Jean-Maurice-Émile Baudot

Jean-Maurice-Émile Baudot (born 1845, Magneux, France—died March 28, 1903, Sceaux) was an engineer who, in 1874, received a patent on a telegraph code that by the mid-20th century had supplanted Morse Code as the most commonly used telegraphic alphabet.

In Baudot’s code, each letter was represented by a five-unit combination of current-on or current-off signals of equal duration; this represented a substantial economy over the Morse system of short dots and long dashes. Thus, 32 permutations were provided, sufficient for the Roman alphabet, punctuation signs, and control of the machine’s mechanical functions. Baudot also invented (1894) a distributor system for simultaneous (multiplex) transmission of several messages on the same telegraphic circuit or channel.

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. See also teleprinter.