Launched as one of a range of ’70’ series linecasters, the model 79 was specifically designed for use with Teletypesetting (TTS). During TTS a perforated tape was passed through a special attachment on the linecaster. The perforation activated a keyboard and selected the appropriate matrices.
A keyboard operator perforated the tape, encrypting the original text in a series of dots. The tape could be transmitted by telegraph to a reperforator in the printer’s office, which replicated the perforated tape. It was then passed to the linecaster operator.