Firstly, we must stress that we do not have a complete Ferranti Atlas computer!

What we do have is a 39-inch diameter hard disc - this is a magnetic disk supplied (we believe) by Data Products. They utilised moving magnetic heads similarly to today's disk drives. This was the bulk memory and it stored quite a large amount of data for the time. It stored data in 512 word blocks like a magnetic tape. Products like this were subject to destructive contamination - if the magnetic head touched the surface it scraped off magnetic particles which then came between the read/write head and the disk and caused more particles to be created, thus leading to the catastrophic destruction of the disk. This happened occasionally. Data Products were an American company who specialised in printers and disk stores.

The Atlas computer burst onto the scene, in Manchester, during the early 1960s. It was the result of a project, which began in the Department of Electrical Engineering of the University of Manchester in 1956. The group, led by Professor Tom Kilburn, combined those electronic engineers investigating the new Transistor switching circuits and Magnetic Core Storage devices, with the programmers who were familiar with the problems and aspirations engendered by 8 years of using earlier Manchester computing machines for scientific calculations. By 1959 Ferranti Ltd. had joined the project and their collaboration with the University led to the development of the ATLAS computer. Ferranti brought not only their computer design and manufacturing expertise to the project but also their experience in business data processing. The Manchester ATLAS began to provide a computer service in 1962. It went on to provide a reliable service for both scientific and commercial users until 1971.

It embodied many pioneering features, which we now take for granted. These include system features such as, Timesharing of several concurrent computing and peripheral operations, Multiprogramming, and the One-Level Store (Virtual Store).

Design features included, High-speed arithmetic, Asynchronous control, interleaved stores, paging, V-Store (Image Store), Fixed store (ROM), and autonomous transfer units.

Ferranti manufactured two further versions of ATLAS. For a while, in the early 1960s, it was the fastest computer anywhere until being caught by the early Control Data computers from Minneapolis. The other contenders from the United States, the UNIVAC LARC and IBM STRETCH computers, were left behind on their blocks.

Only three Atlas 1 computers were built. The Atlas 2 system was a joint development between Ferranti and Cambridge. The aim was to produce a more modest but largely compatible computer. Even so the commercial price was still well over £1M. Three Atlas 2 Machines were made. The first machine installed was the Cambridge Titan. The other two machines were installed at the Department of Industry's CAD Centre in Cambridge and Aldermaston. Cambridge used the CAD Centre Atlas while Titan was being moved to a new building in 1969.

Manufacturer: Ferranti
Date: 1961

This exhibit has a reference ID of CH1080. Please quote this reference ID in any communication with the Centre for Computing History.