Bodo, Jean Maurice Emile

In 1872, Bodo first created a multiple-action telegraph with which it was possible to transmit two or more messages on one line. Such a device and all subsequent devices that were created according to the same principle were called start-stop . Prior to this invention, all telegraphic transmissions were carried out using Morse code (i.e., variable length codes). Bodo created a device that transmitted messages (letters of the Latin alphabet and numbers) using fixed-length codes (5 bits).

For this, Bodo created a special 5-bit telegraph code ( Bodo code ), which was subsequently adopted everywhere. It was named the International Telegraph Code No. 1. Two years later, Bodo perfected his invention and created a two-time apparatus that transmitted information at a speed of 360 characters per minute. Two years later he created a five-time apparatus, the transmission rate of which increased fivefold compared to the first, and 2.5 times more than the second. The first such devices were commissioned in 1877 on the Paris-Bordeaux line. Thanks to the Bodo apparatus, it became possible to use the time interval between dashes and points. This was achieved as a result of four or six telegraph operators working on the same line. The most popular were the dual devices, which transmitted information over long distances and were used until the end of the 20th century (?). The transmission speed in such devices was 760 characters per minute. In addition to this apparatus, Bodo developed a dispenser, a decoder, and a printing mechanism. The Bodo apparatus became the most significant achievement of information transmission technology over a distance in the XIX century.