International Computers Limited (ICL) was a British computer hardware, computer software and computer services company that operated from 1968 until 2002. It was formed through a merger of International Computers and Tabulators (ICT), English Electric Computers (EEC) and Elliott Automation in 1968. The company's most successful product line was the ICL 2900 Series range of mainframe computers.
In later years, ICL diversified its product line but the bulk of its profits always came from its mainframe customers. New ventures included marketing a range of powerful IBM clones made by Fujitsu, various minicomputer and personal computer ranges and (more successfully) a range of retail point-of-sale equipment and back-office software. Although it had significant sales overseas, ICL's mainframe business was dominated by large contracts from the UK public sector, including Post Office Ltd, the Inland Revenue, the Department for Work and Pensions and the Ministry of Defence. It also had a strong market share with UK local authorities and (at that time) nationalised utilities including the water, electricity, and gas boards.
The company had an increasingly close relationship with Fujitsu from the early 1980s, culminating in Fujitsu becoming sole shareholder in 1998. ICL was rebranded as Fujitsu in April 2002. Fujitsu (UK) as the hardware and software supplier has been implicated in the British Post Office scandal, which has extended from the 1990s to the 2020s. The ICL brand is still used by the former Russian joint-venture of the company, founded in 1991.
Origins
International Computers Limited was formed in 1968 as a part of the Industrial Expansion Act of the Wilson Labour government. ICL was an initiative of Tony Benn, the Minister of Technology, to create a British computer industry that could compete with major world manufacturers like IBM; the formation of the company was the last in a series of mergers that had taken place in the industry since the late 1950s.
The main portions of ICL were formed by merging International Computers and Tabulators (ICT) with English Electric Computers, the latter a recent merger of Elliott Automation with English Electric Leo Marconi computers, which itself had been a merger of the computer divisions of English Electric, LEO and Marconi. Upon its creation, the British government held a 10% stake in the company and provided a $32.4 million research-and-development grant spread across four years.
International Computers and Tabulators (ICT)
ICT was itself the result of a merger of two UK companies that had competed with each other throughout the 1930s and 1940s during the punched card era: British Tabulating Machine Company (BTM) and Powers-Samas. ICT had thus emerged with equipment that would process data encoded on punched cards with 40, 80 or 160 columns, compared to the 64 or 80 columns used by IBM and its predecessors.
In 1962, ICT delivered the first ICT 1300 series computer, its first transistor machine and also the first to use core memory. A small team from Ferranti's Canadian subsidiary, Ferranti-Packard, visited the various Ferranti computer labs and saw their work on a next-generation machine. On their return home they quickly produced the Ferranti-Packard 6000, developing the machine, compilers and an operating system (before these were common) and putting it on the market by 1963. A feature of the Executive operating system was its ability to multitask, using dynamic memory allocation enabled with a magnetic drum as an intermediate random access device. The machine went on to have some success and sold in small numbers in Canada (Saskatchewan Power Corporation retired serial number 0004 in early 1982) and the United States.
In 1964, ICT purchased the computer division of Ferranti via a government-mandated transaction. Ferranti had been building a small number of scientific machines based on various university designs since the 1950s. None of these could be considered commercially successful, however, and Ferranti always seemed to be slow bringing its designs to market.
Meanwhile, ICT management in England was looking to rejuvenate their line-up; their latest ideas, which had gone into the FP 6000 in Canada, were still not on the market. Management looked at the FP 6000 as well as licensing the RCA Spectra 70. In the end, it was decided to go with the FP 6000 as the basis for a small line of small-to-midrange machines. The result was the ICT 1900 series, which would eventually sell into the thousands and compete in the UK with the IBM System/360 range from the mid-1960s to the mid-1970s. The design was based on a 24-bit word, divided up into 6-bit characters; lower case and control characters were provided for by "shift" characters. The early machines (1904/1905 with hardware floating point) had only 15-bit addressing, but later machines (1904E, 1905E, 1906A) had extended addressing modes, up to 22 bits.
The operating systems (Executives) were:
E4BM – the original for the FP 6000 (known internally as the FP1) E4RM – a significantly rewritten version of E4BM, with parts of the operating system overlaid to save space E6BM – a rewritten version of E4BM for the later machines with 22 bit addressing E6RM – a rewritten version of E4RM overlay software for the later machines with 22 bit addressing
A later development was GEORGE3, remembered with great affection by a generation of British programmers.
A series of smaller machines were developed by the ICL Stevenage operation, consisting initially of the 1901 / 1902 / 1903 systems running E3 series executives (e.g. E3RM) and versions of the GEORGE operating system (initially GEORGE1). Later developments were the 1901A / 1902A / 1903A with their own Executives and GEORGE2.
In contrast to many computers of the 1960s and 1970s, such as IBM/360 series, where programs had to be recompiled to run in different machine and/or operating system environments, one significant feature of the 1900 series was that programs would function unaltered on any 1900 system, without the need for recompilation.
English Electric LEO Marconi (EELM)
During the same period, LEO was struggling to produce its own machines that would be able to compete with IBM. Its parent company, J. Lyons and Co., did not have the financial might to develop a new line of machines. Not wanting to see its work go to waste, it sold its computer division to English Electric. That company had developed a series of machines over the years, notably the KDF9 and the commercially oriented KDF8.
Having secured considerable financial backing, the new company nevertheless decided not to produce its own design, and instead licensed the RCA Spectra 70 (the design ICT rejected); this arrangement resulted in the System 4 series. While there were a number of models in the range, the smaller 4/10 and 4/30 were seen as underpowered, and the more successful variants were the larger 4/50 and 4/70 models. A model 4/75 was supplied to the EELM (later Baric) Bureau subsidiary and installed at Winsford, Cheshire for interactive use by bureau customers. Although several multi-user commercial packages (e.g. sales and purchase ledger systems) were developed and tried with customers, this was not commercially successful, and the service was soon withdrawn.
The System 4 series ran the J (for Job) operating system. This was a batch operating system, although there was a variant that allowed interactive access called MultiJob. Under a framework called Driver, J was a successful operating environment for high-volume commercial real-time systems. The programming languages were assembler, COBOL and Fortran (an Algol 60 compiler was provided but not used much, if at all). The system was controlled from a console composed of a mechanical printer and keyboard – very like a Teletype. The assembly language (known as Usercode) non-privileged instruction set was identical to IBM System 360 Assembly Language; in privileged mode there were a few extras.
System 4's compatibility with the IBM 360 made it particularly attractive to customers in Eastern Europe and the Soviet Union, as the sale and installation of IBM computers (and other American technologies) there was politically sensitive and commercially restricted during the Cold War.
Leo computers LEO computer Leo 3 – origins in J. Lyons and Co.
Elliott Automation computers Elliott 4100 – a joint development with NCR Corporation. Transferred to ICL but sales and development ended soon after the formation of ICL.
The following remained with Elliott Automation and were never included in the formation of ICL:
Elliott 503 – extensively used for academic and scientific work in British universities Elliott 803 Elliott 901 / 920A Elliott 903 / 920B Elliott 905 / 920C Elliott 920ATC
The 900 series were 18 bit binary computers. The 90x series were commercial machines. The 920x series were built to military specifications and used in military aircraft, mobile field deployed air defence systems and tanks.
Locations
ICL was concentrated in the United Kingdom, with its corporate headquarters in Putney in the London borough of Wandsworth.
At the time of the original merger, the company inherited extensive engineering and manufacturing facilities in West Gorton, Manchester; Castlereagh in Belfast, Stevenage and Croydon from ICT, and from English Electric in Kidsgrove, Staffordshire and Winsford, Cheshire. Manufacture and assembly also took place at several factories in Letchworth Garden City (the original home of the British Tabulating Company) and Croydon.
The company had a large research, operating system and software development and support centre in Bracknell, another smaller one at Dalkeith in Scotland and a software development centre in Adelaide, South Australia, between 1970 and 1973, application development in Reading, and training centres at Moor Hall (Cookham), Beaumont College (Old Windsor) (sales, support and software) and Letchworth (Hertfordshire) (manufacturing & field engineering).
The company also had manufacturing facilities in Park Road Mill, Dukinfield; later replaced by a purpose-built factory at Ashton-under-Lyne.Ashton under-Lyne's team was noted for working on numerous mechanical innovations in the field of computer engineering. A state of the art printed circuit board plant was built in Plymouth Grove, Manchester in 1979, however financial troubles within the company forced its closure in 1981. Other offices included a facility at Bridgford House in Nottingham which was the headquarters of Rushcliffe Borough Council, but has since been converted into apartments.
For some years ICL maintained a training and presentation facility for senior management at Hedsor House, near Taplow, Berkshire.
Outside the UK, ICL's offices around the world were mainly sales and marketing operations, with some application development for the local market. The exceptions were development and manufacturing sites arising from acquisitions, such as Utica, New York in the United States from the Singer merger, and a variety of former Nokia Data sites in Sweden and Finland.
ICL and its customers often referred to these locations by the Site Code, especially where multiple sites might exist in a town, for instance with the Putney headquarters building (now Putney Wharf Tower) being LON11 (London 11), the training college at Beaumont being WSR01 (Windsor 01) and the southern System Support Centre (SCC) at Bracknell, Berkshire being BRA01 (Bracknell 01). BRA05 was the new headquarters of ICL (UK) Ltd, the company's UK sales and customer service division which moved from its original base at Putney Bridge House (LON13) in Fulham, London to a new building in Bracknell in the late 1980s.
Early products: 1900 Series and System 4