computer had a little program capable of producing these “readable” tapes. The Tartu “stamps” came in white, light-blue and dark-blue paper. Each stamp received a red 30mm h/s Tartu cancel with date 19129100 (December 19, 1991) as proof of authenticity. The value indicated is in Rubles and behind each value is a serial number from 1 to 20. The sale of these Tartu stamps continued till June 20, 1992 when the Ruble was demonetized and the Estonian Kroon was introduced.



            © Wobbe Vegter, 2007






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