Engraving by Kohl. French engineer Emile Baudot (1848-1903) invented the first digital telecommunication code in 1870. He also perfected the electro-mechanical hardware to send his code. This system allowed up to six operators to send messages on the same communications line, the first practical use of multiplexing in telecommunications. Illustration from 'Electricity and Magnetism' by Amedee Guillemin (1826-1893), published in London in 1891.
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