Jean-Maurice-Émile Baudot (11 September 1845 – 28 March 1903) was a French engineer known for practical advances in telegraphy. Working in the era of needle and Morse systems, he sought faster, more reliable ways to send and receive written messages over wires.

Major contributions

Baudot is best remembered as an inventor of a keyboard-operated telegraph system and an efficient character code. His method replaced hand-telegraph keying with a punched or keyed mechanism that could be combined with automated printing at the receiver.

He introduced techniques that allowed multiple conversations to share a single line by alternately transmitting time slots — an early form of what is now called time-division multiplexing. These innovations positioned his work within broader developments in telecommunications.

Baudot code and technical features

The code associated with his name, commonly called the Baudot code, is a five-level binary code that encodes letters and control signals. It was designed for mechanical teleprinters and later influenced standardized teleprinter alphabets. Key features included fixed-length characters, separate shift characters to change case or symbol set, and mechanical robustness for high-speed operation.

  • Simple, binary (on/off) signaling suited to electromechanical equipment.
  • Compact codewords enabling continuous, synchronous transmission.
  • Compatibility with printing machines and multiplexed circuits.

Legacy and terminology

Baudot's work helped define the transition from manual telegraphy to automated teleprinter networks and influenced later character encodings used in telecommunication equipment. The term baud was later adopted in his honor to describe signalling speed — the number of symbol changes made to a transmission medium each second — often referred to as a unit of measurement.

Although later electronic codes (and later character sets) superseded his original five-bit layout, the practical problems Baudot addressed — reliable signalling, synchronization, and efficient line use — remain central to digital communications. For historical descriptions and illustrations of his apparatus, consult technical histories of telegraphy and teleprinter development.