Perseus was a

vacuum tube A vacuum tube, electron tube, thermionic valve (British usage), or tube (North America) is a device that controls electric current flow in a high vacuum between electrodes to which an electric voltage, potential difference has been applied. It ...

(valve) computer built by

Ferranti Ferranti International PLC or simply Ferranti was a UK-based electrical engineering and equipment firm that operated for over a century, from 1885 until its bankruptcy in 1993. At its peak, Ferranti was a significant player in power grid system ...

Ltd of

Great Britain Great Britain is an island in the North Atlantic Ocean off the north-west coast of continental Europe, consisting of the countries England, Scotland, and Wales. With an area of , it is the largest of the British Isles, the List of European ...

. It was a development of the

Ferranti Pegasus Pegasus was an early British vacuum-tube (valve) computer built by Ferranti Ltd that pioneered design features to improve usability for both engineers and programmers. It was originally named the Ferranti Package Computer as its hardware desig ...

computer for large-scale data processing. Perseus, which was one of Ferranti's computer systems that included

Orion Orion may refer to: Common meanings * Orion (constellation), named after the mythical hunter * Orion (mythology), a hunter in Greek mythology Arts and media Fictional entities Characters and species * Orion (character), a DC Comics c ...

and

Sirius Sirius is the brightest star in the night sky. Its name is derived from the Greek word (Latin script: ), meaning 'glowing' or 'scorching'. The star is designated Canis Majoris, Latinized to Alpha Canis Majoris, and abbr ...

, was the company's first production machine marketed towards commercial users. The system used the automatic checking method. Two were sold, both to overseas insurance companies in 1959.

Design

Perseus has two components that functioned independently of each other. The first was the central computer – the processing unit that handled data processing and commercial work. The second was the unit for printing from half-inch

magnetic tape Magnetic tape is a medium for magnetic storage made of a thin, magnetizable coating on a long, narrow strip of plastic film. It was developed in Germany in 1928, based on the earlier magnetic wire recording from Denmark. Devices that use magnetic ...

. 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 Random-access memory (RAM; ) is a form of Computer memory, electronic computer memory that can be read and changed in any order, typically used to store working Data (computing), data and machine code. A random-access memory device allows ...

provided by single-word nickel acoustic delay lines. Unlike Pegasus with its

magnetic drum Drum memory was a magnetic data storage device invented by Gustav Tauschek in 1932 in Austria. Drums were widely used in the 1950s and into the 1960s as computer memory. Many early computers, called drum computers or drum machines, used dru ...

, further internal store was provided by 864, 16-word delay lines. 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 printer A line printer Printer (computing), prints one entire line of text before advancing to another line. Most early line printers were printer (computing)#Impact printers, impact printers. Line printers are mostly associated with unit record eq ...

Old Mutual (South Africa)

The South African Mutual Life Assurance Society (Old Mutual) had a Perseus installed at their head office in Pinelands, Cape Town in 1960. It is considered one of the earliest computers in South Africa. Many years later an eagle-eyed employee spotted some of the decommissioned Perseus enclosures at the back of the building, ready to be scrapped. He discovered that they were in fact aluminium and stamped inside it said "Made by Rolls Royce"! The staff member purchased the about-to-be-scrapped enclosures for next to nothing and eventually built himself a sports car from the "Made by Rolls Royce" aluminium sheet metal! It is safe to assume that every Perseus sold was clad in enclosures made by Rolls Royce.

References

Bibliography

* * * * Vacuum tube computers 1950s computers

Perseus In Greek mythology, Perseus (, ; Greek language, Greek: Περσεύς, Romanization of Greek, translit. Perseús) is the legendary founder of the Perseid dynasty. He was, alongside Cadmus and Bellerophon, the greatest Greek hero and slayer of ...

Early British computers {{Compu-stub