In addition to the 5-bit Baudot code and the much later seven-bit ASCII code, there was a six-bit code known as the TTS code (Teletypesetter) used by news wire services. Through the use of "shift in" and "shift out" codes, this six-bit code could represent a full set of upper and lower case characters, digits, symbols commonly used in newspapers, and limited typesetting instructions such as "flush left" or "center". A Model 20 Teletype machine with a punch ("reperforator") was installed at subscriber newspaper sites. Originally these machines would simply punch paper tapes and these tapes could be read by a tape reader attached to a Linotype machine, creating type for printing in newspapers and magazines. In later years the incoming 6-bit current loop signal was coupled directly into a minicomputer or mainframe for storage, editing, and eventual feed to a phototypesetting machine.
Read more about this topic: Teleprinter