Ferranti Perseus

Perseus was a vacuum tube (valve) computer built by Ferranti, Ltd of Great Britain. It was a development of the Ferranti Pegasus computer for large-scale data processing.[1] Perseus, which was one of Ferranti's computer systems that included Orion and Sirius,[2] was the company's first production machine marketed towards commercial users.[3] The system used the automatic checking method.[1] Two were sold, both to overseas insurance companies in 1959.[4]


Perseus has two components that functioned independent of each other. The first was the central computer - the processing unit that handled data processing and commercial work.[1] The second was the unit for printing from half-inch magnetic tape.[1] The design aim of Perseus was to enable large-scale data-processing, rather than scientific computing. It used the same electronic technology as the Ferranti Pegasus, similarly engineered. The envisaged applications would involve vast amounts of file data for which 1/2" magnetic tape was provided. The word length was 72 bits with 160 words of random-access memory provided by single-word nickel acoustic delay lines. Unlike Pegasus with its magnetic drum, further internal store was provided by 864, 16-word delay lines.[5] Large-scale data input was provided by punched card readers available for both round- and rectangular-hole cards. Data output was via magnetic tape to an off-line unit equipped with 300 lines per minute Samastronic line printers.[6]


  1. ^ a b c d Hunt 1959.
  2. ^ Reilly, Edwin D. (2003). Milestones in Computer Science and Information Technology. Westport, CT: Greenwood Publishing Group. pp. 98. ISBN 1573565210.
  3. ^ Gandy, Anthony (2012). The Early Computer Industry: Limitations of Scale and Scope. New York: Palgrave Macmillan. p. 175. ISBN 9780230389106.
  4. ^ "Ferranti", Our Computer Heritage Project, Computer Conservation Society, Pegasus, Perseus and Sirius: Delivery List, 2010
  5. ^ Hunt 1959, p. 68.
  6. ^ De Kerf 1959, p. 34.