The first widely used character code was the Morse Code, developed in 1838 by Samuel F. B. Morse (1791–1872). This two-symbol, dot-and-dash code is capable of representing the characters of the alphabet by varying the number of symbols between one and four. If one considers the symbols to be similiar to bits, then the number character set, 0 to 9, uses 1 to 5 bits.

In 1874 Jean-Maurice Émile Baudot (1845–1903) received a patent for a printing telegraph. He also introduced a code using 5 bits per character. Five bits can be combined in 32 different ways, enough for uppercase letters and a few control characters. To include the number set, Baudot devised a shift to another level, much as the Cap Lock on a keyboard. The shift provides the number set, punctuation symbols, and control character representations for the 32 separate, 5-bit combinations. The control characters include the carriage return and the line feed...