One of the earliest mechanisms for inputting programs or data into digital computers was through the use of paper tape. The tape, typically 2 cm in width, would be coded by punching a series of holes in the tape using a keyboard-based “paper-punch”. The tape was then read and turned into electrical signals for input to the computer by passing it under an optical reader. The earliest tapes had six rows which allowed a possible 64 (26) possible different characters. Later, slightly wider-versions of tape added two more rows permitting a factor of four increase (28) in characters. The correction device was used to correct errors in the tape. It could be used to punch additional holes if they had been missed or a typing error had occurred, or if a major error occurred, a section of tape could be cut and spliced and the correct holes could be made in the blank splice. This unit, which was used for the eight-row version of tape, was manufactured by the Electodata division of Burroughs. The aluminum base measures 8 cm by 3.8 cm. Note that paper tape was often used for the output of the early computers as well. It could then be read and printed by the associated printers.
