International Computers and Tabulators
Encyclopedia
International Computers and Tabulators or ICT was formed in 1959 by a merger of the British Tabulating Machine Company
(BTM) and Powers-Samas
. In 1963 it also added the business computer divisions of Ferranti
. It exported computers to many countries around the world and went on to become part of International Computers Limited (ICL).
computer before the acquisition of the EMI
Computing Services Division who designed and produced it.
The ICT 1201 computer used thermionic valve
technology and its main memory was drum storage
. Input was from 80-column punched card
s and output was to 80-column cards and a printer
. Before the merger, under BTM, this had been known as the HEC4 (Hollerith
Electronic Computer, fourth version).
The ICT 1301
, and its smaller cousin the ICT 1300, used germanium
transistor
s and core memory
. Backing store
was magnetic drum
, and optionally one-inch-, half-inch- or quarter-inch-wide magnetic tape
. Input was from 80-column punched cards and optionally 160-column punched cards and punched paper tape
. Output was to 80-column punched cards, printer and optionally to punched paper tape. The first customer delivery was in 1962, a 1301 sold to the University of London
. One of their main attractions was that they performed British currency calculations (pounds, shillings and pence
) in hardware. They also had the advantage of programmers not having to learn binary
or octal
arithmetic as the instruction set
was pure decimal and the arithmetic unit
had no binary mode, only decimal or pounds, shillings and pence. Its clock
ran at 1 MHz. The London University machine still exists (January 2006) and is being reinstated to working condition by a group of enthusiasts.
The ICT 1302 used similar technology to the 1300/1301 but was a multiprogramming
system capable of running three programs in addition to the Executive
. It also used the 'Standard Interface' for the connection of peripheral
s allowing much more flexibility in peripheral configuration. The 'Standard Interface' was originally prototyped on the 1301 and went on to be used on the 1900 series.
The ICT 1500 series was a design bought in from the RCA Corporation
, who called it the RCA 301. RCA also sold the design to Siemens
in Germany and Compagnie des Machines Bull
in France who called it the Gamma 30. It used a 6 bit byte
and had core stores of 10,000, 20,000 or 40,000 bytes.
The ICT 1900 series
was devised after the acquisition of Ferranti's assets which brought in the new Ferranti-Packard 6000
machine from Ferranti's Canadian
subsidiary, which was considerably more advanced than the existing 130x line. It was decided to adapt this machine to use the 'Standard Interface', and it was put on the market as the ICT 1904
, the first in a range of upward-compatible computer systems.
In 1968 ICT merged with English Electric Computers, itself formed from the prior mergers of English Electric Leo Marconi (EELM) and Elliott Automation. The resulting company became International Computers Limited (ICL). At the time of the merger English Electric Computers was in the process of making a line of large IBM System/360-compatible mainframes based on the RCA Spectra 70
, which was sold as the ICL System-4. Both 1900 and System-4 were eventually replaced by the ICL 2900 Series
which was introduced in 1974.
British Tabulating Machine Company
The British Tabulating Machine Company was a firm which manufactured and sold Hollerith unit record equipment and other data-processing equipment...
(BTM) and Powers-Samas
Powers-Samas
Powers-Samas was a British company which sold unit record equipment. The company was in competition with the British Tabulating Machine Company , with which it eventually merged in 1959 to form International Computers and Tabulators...
. In 1963 it also added the business computer divisions of Ferranti
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. Known primarily for defence electronics, the Company was once a constituent of the FTSE 100 Index but ceased trading in 1993.The...
. It exported computers to many countries around the world and went on to become part of International Computers Limited (ICL).
Products
The ICT 1101 was known as the EMIDEC 1100EMIDEC 1100
-External links:**...
computer before the acquisition of the EMI
EMI
The EMI Group, also known as EMI Music or simply EMI, is a multinational music company headquartered in London, United Kingdom. It is the fourth-largest business group and family of record labels in the recording industry and one of the "big four" record companies. EMI Group also has a major...
Computing Services Division who designed and produced it.
The ICT 1201 computer used thermionic valve
Vacuum tube
In electronics, a vacuum tube, electron tube , or thermionic valve , reduced to simply "tube" or "valve" in everyday parlance, is a device that relies on the flow of electric current through a vacuum...
technology and its main memory was drum storage
Drum memory
Drum memory is a magnetic data storage device and was an early form of computer memory widely used in the 1950s and into the 1960s, invented by Gustav Tauschek in 1932 in Austria....
. Input was from 80-column punched card
Punched card
A punched card, punch card, IBM card, or Hollerith card is a piece of stiff paper that contains digital information represented by the presence or absence of holes in predefined positions...
s and output was to 80-column cards and a printer
Line printer
The line printer is a form of high speed impact printer in which one line of type is printed at a time. They are mostly associated with the early days of computing, but the technology is still in use...
. Before the merger, under BTM, this had been known as the HEC4 (Hollerith
Herman Hollerith
Herman Hollerith was an American statistician who developed a mechanical tabulator based on punched cards to rapidly tabulate statistics from millions of pieces of data. He was the founder of one of the companies that later merged and became IBM.-Personal life:Hollerith was born in Buffalo, New...
Electronic Computer, fourth version).
The ICT 1301
ICT 1301
The ICT 1301 and its smaller derivative ICT 1300 were early business computers from International Computers and Tabulators. Typical of mid-sized machines of the era they used core memory, drum storage and punched cards, but they were unusual in that they were based on decimal logic instead of...
, and its smaller cousin the ICT 1300, used germanium
Germanium
Germanium is a chemical element with the symbol Ge and atomic number 32. It is a lustrous, hard, grayish-white metalloid in the carbon group, chemically similar to its group neighbors tin and silicon. The isolated element is a semiconductor, with an appearance most similar to elemental silicon....
transistor
Transistor
A transistor is a semiconductor device used to amplify and switch electronic signals and power. It is composed of a semiconductor material with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current...
s and core memory
Magnetic core memory
Magnetic-core memory was the predominant form of random-access computer memory for 20 years . It uses tiny magnetic toroids , the cores, through which wires are threaded to write and read information. Each core represents one bit of information...
. Backing store
Mass storage
In computing, mass storage refers to the storage of large amounts of data in a persisting and machine-readable fashion. Devices and/or systems that have been described as mass storage include tape libraries, RAID systems, hard disk drives, magnetic tape drives, optical disc drives, magneto-optical...
was magnetic drum
Drum memory
Drum memory is a magnetic data storage device and was an early form of computer memory widely used in the 1950s and into the 1960s, invented by Gustav Tauschek in 1932 in Austria....
, and optionally one-inch-, half-inch- or quarter-inch-wide magnetic tape
Magnetic tape data storage
Magnetic tape data storage uses digital recording on to magnetic tape to store digital information. Modern magnetic tape is most commonly packaged in cartridges and cassettes. The device that performs actual writing or reading of data is a tape drive...
. Input was from 80-column punched cards and optionally 160-column punched cards and punched paper tape
Punched tape
Punched tape or paper tape is an obsolete form of data storage, consisting of a long strip of paper in which holes are punched to store data...
. Output was to 80-column punched cards, printer and optionally to punched paper tape. The first customer delivery was in 1962, a 1301 sold to the University of London
University of London
-20th century:Shortly after 6 Burlington Gardens was vacated, the University went through a period of rapid expansion. Bedford College, Royal Holloway and the London School of Economics all joined in 1900, Regent's Park College, which had affiliated in 1841 became an official divinity school of the...
. One of their main attractions was that they performed British currency calculations (pounds, shillings and pence
£sd
£sd was the popular name for the pre-decimal currencies used in the Kingdom of England, later the United Kingdom, and ultimately in much of the British Empire...
) in hardware. They also had the advantage of programmers not having to learn binary
Binary numeral system
The binary numeral system, or base-2 number system, represents numeric values using two symbols, 0 and 1. More specifically, the usual base-2 system is a positional notation with a radix of 2...
or octal
Octal
The octal numeral system, or oct for short, is the base-8 number system, and uses the digits 0 to 7. Numerals can be made from binary numerals by grouping consecutive binary digits into groups of three...
arithmetic as the instruction set
Instruction set
An instruction set, or instruction set architecture , is the part of the computer architecture related to programming, including the native data types, instructions, registers, addressing modes, memory architecture, interrupt and exception handling, and external I/O...
was pure decimal and the arithmetic unit
Arithmetic logic unit
In computing, an arithmetic logic unit is a digital circuit that performs arithmetic and logical operations.The ALU is a fundamental building block of the central processing unit of a computer, and even the simplest microprocessors contain one for purposes such as maintaining timers...
had no binary mode, only decimal or pounds, shillings and pence. Its clock
Clock signal
In electronics and especially synchronous digital circuits, a clock signal is a particular type of signal that oscillates between a high and a low state and is utilized like a metronome to coordinate actions of circuits...
ran at 1 MHz. The London University machine still exists (January 2006) and is being reinstated to working condition by a group of enthusiasts.
The ICT 1302 used similar technology to the 1300/1301 but was a multiprogramming
Computer multitasking
In computing, multitasking is a method where multiple tasks, also known as processes, share common processing resources such as a CPU. In the case of a computer with a single CPU, only one task is said to be running at any point in time, meaning that the CPU is actively executing instructions for...
system capable of running three programs in addition to the Executive
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
. It also used the 'Standard Interface' for the connection of peripheral
Peripheral
A peripheral is a device attached to a host computer, but not part of it, and is more or less dependent on the host. It expands the host's capabilities, but does not form part of the core computer architecture....
s allowing much more flexibility in peripheral configuration. The 'Standard Interface' was originally prototyped on the 1301 and went on to be used on the 1900 series.
The ICT 1500 series was a design bought in from the RCA Corporation
RCA
RCA Corporation, founded as the Radio Corporation of America, was an American electronics company in existence from 1919 to 1986. The RCA trademark is currently owned by the French conglomerate Technicolor SA through RCA Trademark Management S.A., a company owned by Technicolor...
, who called it the RCA 301. RCA also sold the design to Siemens
Siemens AG
Siemens AG is a German multinational conglomerate company headquartered in Munich, Germany. It is the largest Europe-based electronics and electrical engineering company....
in Germany and Compagnie des Machines Bull
Groupe Bull
-External links:* * — Friends, co-workers and former employees of Bull and Honeywell* *...
in France who called it the Gamma 30. It used a 6 bit byte
Byte
The byte is a unit of digital information in computing and telecommunications that most commonly consists of eight bits. Historically, a byte was the number of bits used to encode a single character of text in a computer and for this reason it is the basic addressable element in many computer...
and had core stores of 10,000, 20,000 or 40,000 bytes.
The ICT 1900 series
ICT 1900 series
ICT 1900 was the name given to a series of mainframe computers released by International Computers and Tabulators and later International Computers Limited during the 1960s and '70s...
was devised after the acquisition of Ferranti's assets which brought in the new Ferranti-Packard 6000
Ferranti-Packard 6000
The FP-6000 was a second generation mainframe computer developed and built by Ferranti-Packard in the early 1960s. It is particularly notable for supporting multitasking, being one of the first commercial machines to do so...
machine from Ferranti's Canadian
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
subsidiary, which was considerably more advanced than the existing 130x line. It was decided to adapt this machine to use the 'Standard Interface', and it was put on the market as the ICT 1904
ICT 1900 series
ICT 1900 was the name given to a series of mainframe computers released by International Computers and Tabulators and later International Computers Limited during the 1960s and '70s...
, the first in a range of upward-compatible computer systems.
In 1968 ICT merged with English Electric Computers, itself formed from the prior mergers of English Electric Leo Marconi (EELM) and Elliott Automation. The resulting company became International Computers Limited (ICL). At the time of the merger English Electric Computers was in the process of making a line of large IBM System/360-compatible mainframes based on the RCA Spectra 70
RCA Spectra 70
The RCA Spectra 70 was a line of electronic data processing equipment manufactured by the Radio Corporation of America’s computer division beginning in April 1965...
, which was sold as the ICL System-4. Both 1900 and System-4 were eventually replaced by the ICL 2900 Series
ICL 2900 Series
The ICL 2900 Series was a range of mainframe computer systems announced by the UK manufacturer ICL on 9 October 1974. The company had started development, under the name "New Range" immediately on its formation in 1968...
which was introduced in 1974.
External links
- Oral history interview with Arthur L. C. Humphreys, Charles Babbage InstituteCharles Babbage InstituteThe Charles Babbage Institute is a research center at the University of Minnesota specializing in the history of information technology, particularly the history since 1935 of digital computing, programming/software, and computer networking....
, University of Minnesota. Humphreys, a former managing director of ICL, reviews the history of the British computer industry, including the merger in 1959 of British TabulatingBritish Tabulating Machine CompanyThe British Tabulating Machine Company was a firm which manufactured and sold Hollerith unit record equipment and other data-processing equipment...
and the Powers SamasPowers-SamasPowers-Samas was a British company which sold unit record equipment. The company was in competition with the British Tabulating Machine Company , with which it eventually merged in 1959 to form International Computers and Tabulators...
companies into International Computers and Tabulators, Ltd. (ICT), and the merger in 1968 of English Electric Computers Limited and ICT into ICL. - Boards from the ICT 1301
- ICT 1301 Resurrection Project
- Two articles on the HEC4 at Morgan Crucible Co