Titan was the prototype of the Atlas 2 computer developed by

Ferranti Ferranti or Ferranti International plc was a UK electrical engineering and equipment firm that operated for over a century from 1885 until it went bankrupt in 1993. The company was once a constituent of the FTSE 100 Index. The firm was known ...

and the University of Cambridge Mathematical Laboratory in

Cambridge Cambridge ( ) is a university city and the county town in Cambridgeshire, England. It is located on the River Cam approximately north of London. As of the 2021 United Kingdom census, the population of Cambridge was 145,700. Cambridge beca ...

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe ...

. It was designed starting in 1963, and in operation from 1964 to 1973.

History

In 1961, the

University of Cambridge , mottoeng = Literal: From here, light and sacred draughts. Non literal: From this place, we gain enlightenment and precious knowledge. , established = , other_name = The Chancellor, Masters and Schola ...

found itself unable to fund a suitably powerful computer for its needs at the time, so the University purchased from Ferranti the main Atlas processing units and then jointly designed the memory and peripheral equipment. The joint effort led to a cheaper and simpler version of the Atlas that Ferranti could market, leaving Cambridge with the prototype version, named Titan. The Atlas hardware arrived in Cambridge in 1963, although software design was already underway. David Wheeler was in charge of the joint effort between the University and Ferranti. In 1965 the Cambridge side of the team decided to add a time-sharing facility for Titan, necessitating the acquisition of additional hardware. When Titan came into full service in 1966, time sharing was available for all staff. Titan was finally switched off in October 1973. Ferranti, by then a division of International Computers and Tabulators (ICT), marketed the Titan as the Atlas 2. Although intended to be more affordable than the Atlas, its price was still over £1 million. A second Atlas 2 was built in Manchester, and was installed at the Computer-Aided Design Centre ( CADCentre) on Madingley Road together with the Cambridge Titan supervisor. This machine, the last Atlas, was finally switched off on 21 December 1976. A third Atlas 2 was ordered by the UK's Atomic Weapons Research Establishment (AWRE) at Aldermaston. It replaced the faster and much more expensive IBM 7030 Stretch which had been leased from IBM.

Hardware

Titan differed from the original Manchester

Atlas An atlas is a collection of maps; it is typically a bundle of maps of Earth or of a region of Earth. Atlases have traditionally been bound into book form, but today many atlases are in multimedia formats. In addition to presenting geograp ...

by having a real, but cached, main memory, rather than the paged (or virtual) memory used in the Manchester machine. It initially had 28K of memory, but this was expanded first to 64K and later to 128K. The Titan's main memory had 128K of 48-bit words and was implemented using ferrite

core store Magnetic-core memory was the predominant form of random-access computer memory for 20 years between about 1955 and 1975. Such memory is often just called core memory, or, informally, core. Core memory uses toroids (rings) of a hard magnetic ...

rather than the part core, part rotating drum-store used on the Manchester Atlas. Titan also had two large hard-disk drives and several magnetic tape decks. As with the Manchester Atlas, it used discrete components, in particular germanium

transistor upright=1.4, gate (G), body (B), source (S) and drain (D) terminals. The gate is separated from the body by an insulating layer (pink). A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch ...

s. Some of these components can be seen in the online relics collection of the University of Cambridge Computer Laboratory.

Uses

Titan was the computer on which a team from Ferranti based in Bracknell working with David Barron, David Hartley, Roger Needham and Barry Landy of Cambridge University Maths Lab developed the early multi-user time-sharing

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ef ...

called Titan Supervisor. This was arguably the world's first commercially sold time-sharing operating system. Other experiments in time-sharing, such as CTSS and

PLATO Plato ( ; grc-gre, Πλάτων ; 428/427 or 424/423 – 348/347 BC) was a Greek philosopher born in Athens during the Classical period in Ancient Greece. He founded the Platonist school of thought and the Academy, the first institutio ...

in the US, were one-of-a-kind research projects. One of Titan's most intensive uses was to compute the inverse Fourier Transforms of data from the One-Mile Radio Telescope.

References

{{DEFAULTSORT:Titan (Computer) 1964 establishments in the United Kingdom 1973 disestablishments in the United Kingdom Ferranti computers History of Cambridge Transistorized computers University of Cambridge Computer Laboratory 20th century in Cambridge