Emile Baudot By Johnny Jung
Emile Baudot was born in 1845, Magneux, France and died on March1903, Sceaux.
Mr. Baudot was of a modest origin. He was the son of a farmer, he had begun his life following the career of his parents; but in 1869, he entered the Administration of Posts and Telegraphs, of which he would become the glory.
Emile Baudot
developed a printing telegraph machine which used a typewriter style keyboard,
this allowed virtually anyone to send and receive telegraph messages. Baudot
used a different type of code for his system because Morse code didn't lend
itself to automation, this was due to the uneven length and size of bits
required for each letter.
Baudot used a five bit code to represent each character, this would normally only give 32 possible combinations (00000 to 11111 = 32). It clearly wasn't enough for 26 letters and 10 digits but he got around this problem by using two 'shift characters' for figures and letters, which performed the same sort of function as a typewriter shift key. Now he had 62 combinations for letters, figures and punctuation marks. To this day, the speed of serial communications is still measured in Baud rate, after Emile Baudot., in 1874 he received a patent on a telegraph code that by the mid-20th century had supplanted Morse Code as the most commonly used telegraphic alphabet.
Modern versions of the Baudot Code usually use groups of seven or eight "on" and "off" signals. Groups of seven permit transmission of 128 characters; with groups of eight, one member may be used for error correction or other function.
It was in August, 1874 that he received his first patent on a telegraph code that by the mid-20th century had supplanted Morse Code as the most commonly used telegraphic alphabet.
November 12, 1877 was when the first
on-line tests of his system took place between Paris and Bordeaux. The Baudot apparatus installed at the
Universal Exhibition of 1878 won him the great gold medal and the unanimous
congratulations of the engineers of the entire world.
During this period of twenty years, Baudot installations multiplied in France and spread in foreign countries, everywhere assuring excellent service in doubling, tripling, or quadrupling the efficiency of the wires.
At the end of 1877, the Paris-Rome line (about 1700km), a difficult operation for the Hughes, began to be served by a double Baudot. The first telegrams transmitted were those announcing the election of Mr. Carnot to the presidency of the French Republic.
Since then, the Baudot has been installed successively between Paris and Vienna, between Paris and Berne, between Paris and Berlin, between Paris and London, and between Hamburg and le Havre. In the same time, it has been adopted for interior service in Italy, in the Netherlands, in Spain, in Brasil, etc.
In these times, Mr. Baudot solved with his apparatus the most varied and the most interesting problems.
In July, 1887, he undertook tests crowned with success between Weston and Waterville on the cable of the "Commercial" Company; the apparatus experimented with was a double Baudot installed in duplex. The Baudot transmitters and receivers were substituted purely and simply for the recorder.
On August 8, 1890, he assured, on a single wire, discrete relations between the three towns of Paris, Vannes, and Lorient, inaugurating at this date the spread-out posts that were later so much generalized.
On April 27, 1894, he established, always over a single wire, communications between the Paris stock exchange and the Milan stock exchange, and at the same time between the central Paris and central Milan, and invented for this occasion the retransmitter.
On January 3, 1894, he served with a triple apparatus the underground wires from Paris to Bordeaux that functioned painfully with the Hughes.
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Here is a chart that shows all the possible Baudot combinations: |
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Sources:
http://www.enteract.com/~enf/baudot/necrologie.html
http://www.enteract.com/~enf/baudot/son-oeuvre.html
http://www.acm.inf.ethz.ch/ProblemSetArchive/B_US_EastCen/1988/baudot.htm
http://www.cinemedia.net/SFCV-RMIT-Annex/rnaughton/BAUDOT_BIO.html