Computer Programming and the Swail Card Reader, 1968-1970


Swail card reader, c.1968

James Swail began developing a series of punch card readers from the mid to late 1960s for the education and vocational training of computer programmers who were blind or partially sighted. Computer programming had already begun to come into its own by this time, and an increasing number of people who were blind or partially sighted had found employment in that field of work already. As Swail observed in 1968, “Since the advent of the computer in common commercial use, an increasing number of blind persons have found employment as programmers. It has turned out that very little adaption need be made for these people…”[1] One aspect of the work that still required sighted assistance, however, was the reading of a punched card. In early computing, a punched card contained the commands or data required to complete assignments. The programmer therefore needed to be able to interpret the information conveyed on the card in order to perform the work required of them.[2]

Although a design for a punched-card reader of this kind had already been developed in the United States, this device was still not practical and difficult to read. As a result, Swail and his colleagues began to design a machine that could enable programmers to quickly and easily read punch cards to complete their work. He produced the first prototype of this punched-card reader in 1968.  Pictured here, it consists of a flat, metal rectangular base plate upon which the card was placed. An operator could manually move a metal carriage over the card along a track attached to the base. A raised scale at the edge of the plate is calibrated in braille numbers zero to eighty in order to indicate the position of the carriage in relation to the card. The carriage itself is marked by a row of twelve pins, with a second braille scale indicating the number of pins. Underneath the carriage is a corresponding row of twelve rollers that are linked to the pins by pivoting arms beneath. The rollers are held against the surface of the card through spring tension. When the roller drops into a hole within the card, the pins rise from their typically flushed position on the device. An operator holds their finger against the surface of the carriage when it is moving along the track over the length of the card, until a pin rises, after which the operator stops the carriage and takes a reading from both corresponding scales. Importantly, this device allowed a card to be read within a matter of seconds.[3]   


Swail card reader, c.1970

Other models of the punch-card reader soon followed, but with significant modifications. Rather than use the mechanical system of the first prototype, by 1970 Swail had built another model of the punched-card reader. Pictured here, it consisted of a similar metal base plate and carriage on a track as the initial design. Rather than use pins and rollers, however, Swail equipped this new device with photocells and vibrators. The carriage, equipped with photocells, would read the card and create a tactual vibrating output through the black screen at the front of the machine with twelve braille markings that represented a calibrated scale.[4]    

[1] James C. Swail, “A Punched Card Reader for the Blind,” Bulletin of the Radio and Electrical Engineering Division, National Research Council of Canada, 18, no.3 (September 1968): 1.

[2] Ibid.

[3] Ibid., 2-3.

[4] Swail card reader, model 5, artifact no. 1985.0821.001, Collections Supplementary Report, Canadian Science and Technology Museum Corporation, Ottawa ON Canada.