International Computers Limited
|Industry||Computer hardware, Computer software|
|Defunct||2002 (34 years)|
|Headquarters||London, United Kingdom|
International Computers Limited, or ICL, was a large British computer hardware, computer software and computer services company that operated from 1968 until 2002 when it was renamed after its parent company, Fujitsu. The company's most successful product line was the ICL 2900 Series range of mainframe computers.
In later years, ICL attempted to diversify its product line but the bulk of its profits always depended on the mainframe customer base. 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. Despite significant sales in overseas markets, ICL's mainframe base was dominated by large contracts from the UK public sector. Significant customers included Post Office Ltd, the Inland Revenue, the Department for Work and Pensions and the Ministry of Defence. ICL also had a strong market share with UK local authorities and (at that time) nationalized utilities including the water, electricity, and gas boards, and the Post Office. In April 2002, ICL migrated its brand to Fujitsu.
Origins of ICL 
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. ICL represented the last step 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 itself a recent merger of Elliott Automation with English Electric Leo Marconi computers. EELM was itself a merger of the computer divisions of English Electric, LEO and Marconi. Upon its creation, the British government held a 10 percent stake in the company and provided a $32.4 million research-and-development grant spread across four years.
On its formation the company inherited two main product lines: from ICT the 1900 Series of mainframes, and from English Electric Computers (EEC) the System 4, a range of IBM System/360-compatible mainframe clones, based on the RCA Spectra 70.
When the companies were first merged the EEC order books were full, while ICT (who had twice as many employees) were struggling, perhaps because it was already obvious that the 1900 series was incompatible with the rest of the industry, with an architecture based on a 24 bit word and 6 bit character rather than the 8 bit byte that was becoming the industry norm.
The new board decided that the 1900 should be phased out in favour of the System 4, but shortly afterwards reversed the decision. It is probable that this was due to union and political pressure from the Wilson government. In any event, most of the original EEC board resigned over the interference as they believed that the 1900 series was doomed from the outset, being incompatible with the rest of the market place. ICL initially thrived, but relied almost wholly on supplying the UK public sector with computers. The 1900s were sold in several countries worldwide, but the largest slice of the market was always in the UK, and the largest part of that in government, local authorities, and nationalised industries.
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 - 40, 80 or 160 column cards in the case of ICT, compared to the 64 or 80 column cards used by IBM and its predecessors.
In 1962 ICT delivered the first ICT 1300 series computer which was 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 produced the Ferranti-Packard 6000 in an astonishingly short period of time, 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 multi task, 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 0001 in the early 1980s) and the United States.
In 1964 ICT purchased the computer division of Ferranti in another government-forced merger. 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 developments, the ones used to develop the FP 6000, were still not on the market. Management looked at the FP 6000 as well as licensing the RCA Spectra 70, an IBM System/360-clone. 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 go on to sell into the thousands.
The 1900 Series, which derived from the Canadian Ferranti-Packard 6000, competed successfully in the UK with the IBM System/360 range from the mid-1960s to the mid-1970s. The basic 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)) were only 15 bit addressing. 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.
At a time (in the 1960s and 1970s) when IBM/360 series 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, i.e. without the need for recompilation. Unfortunately ICT, and later ICL, was unable to capitalise on this major advantage to make significant inroads into IBM's customer base.
English Electric LEO Marconi (EELM) 
During the same period of time, LEO was struggling to produce its own machines that would be able to compete with IBM. Its parent company, J. Lyons and Co., simply didn't 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.
Now with serious financial backing at its disposal, the new company nevertheless decided not to come up with its own design, and instead licensed the RCA Spectra 70 (the design ICT rejected). The result was 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 also supplied to the EELM (later Baric) Bureau subsidiary and installed at Winsford, Cheshire as the hardware for a bureau-developed commercial system for interactive use by bureau customers. Although several multi-user commercial packages (e.g. sales and purchase ledger systems) were developed and trialled 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. Programming languages used were assembler and 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 
Elliott Automation computers 
- Elliott 4100 - A joint development with NCR Corporation. Transferred to ICL but sales and development terminated 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.
ICL locations 
ICL was concentrated in the United Kingdom, with its corporate headquarters in Putney.
At the time of the original merger, the company inherited extensive engineering and manufacturing facilities in West Gorton and Stevenage 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). The company had a large research, operating system and superstructure development and support centre in Bracknell, another smaller one at Dalkeith in Scotland, 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 a former textile mill in Dukinfield and a purpose built factory at Ashton-under-Lyne.
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 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 may exist in a town, for instance with the Putney Headquarters 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.
New Range 
Even before the merger that created ICL was complete, a working party had recommended that the new company should develop a new range of machines offering "acceptable compatibility with the current ranges of both companies". This was also seen as a way to help "achieve company unity" for the newly formed organization. The resulting 2900 Series was launched on 9 October 1974. Its design drew on many sources, one being the Manchester University MU5.
It ran the VME operating systems, and supported emulation of both the earlier architectures (1900 Series and System 4), either standalone (DME, Direct Machine Environment) or concurrently with native-mode operation (CME, Concurrent Machine Environment). In the early 1980s ICL struck a deal to acquire semiconductor technology from Fujitsu, on whom they became increasingly dependent as the years progressed. Eventually Fujitsu acquired ICL, and in 2002 the residue of the company was rebranded as Fujitsu's European services arm.
The computer hardware included:
These ran the VME and DME (emulation) operating systems, and were available in both single and multi-processor configurations, the later being known as Duals and SuperDuals (2966 and 2988 only). The company also developed a
* Content Addressable File Store (CAFS) that could be exploited by the VME file system and ICL 2900 IDMS and
* the world's first commercially available massively parallel computer, the Distributed Array Processor (DAP), that first ran as an attached processor to the ICL 2980.
Series 39 
Series 39 followed the same essential architecture as 2900 series, but was a dramatic step forward in hardware technology. It was the first commercial mainframe to exploit optical fibres for central interconnect, and also introduced a multi-CPU (multinode) architecture transparent to the applications.
The series included:
- Level 30
- Level 50
- Level 60
- Level 80
ICL received the Queen's Award for Technological Achievement for the Series 39 in 1988.
Operating systems 
At the inception of New Range development, two operating systems were planned: System B for the large processors, and System D for the mid-range. System B was subsequently renamed VME/B. A third operating system, System T, was subsequently targeted at small machines. System D was dropped in order to focus efforts on VME/B and System T, renamed to VME/K (Confusingly, VME/B was developed in Kidsgrove, VME/K in Bracknell.) The first large machines (the 2980 and 2970) were launched with VME/B. VME/K first saw service on the 2960.
VME/K development continued independently for several reasons. Early VME/B customers suffered significant performance and reliability problems, and the existence of an alternative product provided a safety net. Perhaps more significantly, VME/K was the brainchild of Ed Mack, who had been brought in by managing director Geoff Cross as ICL's head of research and development. Despite his wide responsibilities, Mack took a detailed personal interest in every aspect of VME/K design. To quote historian Martin Campbell-Kelly, "Mack had a good deal more autonomy than was good for the company." Not only was too much resource going into VME/K at the expense of the VME/B system that ICL's biggest customers were actually using, but the development of mainframe systems was also diverting expenditure from small business systems such as the 2903, whose sales were growing much more rapidly.
ICL's finances deteriorated during the late 1970s, leading to the appointment of a new management team led by Robb Wilmot and Peter Bonfield. One of their first actions was to end VME/K development. This happened just at the time that VME/K had finally reached a level of performance and reliability that made it saleable; however, the customer base was very small, and by this time VME/B (which was renamed VME 2900) had also matured sufficiently to give confidence that it would meet the future requirements for the entire mainframe range.
VME 2900 subsequently became simply VME and then Open VME, and continued to evolve. In 1980 it was marketed as "Your system for the 80s", and indeed that decade proved to be its heyday. It continued (and continues) to give service to many loyal and demanding users, but has attracted few new users since 1990 or so.
Superstructure software 
ICL used the term superstructure to refer to the compilers, data management tools, and transaction processing software sitting above the operating system but below the user application – a category now often labelled middleware.
|IDMS(X)||Integrated Data Management System - a Codasyl database, ported and extended from the IDMS system developed by Cullinane (later Cullinet).|
|TPMS(X)||Transaction Processing Management System - a transaction processing monitor|
|DDS (X)||Data Dictionary System|
|QuickBuild||A package of tools for building applications for Series 39 mainframes built around the Data Dictionary System (DDS).|
|Querymaster||An interactive command-based query language for IDMS databases and indexed-sequential files, offering a relational view of the underlying data sources. Querymaster was based on a Ph. D research project undertaken by Andrew Hutt of ICL during a secondment to Southampton University in 1976.|
|S3||a system programming language derived from ALGOL 68, but with data types and operators aligned to those offered by the 2900 Primitive Level Interface (that is, the order code). This was used to write the VME/B operating system and much of the superstructure, such as compilers and utilities. S3 was not generally used for application-level programming.|
|SCL||System Control Language, VME's equivalent of a job control or shell scripting language|
|COBOL||for most business applications|
|SFL||System Function Language - an assembly language. Used to write VME/K, and 2900 IDMS. Assembly language programming was positively discouraged and the assembler was not available to customers as a standard product, though it could be obtained if there were good reasons.|
|C||C compilers only became available on VME in the mid-1980s, being needed to port relational database products such as Ingres and Oracle. Portability of C applications suffered from the assumptions made by many C programmers that characters would be encoded in ASCII and that short integers would always be 16 bits long (the 2900 architecture allows 32-bit, 64-bit, and 128-bit arithmetic, but 16-bit arithmetic has to be implemented in software and is therefore inefficient).|
|Application Master (AM)||Batch and TP application generation from the Data Dictionary System|
2903 range 
A rapid development to produce a small business computer from, as far as possible, existing hardware and software. It was urgently needed to generate a cash flow that would support continuing 2900 development. The hardware was based on the 2900 DFC (Disk File Controller), and used the MICOS engine. The 2903/4 system cabinet housed the MICOS engine, Drico FEDS disk storage and an absolutely terrible punched card reader. On a wing attached at 45 degrees there was the operators console which was a visual display unit (VDU). For 1900 users who were accustomed to the Westrex teletype as console this was a major advance. The printers abutted to the wing and were initially integrated, much of the logic was held in the system, soon substituted by the CPI shuttle printer and PBS but maintaining their position.
The 2903 used microcode to emulate 1900 hardware. The operating system was George 1* (a modification of George 1S batch operating system) running on top of the UDAS Executive. In consequence, all the normal 1900 compilers and utilities ran on the 290x range without any changes or recompilation.
One major new facility provided on this range was Direct Data Entry, a system comprising up to eight dedicated VDU data entry stations, with which card image files could be created; these could be assigned to a program's card reader and processed accordingly.
There were three models in the range:
- 2905 (limited and was replaced by the 2950)
290x computers would run in an office environment, still quite an innovation for this class of machine, and were a runaway success. Roughly 3000 systems were sold. This was ten times as many as ICL had anticipated.
The smaller machines in the 290x family were replaced in 1980 by the ME29 system.
Operating systems and software 
The 290x operating system, known as 'Executive', allowed the machines to be operated 'manually' via a video console. GEORGE1* ran on top of Executive to control batch processes by means of JCL (Job Control Language), which was based very closely upon the macro language of the 1900 GEORGE1S operating system.
TME (Transaction Machine Environment) 
TME was the operating system on the ME29 and required CL (Control Language) to run jobs - 'manual' operation being discouraged.
Practically all the software packages available on the 1900 range ran on the 290x and ME29 systems.
In about 1982, a new Transaction Processing System TME-TP was introduced for the ME29, with a subset of the facilities of TPMS (cf 2900 software)
Departmental Systems 
For many years ICL marketed departmental computers under the 'DRS' brand, standing originally for Distributed Resource System. During the mid 80s separate Office Systems business units had produced a disparate range of products including IBM-compatible PCs such as the PWS (an AT Clone), small servers branded DRS, and various larger Unix servers sold under the Clan range. A re-branding in late 1988 pulled these together under the DRS brand, with a consistent grey and green livery.
In 1994 the DRS range was superseded by the SuperServer and TeamServer ranges of SPARC and Intel-based machines, running Unix or Microsoft operating systems.
OEM products 
In the early 1970s ICL signed an OEM agreement with the Canadian company, Consolidated Computers Ltd (later Consolidated Computer Inc.) to distribute CCL's key to disk data entry product, Key-Edit in the British Commonwealth of countries as well as in both western and eastern Europe. Models included Key Edit 100, Key Edit 50, 59, 1000, and 2000. In the mid-1980s a version of the Key Edit 59 operating system was ported (in emulation mode) to the DRS 20 series and marketed as Data Entry 20.
Dataskil Ltd or ICL Dataskil was a software house, formed from an internal department known as the User Programming Service (UPS), that developed commercial programs and some utility software for the ICL marketplace. Dataskil also provided consultants and project teams to work on ICL's or direct clients' 1900 and 2900 projects. There were several divisions within Dataskil, including Consultancy Services, Transition Services, etc.
Dataskil software products included:
1900 products 2900 products Other products 1900 Datadrive
2900 IDH (Interactive Data Handler)
2900 LP (Linear Programming)
1900 Filan 
The ICL 1900 Filan manual (1st edition January 1973) describes Filan as:
"a totally integrated system for the analysis of large quantities of complex data such as that collected in censuses and other surveys".
It was used to process the 1971 Indonesian Population Census. In the UK, Filan was used during the 1970s by OPCS (Office of Population Censuses and Surveys) to process the General Household Survey data. As there was only a small user community, ICL decided not to convert the software to run on its 2900 range of computers in the 1980s.
This was a joint venture of International Computer Services Ltd (ICSL), a division of ICL, and Barclays Bank, that provided computer services. In the early days of computing many organizations avoided the capital costs of purchasing their own equipment and the recruitment of technical specialists by putting their work out to service companies which were then known as computer bureaux such as BARIC. This kind of business diminished during the 1980s, only to reappear in the 1990s under a new name –outsourcing. BARIC also ran special groups such as the Advanced Videotex team, which investigated how new technologies such as Prestel could be leveraged. This team was based in Feltham, Middlesex.
ICL had established a presence in India in its earliest days, through a partly owned subsidiary International Computers India Manufacturing (ICIM). As the name implies, ICIM took on some of the manufacturing of ICL-designed equipment, generally for overseas markets. In later years ICIM, from its offices in Pune, started to establish a presence in the market for offshore software development and eventually outsourcing of the operation of computer services. ICIM subsequently became a joint operation with Fujitsu, establishing links to Japan that were as strong as its traditional links to the UK. Reflecting the shift in its business, the company was renamed ICIL (International Computers India Limited), and is now Zensar.
DESC Ltd (subsequently ICL DESC Ltd.) was a subsidiary focused on defence systems spun out from ICL at the time of the Fujitsu takeover to avoid concerns about defence systems ownership by the Japanese firm. These qualms were overcome and eventually it was merged back into the parent company.
iBANK Systems 
iBANK Systems was a joint venture with Xcelsoft, Inc. of Canada to develop a UNIX-based integrated retail banking system capable of distributed operation. Supported platforms included the DRS-6000 and DRS-3000 while the product was written in COBOL with some 'glue' written in C. The international team was based in Greenville SC, US.
The venture lasted from 1992 through 1995 when the two companies dissolved the relationship and each went forward independently, thereby forking the project. The ICL branch was renamed "Fujitsu-ICL International Banking Products". That branch continued operations until 2000 when ICL withdrew completely from all operations in North America. Customers of IBANK Systems included: Moscow Savings Bank (Russia), Suprimex (Russia), Chelind Bank (Russia), Mineral Bank (Bulgaria), Romanian Bank for Development (Romania), PTC (Zimbabwe), People's Own Savings Bank (Zimbabwe), Mutual Bank of the Caribbean (Barbados), National Commercial Bank (Jamaica), and Caisse Populaire (Canada).
Corporate history 
This section describes the various takeovers of and by ICL that followed the formation of ICL in 1969.
Singer Business Machines 
Early in 1976 ICL acquired the international (that is, non-US) part of Singer Business Machines. The Singer group, a holding company which had diversified by adding many divisions, the most well-known of which was its early roots in sewing machines, and others such as the Business Machine division which was acquired in 1970 by purchasing Friden, a San Leandro computer company, whose flagship product was the System Ten, a small business minicomputer. SBM had also acquired Cogar Corporation, a manufacturer of desktop intelligent terminals in Utica, New York, which after the ICL acquision became the development and manufacturing plant for both minicomputers and terminals. The acquisition shifted the geographical balance of ICL's sales away from the UK, and also gave a presence in industry markets such as retail and manufacturing. ICL subsequently developed the System Ten into the System 25, and used the product to spearhead the growth of its Retail Systems business during the 1980s.
On 26 July 1984 a takeover bid for ICL arrived from Sir Kenneth Corfield, head of Standard Telephones and Cables. The stated rationale was the predicted convergence of computers and telecommunications. To the bemusement of many ICL staff, Corfield also announced that he thought ICL's marketing skills would complement STC's technical strengths. The ICL board recommended acceptance of the bid, and the takeover was completed on 10 September 1984. Sir Michael Edwardes, who had been chairman for just six months, resigned, and Christopher Laidlaw became Chairman. Robb Wilmot, who had arrived as Managing Director in 1981 (at the age of only 36), remained, along with Peter Bonfield as Marketing Director.
The merger was soon followed by a financial crisis in STC, leading to Corfield's replacement by Lord Keith as chairman, with Arthur Walsh as chief executive. Wilmot resigned, and Peter Bonfield was appointed chairman and managing director of ICL. Within a few years ICL was contributing 60% of the profits and turnover of the combined group. Bonfield was appointed CBE for his role in turning the company around.
In 1988 STC acquired US retail systems specialist Datachecker Systems from National Semiconductor Corporation. At the time this was the second largest supplier in the US retail market, and greatly expanded ICL's US presence.
In 1989, ICL acquired Regnecentralen of Denmark, a company with a distinguished history and reputation in that country, but which was best known internationally for its front-end communications handling equipment.
Computer Consoles Inc 
Also in 1989 STC acquired CCI, suppliers of ICL's Clan 5, 6 and 7 ranges (later DRS 500) and originator of OfficePower. By 1990 CCI's Computer Products Division in Irvine, California and Office Products Centre in Reston, Virginia had been transferred to ICL.
Nokia Data 
In 1991 ICL acquired Nokia Data, part of the Finnish Nokia Group. Nokia Data was itself the result of Nokia's mid-1980s acquisition of Ericsson Information Systems, whose origins lay in the purchase by Ericsson of the computer business of Saab, known as Datasaab. ICL's acquisition (at a price of around £250m) added 9500 employees to the company (7000 of them in Finland and Sweden), and brought with it a PC manufacturing capability, a suite of desktop software products, and more importantly a strong presence in the Nordic market and an awareness of the high-volume end of the IT market.
ICL KME-CS 
In July, 1991 ICL acquired more than half of the Russian company KME-CS (Kazan Manufacturing Enterprise of Computer Systems, Kazan, Tatarstan, Russia). The agreement was signed between Peter Bonfield (President of ICL) and Mintimer Shaimiev (former President of the Tatarstan Republic).
ICL's relationship with Fujitsu started in 1981, when ICL needed a cheaper source of technology to develop lower-end machines in the 2900 range to compete with the IBM 4300 series. At this stage ICL was developing its own LSI technology for use in the higher-end machines, designed as a successor to the highly successful 2966 processor (known internally as S3). ICL had visited a number of companies during 1980 including Fujitsu and Hitachi to identify potential suppliers.
In early 1981 ICL ran into a financial crisis, leading to a full takeover bid from Univac; but the British Government stepped in with a loan guarantee, enabling the company to stay independent. As part of this rescue agreement, Robb Wilmot arrived as CEO in May 1981.
Wilmot cancelled ICL in-house LSI technology development, and negotiated an agreement that gave access to Fujitsu's LSI and packaging technologies, which, when combined with ICL's in-house CAD capability, enabled ICL to design and manufacture the DM1 and Estriel machines, later marketed very profitably as Series 39 level 30 and 80.
Initially the collaboration with Fujitsu was presented as being an arm's length one, to avoid diluting ICL's credentials as a European and British company. However, Fujitsu's involvement with ICL at both the financial and the technical level steadily increased over the subsequent two decades, leading first to 100% ownership and subsequently to the full integration of ICL into the Fujitsu company and the dropping of the ICL brand.
In 1990 Fujitsu acquired 80% of ICL plc from the parent STC plc, paying USD 1.29 billion.
Fujitsu Siemens 
Following the acquisition of Nokia Data in 1991, personal computers and servers were marketed under the ICL brand. This changed when Fujitsu Siemens Computers was formed in 1999 as a joint venture between Fujitsu and Siemens. The joint venture absorbed all ICL's hardware business with the exception of VME mainframes, and all the business of Siemens Nixdorf with the exception of its banking and retail systems. Fujitsu Siemens in turn was merged back into Fujitsu in 2009.
PC Interworks Ltd 
History PC Interworks was incorporated in October 1995. It was created as a sales company, selling Personal Computer and other IT equipment to the employees of large organisations. The Company evolved from a tried and tested concept within the British computer company ICL, (International Computers Ltd, now Fujitsu Services). PC Interworks began business with a contract from ICL to provide computer related products to its staff, as a part of its Employee Benefit Programme. PC Interworks was absorbed by International Computer Logistics.
See also 
- Odra (computer) The Polish Odra 1300 series computers used ICL software
- ICL: A Business and Technical History. Martin Campbell-Kelly, Clarendon Press, 1989. ISBN 0-19-853918-5
- ICL and Europe. Virgilio Pasquali. In Resurrection, the Bulletin of the Computer Conservation Society, Summer 2005
- Trojan Horses and National Champions: A History of the European Computing and Telecommunications Industry. Paul Gannon. Apt-Amatic Books, 1997. ISBN 0-9530284-0-2
- Oral history interview with Arthur L. C. Humphreys, Charles Babbage Institute, University of Minnesota
- Lee, John M. "Britain to Finance Computer Merger", The New York Times. June 12, 1968. Page 61. Retrieved March 16, 2011.
- PC Magazine http://www.pcmag.com/encyclopedia_term/0,2542,t=QuickBuild&i=50086,00.asp
|url=missing title (help).
- Carmichael, Hamish (1996). An ICL Anthology. Laidlaw Hicks. p. 113. ISBN 0-9527389-0-2. Retrieved 2011-05-06. "In the 2903, all the mechanics of the peripherals were controlled by programming in the central processor rather than by their own electronics. Of particular note was the pair of instructions to switch the card reader’s ‘picker’ solenoid on and off. The solenoid was rated for dissipating heat on the basis of only being ‘on’ for extremely short periods. This led to the famous software failure known as ‘select card reader and catch fire’."
- Knight, Michael (2009). "The Seizing of Singer". Computer Resurrection (49). ISSN 0958-7403.
- The Jim Austin Computer Collection
- Irvine signs on, STC Gazette February 1990, STC PLC
- Fujitsu Services Ltd
- ICL 1900 Series Computers at fsu.eu.com
- ICL 2900 Series Computers at pink-mouse-productions.com
- The ICL Archive - an on-line directory of ICL archive material maintained by the Computer Conservation Society.
- The EMAS environment at Edinburgh University
- ICL Computer Museum