International Computers Limited
International Computers Ltd (ICL) was a large British computer hardware company that was rebranded as the European services arm of Fujitsu in 2002. Significant contracts included Post Office Ltd, Inland Revenue and Ministry of Defence.
History
International Computers Ltd was formed in 1968 from a merger of International Computers and Tabulators (ICT), part of English Electric, and Elliot Automation. This was an initiative under Tony Benn, the UK Minister for Technology , to create a British computer industry that could compete with major world manufacturers like IBM.
International Computers and Tabulators (ICT)
ICT had emerged in the UK with the punch card era with equipment that would process data encoded on punched cards - 40 column cards in the case of ICT - (compared to the 64 or 80 column cards used by IBM and its predecessors).
Initially the data was entered onto punched cards and then verified (by a second operator) prior to processing, hence the job title of Punch Card Operator.
The resulting packs of punched cards were then processed, initially to agree the batch of data with pre-prepared control totals, and then accepted into the operational systems.
Other equipment such as sorters, collators, and tabulators were used to prepare and process the batch(s) of punched cards (hence the term Batch Processing).
The tabulator/accumulators could tabulate (or print) the information from the cards, and although mechanical with typically 120 or 132 hammers would print a line of output (line printing) for each card read. They were also capable of accumulating totals that could be printed as necessary.
Typical operations were for census work, and business tasks such as payroll, invoicing and stock control.
Tabulator connection and punch boxes - The operations were programmed using hard-wired connection boxes that controlled the operations undertaken, the coloums to be totalled, and the fields that identified the type of records, and the needs for sub-totalling and totalling. A different connection box would be prepared for each task and kept for re-use on the particular task.
An additional unit that could be coupled to the rear of the tabulator was a summary punch that would prepare summary cards for each customer, stock item, etc. with totals. These were typically used so that the accumulative results could be output for use in the subsequent period.
These tabulators, by modern computer standards were very large, and occupied an area 6 feet by 4 feet and stood 5 feet tall.
Early Computers - A subsequent additition was a computer, or calculating device, possibly the 553 or 555, that enabled cards to be read in, calculations made, and a new card punched out with the added information.
- I can recall that these devices were expensive for the time, and we bought a day's time from a user that had one. We arrived with a car full of metal trays containing the punched cards and returned with an extra set of updated cards. By the standards of the time these were very fast, but with today's computers similar calculations would be performed in minutes.
The devices of this era, which had substantial mechanical parts, were unreliable and the cards frequently mis-fed or jammed. There were special tools that could retrieve the damaged or jammed cards, hopefully with the information intact.
1900 series
In the 1960s, ICT introduced a range of mainframe computers called the 1900 series. These varied in computing power and the models included the 1901, 1902, 1903, 1904, 1905 and 1906. There was a 1908 at the top end mainly for scientific use.
Enhanced versions subsequently appeared with an A suffix, an E suffix, and a T suffix, e.g. 1901A, 1904T, etc.
The basic memory on the smaller machines was 16k words (or 64 k bytes equivalent), and there were even 8kw versions. despite this apparent small memory size, quite sophisticated applications were run on the equipment and computer programmers paid great attention to the efficient use (and reuse) of memory.
Disc capacity was also very limited and similar attention to ensuring the efficient use of disk space was common. Early machines used storage on reels of magnetic tape and were then augmented by direct access devices (disks) typically with disk capacities of 1.6mb, 4mb and 8mb were the order of the day and occupied a cabinet 4 feet high.
Programming languages used were PLAN (Programming Language Assembler Nineteen-hundred) and latterly COBOL were used for the development of commercial-orientated systems. ALGOL and FORTRAN were used for scientic work.
The operating system used by the 1900 series was GEORGE (meaning to follow) and so GEORGE1, GEORGE2S, GEORGE3 and GEORGE4 etc. were born.
Operating systems and software
- George I (GEneral ORGanisational Environment)
- George II
- George 3
- George 4
- XEKB Cobol compiler
- XEMC Extended Mode (compiler / consolidator?)
- Plan Assembly language
English Electric LEO Marconi (EELM)
Leo computers
- LEO computer Leo 3 - origins in J. Lyons and Co.
(more to follow)
System 4 series
- System 4/50
- System 4/70
- System 4/72
(more to follow)
Elliot computers
4100 (more to follow)
International Computer Ltd (ICL)
2900 series
After the amalgamation of ICT/English Electric/Elliott the 2900 series was introduced that could support the work of the differing ICT and English Electric regimes.
The computer hardware included the 2956, 2960, 2966, 2970, 2972, 2980, 2982 and 2988. These ran the VME and DME (emulation) operating systems.
Series 39
(to follow)
Operating systems and software
- VME/B (Virtual Machine Environment/Bracknell)
- VME/K (Virtual Machine Environment/Kidsgrove)
- VME2900 (Virtual Machine Environment/2900)
- VME (Virtual Machine Environment)
- IDMS(X) (Integrated Data Management System)
- TPMS(X) (Transaction Processing Management System)
- DDS (Data Dictionary System)
- Maple, Staple, SFL assembly languages
2903 range
A cut-down system based more closely upon the 1900 series was introduced as the 2903 range, with a 2904 and a limited 2905 (which was replaced by the 2950). These ran the TME operating system, based very closely upon the GEORGE 1S operating system from the earlier range.
Operating systems and Software
- TME (Transaction Machine Environment)
Dataskil
Dataskil Ltd or ICL Dataskil was a software house that developed commercial programs and some utility software for the ICL marketplace. (more to follow)
Software
- 1900 Datadrive
- 2900 IDH (Interactive Data Handler)
- 2900 PERT
- 2900 LP (Linear Programming)
Bureau services
In the era when the capital cost of purchasing computer equipment and operating computer systems was significant, use was made of organisations that provided such services, commonly known as Computer Bureaux. Alternative uses of these services was when they provided specialist services.
ICSL - International Computer Services Ltd
BARIC
This was a joint venture of ICSL and Barclays Bank, that provided computer services.
Out-sourcing
Some of these organisations, or their sucessors, were involved in the 1980s and 1990s trends to outsourcing of the operation of computer services. (More to follow)
Compatibility
(to follow)
Breakdowns and Maintenance
(to follow)
Compatibility
A major factor in the improvement of computer services was in ensuring compatibility with existing hardware, software and operating systems. The significant investment in the development of systems, which were usually proprietary in nature, resulted in exceptional costs being incurred if a change of supplier was contemplated. This was a form of supplier lock-in that fuelled the demand for common programming languages such as COBOL and the move to lower costs of ownership afforded by open systems. (More to follow)
Merger/takeover by Fujitsu
(to follow)