ICT 1900 series
Encyclopedia
ICT 1900 was the name given to a series of mainframe computer
s released by International Computers and Tabulators
(ICT) and later International Computers Limited (ICL) during the 1960s and '70s. The 1900 series was notable for being one of the few non-American competitors to the IBM
System/360
, enjoying significant success in the European and Commonwealth
markets.
. In order to sweeten the deal Ferranti demonstrated the Ferranti-Packard 6000
(FP6000) machine, developed by its Canadian subsidiary Ferranti-Packard
to ICT.
The FP6000 was considered advanced for the day, notably including hardware support for multiprogramming
. ICT considered using the FP6000 as their medium-sized processor in the 1965–1968 timeframe, replacing the ICT 1302
. Another plan being considered was to license a new range of machines being developed by RCA
, probably compatible with the expected IBM 8000
.
On 7 April 1964 IBM announced the System/360
series, a family of compatible machines spanning nearly the complete range of customer needs. It was immediately obvious that ICT would need a coherent response. Two paths were available: develop a range of machines based on the FP6000, using the flexibility of its design to produce smaller or larger machines, or cooperate with RCA who were re-targeting their development to a System/360 compatible range to be known as the RCA Spectra 70
.
One major consideration was that the FP6000 was already running and it was expected that a range could be developed rapidly from the FP6000, while the RCA Spectra range would take some years to become available. In the end the decision was made to go with a range of machines based on the FP6000. The centre piece of the new range was the ICT 1904, a version of the FP6000 with the ICT standard peripheral interface. For higher-end machines a new larger processor, the ICT 1906, was to be developed by the ICT West Gorton unit (formerly part of Ferranti). To meet the needs of smaller customers smaller machines, the ICT 1901 and ICT 1902/3 were developed by the ICT Stevenage
unit, based on the PF182 and PF183 processors already in development.
On 29 September 1964 the ICT 1900 range was announced in a filmed presentation, scripted by Anthony Jay. The following week two working systems were demonstrated at the Business Equipment Exhibition, Olympia
.
The first commercial sale was made in 1964 to the Morgan Crucible Company
and consisted of a 16K word 1902 with an 80-column 980-card/minute reader, a card punch, a 600 line/min printer and 4 x 20kb/s tape drives. It was soon upgraded to a 32K word memory and a floating point unit to allow for some scientific work. The same company had also been the first to order ICT's first computer, the HEC4 (later ICT 1201), in 1955.
The first system delivered was a 1904, for the Northampton College of Advanced Technology, London in January 1965.
to memory architecture with eight accumulator registers. Three of the accumulators could be used as modifier (Index
) registers. The word length was 24 bits
, which could be used as four 6 bit characters. Two instructions were provided for copying single characters to and from memory.
The accumulators were addressable as if they were the first eight words of memory, giving the effect of register to register instructions with no extra operation codes being needed. In fact the hardware registers were an optional feature and if not fitted the accumulators were the first eight words of memory. The large number of optional features in the FP6000 design gave ICT great flexibility in pricing,
A notable features of the series was the hardware support for running multiple processes – every process ran in an independent address space, enforced by datum and limit registers. No user process could access the memory of any other process. Later models added paging
hardware, allowing true virtual memory
with the GEORGE 4
operating system.
On the original models the address size was 15 bits, allowing up to 32Kwords of memory. Later models added 22 bit addressing, allowing a theoretical 4Mword maximum memory. Instructions contained a 12 bit operand, either fixed or offset from an index register. Branch instructions held a 15 bit offset, allowing access to all memory on the initial range. When the address size was increased to 22 bits replaced (indirect
) and relative branches were added to the instruction set to allow access to the larger address space.
The largest change between the original FP6000 and the 1900 series was the inclusion of the ICT standard interface for connection of peripherals. This allowed connection of any ICT peripheral to any processor of the series, and users could upgrade their processors while keeping the same peripherals or vice-versa.
All I/O operations were performed by a privileged supervisor process, known as the executive. User processes communicated with executive using extracodes, instructions that caused a trap
into the executive when run.
On smaller members of the series some expensive instructions (floating point
for example) were also implemented as extracodes. The combination of the executive and hardware provided the same interface to programs running on any model of the range.
The hardware floating point unit, if fitted, ran autonomously. When a floating point operation was started integer instructions could be run in parallel until the result of the floating point operation was needed.
In order to deal with data on paper tape
or from communications equipment a system of shifts could be used to represent the full 128 characters of ASCII
.
Character #74 (octal
74) was considered an alpha shift and indicated subsequent characters were to be considered upper case, #75 was a beta shift and indicated subsequent characters were in lower case, #75 the delta shift, indicating the next character was a control character and #77 used as a fill (ignore) character.
For example the ASCII string "Hello World" would be encoded as "
The 1900 used a modification of an early version of ASCII, known by ICT as the ECMA
character set, with some characters in different positions:
Comparison with System/360
Both the 1900 series and System/360 provided hardware support for multi-programming. On the 1900 all user memory addresses were modified by a datum (base address) register and checked against a limit register, thus preventing one program interfering with an other. The System/360 gave each process and every 2048 byte block of memory a 4 bit key. If a process key did not match the memory block key an exception would result. The 1900 system had the disadvantage that it required that programs occupy a contiguous area of memory but allowed processes to be relocated during execution, simplifying the work of the operating system. The 1900 system also allowed any process direct access to the first 4096 words of its address space. (Both the 1900 and 360 had a 12 bit operand field, but on the 360 addresses were physical addresses so a program could directly access the first 4096 bytes of physical memory, which was unlikely to be useful).
The System/360 had the advantage of a larger word and character size, its 32-bit words were large enough for (low accuracy) floating point numbers where the 1900 needed at least two words. The 8-bit byte of the System/360 allowed manipulation of lower case characters without the complex shift sequences of the 1900. However in the early days the smaller word size of the 1900 was seen as a cost advantage, as the memory could be 25 per cent cheaper for the same number of words.
The execution time for an addition instruction ("add the contents of store location x to register y") ranged from 2.5 μs for a 1906 or 1907 with 1.1 μs core store, to 34 μs for a 1901 with 6 μs core store.
All machines apart from the low end 1901 were operated from an modified Teletype
Model 33 ASR used to give commands to the executive. The 1901 was operated from console switches, a console was available as an optional extra.
A range of peripherals was available, including 80-column card
punches and readers, 8 track paper tape punches and readers and solid barrel line printer
s. Data could be stored on half-inch magnetic tape
. Magnetic disk storage became available in 1966.
Improvements to the memory subsystems of these machines, replacing the 1.8µs core with 0.75µs core, were introduced as the F series.
(ICT merged with English Electric Computers to form ICL on 9 July 1968. Thus although the E series had been designed by ICT many, if not all, were delivered with ICL badges).
replacing the remaining machines from initial series and the E/F machines. The original discrete germanium semiconductor implementations were replaced by Texas Instruments
7400 series TTL
integrated circuits in most of the range and Motorola
MECL 10K ECL
integrated circuits in the new 1906A (which was based on the original 1906 rather than the dual processor 1904 of the 1906E/F). There was a proposal to build a multiprocessor version of the 1906A, the 1908A (known internally as Project 51), which would allow ICL to compete with the large CDC and IBM machines in Universities and research centers but it was eventually abandoned in favor of accelerating work on the New Range
which was being designed to replace both the 1900 series and the ICL System 4
.
With the A series a hardware floating point unit was made an optional feature of all the machines instead of having a different model number for floating point equipped machines.
The 22-bit addressing mode and extended branch mode introduced by the 1906 was extended to the 1902A and 1903A, but not the much smaller 1901A.
ICL introduced a paging
unit to the higher end machines (1904A, 1906A) and a new version of the GEORGE
operating system, GEORGE 4 which was compatible with GEORGE 3 but used paged virtual memory in place of the simple base/limit system of the earlier machines.
nickel plated wire memory for the top of the range 1906S.
entry level machine, which began to cut into sales of the ICL 1901 and 1902 models. In order to recapture the market a project known internally as PF73 was started, based on an ICL Stevenage developed microprogrammed machine known as MICOS-1. PF73 eventually came to market in 1973 as the ICL 2903 and 2904, but despite their New Range numbering these machines used the ICL 1900 instruction set and ran 1900 software. The 2903/2904 were released with a RPG compiler to better compete with System/3
. It was a major commercial success with almost 3000 machines sold.
An EMMY processor emulating the IBM 360 order code was estimated to be around the speed of an IBM 360/50, implying that the ME29 was faster than the original ICT 1904, approaching the speed of the ICT 1906.
allowing execution of 1900 series programs.
1300 series (Odra 1304, Odra 1305 and Odra 1325) were a range of 1900 compatible machines built by Elwro
in Wrocław, Poland
between 1971 and 1978. By agreement with ICL the Odra machines ran standard ICL software (executive E6RM, George 3).
) as an emulation as well as the New Range instruction set under the newer VME (Virtual Machine Environment). Later CME (Concurrent Machine Environment) microcode
was developed, which allowed DME and VME to co-exist (and run) concurrently on the same platform, similar to the functionality offered by virtualisation software such as VMware
today.
Despite its simplicity executive was, for the time, quite powerful, allocating memory to programs as needed (rather than the fixed partitions provided by OS/360). This was possible because the FP6000 design contained hardware to aid multi-programming, datum and limit registers which made programs address independent and avoided one program accessing the memory allocated to another.
To allow more efficient use of peripherals, as well running multiple programs simultaneously, executive allowed a limited multi-threading within programs (each program could be split into up to four sub-programs, sharing the same address space, which were also time shared. While one sub-program was waiting for peripheral activity another could continue processing).
An extended version of the FP6000 executive was provided with the ICT 1904/1905, and new versions were written for the ICT 1906/7 and ICT 1901/2/3. An important task of these different versions was to hide the hardware differences between the different machines, providing emulation
of missing instructions as extracodes. The concept was that applications, and later operating systems, were written to run on the combination of the hardware and the executive, and so would run on any member of the series, no matter how different the underlying hardware was.
With the introduction of magnetic disk systems executive became more complex, using overlaying
to reduce it's memory footprint. Disk based executives included features to simplify disk operations, handling file management (creation, renaming, deletion, resizing) on behalf of user programs. Files were identified by 12 character names and a user program did not need to know which physical disk was being used for a file.
. The initial design of the new system, named George in part after George E. Felton, head of the Basic Programming Division, was based on ideas from the Orion and the spooling
system of the Atlas
computer.
The initial versions, George 1 (for the ICT 1901, 1902 and 1903 machines) was a simple batch processing
system. Job descriptions were read in from cards
or paper tape
, peripherals and magnetic tape files were dynamically allocated to the job which was then run, producing output on the line printer.
George 2 added the concept of spooling
. Jobs and input data were read in from cards or paper tape to an input well on disk or tape. The jobs are then run, writing output to on disk or tape spool files, which are then written to the output peripherals. The input/processing/output stages were run in parallel, increasing machine utilisation. On larger machines it was possible to run multiple jobs simultaneously.
George 1 and 2 ran as simple programs under executive (with trusted status that allowed them to control user programs). George 3 was a complete operating system in itself, it used a much reduced executive responsible only for handling low level hardware access. George 3 implemented both batch processing and Multiple online programming (MOP) – interactive use from terminals.
George 4 was introduced with the availability of paging
hardware on the later machines and implemented paged virtual memory
instead of the simple swapping used by George 3.
and later the big three, ALGOL 60
, COBOL
and FORTRAN 66.
The compilers were released in various versions, of increasing sophistication. Initially paper tape and cards were used for input and output, later magnetic tape and finally disk files.
The first versions of the compilers ran in very limited space, starting around 4K words for PLAN and NICOL and as little as 16K words for FORTRAN and ALGOL. Later versions for the George 3 and 4 operating systems expanded to sizes as large as 48K words.
Other languages available included:
Mainframe computer
Mainframes are powerful computers used primarily by corporate and governmental organizations for critical applications, bulk data processing such as census, industry and consumer statistics, enterprise resource planning, and financial transaction processing.The term originally referred to the...
s released by International Computers and Tabulators
International Computers and Tabulators
International Computers and Tabulators or ICT was formed in 1959 by a merger of the British Tabulating Machine Company and Powers-Samas. In 1963 it also added the business computer divisions of Ferranti...
(ICT) and later International Computers Limited (ICL) during the 1960s and '70s. The 1900 series was notable for being one of the few non-American competitors to the IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
System/360
System/360
The IBM System/360 was a mainframe computer system family first announced by IBM on April 7, 1964, and sold between 1964 and 1978. It was the first family of computers designed to cover the complete range of applications, from small to large, both commercial and scientific...
, enjoying significant success in the European and Commonwealth
Commonwealth of Nations
The Commonwealth of Nations, normally referred to as the Commonwealth and formerly known as the British Commonwealth, is an intergovernmental organisation of fifty-four independent member states...
markets.
Creation of the ICT 1900 series
In early 1963 ICT was in negotiations to buy the computer business of FerrantiFerranti
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...
. In order to sweeten the deal Ferranti demonstrated the 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...
(FP6000) machine, developed by its Canadian subsidiary Ferranti-Packard
Ferranti-Packard
Ferranti-Packard Ltd. was the Canadian division of Ferranti's global manufacturing empire, formed by the 1958 merger of Ferranti Electric and Packard Electric...
to ICT.
The FP6000 was considered advanced for the day, notably including hardware support for multiprogramming
Multiprogramming
Computer multiprogramming is the allocation of a computer system and its resources to more than one concurrent application, job or user ....
. ICT considered using the FP6000 as their medium-sized processor in the 1965–1968 timeframe, replacing the ICT 1302
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...
. Another plan being considered was to license a new range of machines being developed by RCA
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...
, probably compatible with the expected IBM 8000
IBM 8000
The IBM 8000 series was an ill-fated transistor-based successor to the IBM 7000 series. Important engineers on the project included Fred Brooks and Gerry Blaauw. Despite some technical successes, the project became a political football, amid IBM's search for a unified product line...
.
On 7 April 1964 IBM announced the System/360
System/360
The IBM System/360 was a mainframe computer system family first announced by IBM on April 7, 1964, and sold between 1964 and 1978. It was the first family of computers designed to cover the complete range of applications, from small to large, both commercial and scientific...
series, a family of compatible machines spanning nearly the complete range of customer needs. It was immediately obvious that ICT would need a coherent response. Two paths were available: develop a range of machines based on the FP6000, using the flexibility of its design to produce smaller or larger machines, or cooperate with RCA who were re-targeting their development to a System/360 compatible range to be known as 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...
.
One major consideration was that the FP6000 was already running and it was expected that a range could be developed rapidly from the FP6000, while the RCA Spectra range would take some years to become available. In the end the decision was made to go with a range of machines based on the FP6000. The centre piece of the new range was the ICT 1904, a version of the FP6000 with the ICT standard peripheral interface. For higher-end machines a new larger processor, the ICT 1906, was to be developed by the ICT West Gorton unit (formerly part of Ferranti). To meet the needs of smaller customers smaller machines, the ICT 1901 and ICT 1902/3 were developed by the ICT Stevenage
Stevenage
Stevenage is a town and borough in Hertfordshire, England. It is situated to the east of junctions 7 and 8 of the A1, and is between Letchworth Garden City to the north, and Welwyn Garden City to the south....
unit, based on the PF182 and PF183 processors already in development.
On 29 September 1964 the ICT 1900 range was announced in a filmed presentation, scripted by Anthony Jay. The following week two working systems were demonstrated at the Business Equipment Exhibition, Olympia
Olympia, London
Olympia is an exhibition centre and conference centre in West Kensington, on the boundary between The Royal Borough of Kensington & Chelsea and Hammersmith & Fulham, London, W14 8UX, England. It opened in the 19th century and was originally known as the National Agricultural Hall.Opened in 1886,...
.
The first commercial sale was made in 1964 to the Morgan Crucible Company
Morgan Crucible
The Morgan Crucible is one of the largest UK manufacturers of carbon and ceramic products for industrial use. It is a constituent of the FTSE 250 index.-History:...
and consisted of a 16K word 1902 with an 80-column 980-card/minute reader, a card punch, a 600 line/min printer and 4 x 20kb/s tape drives. It was soon upgraded to a 32K word memory and a floating point unit to allow for some scientific work. The same company had also been the first to order ICT's first computer, the HEC4 (later ICT 1201), in 1955.
The first system delivered was a 1904, for the Northampton College of Advanced Technology, London in January 1965.
Architecture of the 1900 series
The ICT 1900 was a word addressing machine using a registerProcessor register
In computer architecture, a processor register is a small amount of storage available as part of a CPU or other digital processor. Such registers are addressed by mechanisms other than main memory and can be accessed more quickly...
to memory architecture with eight accumulator registers. Three of the accumulators could be used as modifier (Index
Index register
An index registerCommonly known as a B-line in early British computers. in a computer's CPU is a processor register used for modifying operand addresses during the run of a program, typically for doing vector/array operations...
) registers. The word length was 24 bits
24-bit
Notable 24-bit machines include the ICT 1900 series and the Harris H series.The IBM System/360, announced in 1964, was a popular computer system with 24-bit addressing and 32-bit general registers and arithmetic...
, which could be used as four 6 bit characters. Two instructions were provided for copying single characters to and from memory.
The accumulators were addressable as if they were the first eight words of memory, giving the effect of register to register instructions with no extra operation codes being needed. In fact the hardware registers were an optional feature and if not fitted the accumulators were the first eight words of memory. The large number of optional features in the FP6000 design gave ICT great flexibility in pricing,
A notable features of the series was the hardware support for running multiple processes – every process ran in an independent address space, enforced by datum and limit registers. No user process could access the memory of any other process. Later models added paging
Paging
In computer operating systems, paging is one of the memory-management schemes by which a computer can store and retrieve data from secondary storage for use in main memory. In the paging memory-management scheme, the operating system retrieves data from secondary storage in same-size blocks called...
hardware, allowing true virtual memory
Virtual memory
In computing, virtual memory is a memory management technique developed for multitasking kernels. This technique virtualizes a computer architecture's various forms of computer data storage , allowing a program to be designed as though there is only one kind of memory, "virtual" memory, which...
with the GEORGE 4
GEORGE (operating system)
GEORGE was the name given to a series of operating systems released by International Computers and Tabulators in the 1960s, for the ICT 1900 series of computers....
operating system.
On the original models the address size was 15 bits, allowing up to 32Kwords of memory. Later models added 22 bit addressing, allowing a theoretical 4Mword maximum memory. Instructions contained a 12 bit operand, either fixed or offset from an index register. Branch instructions held a 15 bit offset, allowing access to all memory on the initial range. When the address size was increased to 22 bits replaced (indirect
Indirect branch
An indirect branch is a type of program control instruction present in some machine language instruction sets. Rather than specifying the address of the next instruction to execute, as in a direct branch, the argument specifies where the address is located...
) and relative branches were added to the instruction set to allow access to the larger address space.
The largest change between the original FP6000 and the 1900 series was the inclusion of the ICT standard interface for connection of peripherals. This allowed connection of any ICT peripheral to any processor of the series, and users could upgrade their processors while keeping the same peripherals or vice-versa.
All I/O operations were performed by a privileged supervisor process, known as the executive. User processes communicated with executive using extracodes, instructions that caused a trap
Trap (computing)
In computing and operating systems, a trap, also known as an exception or a fault, is typicallyThere is a wide variation in the nomenclature...
into the executive when run.
On smaller members of the series some expensive instructions (floating point
Floating point
In computing, floating point describes a method of representing real numbers in a way that can support a wide range of values. Numbers are, in general, represented approximately to a fixed number of significant digits and scaled using an exponent. The base for the scaling is normally 2, 10 or 16...
for example) were also implemented as extracodes. The combination of the executive and hardware provided the same interface to programs running on any model of the range.
The hardware floating point unit, if fitted, ran autonomously. When a floating point operation was started integer instructions could be run in parallel until the result of the floating point operation was needed.
Data formats
The instruction set supported the following data formats:- Character form
- A 24-bit word could hold four 6-bit characters.
- Counter modifier, also known as an index word
- A 9-bit counter and a 15-bit modifier (address) field. A loop instruction decremented the counter and incremented the address either by 1 or 2.
- This format was only available in 15 bit addressing mode. In 22 bit mode the counter and address were kept in separate words.
- Character counter modifier, also known as a character index word
- 2-bit character offset, 7-bit counter and 15-bit modifier (word address). The BCHX (branch on character indexing) instruction decremented the counter and incremented the character offset, incrementing the word address if the character offset overflowed, branching if the count had not reached zero.
- In 22 bit addressing mode the counter was unavailable, the format was a 2-bit character offset and a 22 bit word address, the BCHX instruction incremented the character offset, incremented the word address if the character offset overflowed, and branched unconditionally.
- Single-length integer
- A 24-bit two's complementTwo's complementThe two's complement of a binary number is defined as the value obtained by subtracting the number from a large power of two...
signed number.
- A 24-bit two's complement
- Multi-length integer
- The first word held a 24 bit two's complement signed number, subsequent words held 23 bit extensions with the high bit used for internal carry.
- Single-length floating pointFloating pointIn computing, floating point describes a method of representing real numbers in a way that can support a wide range of values. Numbers are, in general, represented approximately to a fixed number of significant digits and scaled using an exponent. The base for the scaling is normally 2, 10 or 16...
number- Two words holding a 24-bit signed argument (mantissaSignificandThe significand is part of a floating-point number, consisting of its significant digits. Depending on the interpretation of the exponent, the significand may represent an integer or a fraction.-Examples:...
) and a 9-bit exponent.
- Two words holding a 24-bit signed argument (mantissa
- Double-length floating-point number
- Two words holding a 38-bit signed argument and a 9-bit exponent.
- Quadruple-length floating-point number
- Four words holding a 75-bit signed argument and a 9-bit exponent.
- Handled in software on all but 1906/7 processors with the extended floating point feature.
Character set
Since the ICT 1900 used a 6 bit character it was largely limited to a 64 character repertoire, with only upper case letters and no control characters.In order to deal with data on 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...
or from communications equipment a system of shifts could be used to represent the full 128 characters of ASCII
ASCII
The American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...
.
Character #74 (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...
74) was considered an alpha shift and indicated subsequent characters were to be considered upper case, #75 was a beta shift and indicated subsequent characters were in lower case, #75 the delta shift, indicating the next character was a control character and #77 used as a fill (ignore) character.
For example the ASCII string "Hello World" would be encoded as "
αHβELLO αWβORLD".The 1900 used a modification of an early version of ASCII, known by ICT as the ECMA
Ecma International
Ecma International is an international, private non-profit standards organization for information and communication systems. It acquired its name in 1994, when the European Computer Manufacturers Association changed its name to reflect the organization's global reach and activities...
character set, with some characters in different positions:
| ASCII | $ |
\ |
^ |
_ |
` |
| ECMA | £ |
$ |
↑ |
← |
_ |
Comparison with System/360System/360The IBM System/360 was a mainframe computer system family first announced by IBM on April 7, 1964, and sold between 1964 and 1978. It was the first family of computers designed to cover the complete range of applications, from small to large, both commercial and scientific...
Both the 1900 series and System/360 provided hardware support for multi-programming. On the 1900 all user memory addresses were modified by a datum (base address) register and checked against a limit register, thus preventing one program interfering with an other. The System/360 gave each process and every 2048 byte block of memory a 4 bit key. If a process key did not match the memory block key an exception would result. The 1900 system had the disadvantage that it required that programs occupy a contiguous area of memory but allowed processes to be relocated during execution, simplifying the work of the operating system. The 1900 system also allowed any process direct access to the first 4096 words of its address space. (Both the 1900 and 360 had a 12 bit operand field, but on the 360 addresses were physical addresses so a program could directly access the first 4096 bytes of physical memory, which was unlikely to be useful).The System/360 had the advantage of a larger word and character size, its 32-bit words were large enough for (low accuracy) floating point numbers where the 1900 needed at least two words. The 8-bit byte of the System/360 allowed manipulation of lower case characters without the complex shift sequences of the 1900. However in the early days the smaller word size of the 1900 was seen as a cost advantage, as the memory could be 25 per cent cheaper for the same number of words.
Initial range
The initial range of machines was:- ICT 1901
- A very small machine, with a 6-bit wide mill (arithmetic unitArithmetic logic unitIn 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...
), it was still compatible with the other machines, a 24-bit operation would be performed by the processor as four 6-bit operations. Based on the ICT Stevenage developed PF183. The 1901 was announced and released after the other members of the initial range, in response to the IBM 360/20, and was a great success.
- A very small machine, with a 6-bit wide mill (arithmetic unit
- ICT 1902
- A small machine. Based on the ICT Stevenage PF182 processor.
- Like the 1901 the 1902 performed multiply and divide operations as extracodes. An optional commercial computing facility or CCF was available to add hardware multiply and divide. An optional floating point unit, the scientific computing facility, SCF was also available (as a super-set of the CCF).
- ICT 1903
- The same processor as the 1902, but with 2µs core in place of the 6µs core supplied with the 1902.
- ICT 1904
- The ICT West Gorton processor derived from the FP6000 with the addition of the ICT standard interface.
- ICT 1905
- A 1904 with an autonomous hardware floating point unit.
- ICT 1906
- A new processor designed by ICT West Gorton with a 48-bit wide memory pathway and a 22-bit addressing mode. Delivered with up to 256Kwords of memory.
- ICT 1907
- A 1906 with a floating point unit
- ICT 1909
- A machine similar to the 1905 but with a slow 6µs store comparable to the 1902. A special product designed for Universities who needed floating point found the 1905 too expensive.
The execution time for an addition instruction ("add the contents of store location x to register y") ranged from 2.5 μs for a 1906 or 1907 with 1.1 μs core store, to 34 μs for a 1901 with 6 μs core store.
All machines apart from the low end 1901 were operated from an modified Teletype
Teletype Corporation
The Teletype Corporation, a part of American Telephone and Telegraph Company's Western Electric manufacturing arm since 1930, came into being in 1928 when the Morkrum-Kleinschmidt Company changed its name to the name of its trademark equipment...
Model 33 ASR used to give commands to the executive. The 1901 was operated from console switches, a console was available as an optional extra.
A range of peripherals was available, including 80-column 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...
punches and readers, 8 track paper tape punches and readers and solid barrel line 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...
s. Data could be stored on half-inch magnetic tape
Magnetic tape
Magnetic tape is a medium for magnetic recording, made of a thin magnetizable coating on a long, narrow strip of plastic. It was developed in Germany, based on magnetic wire recording. Devices that record and play back audio and video using magnetic tape are tape recorders and video tape recorders...
. Magnetic disk storage became available in 1966.
The 1900 E/F series
In 1968 ICT introduced the E series machines:- ICT 1904E
- Some improvements were made to the original 1904 and the new 22-bit addressing mode developed for the 1906 was made available.
- ICT 1905E
- The 1904E with a floating point unit.
- ICT 1906E
- The original 1906 had not been as fast as hoped, therefore the new top of the range machines were actually dual-processor versions of the 1904E.
- ICT 1907E
- A 1906E with a special higher performance floating point unit.
Improvements to the memory subsystems of these machines, replacing the 1.8µs core with 0.75µs core, were introduced as the F series.
(ICT merged with English Electric Computers to form ICL on 9 July 1968. Thus although the E series had been designed by ICT many, if not all, were delivered with ICL badges).
1900 A series
In 1969 the 1900 A series was delivered,replacing the remaining machines from initial series and the E/F machines. The original discrete germanium semiconductor implementations were replaced by Texas Instruments
Texas Instruments
Texas Instruments Inc. , widely known as TI, is an American company based in Dallas, Texas, United States, which develops and commercializes semiconductor and computer technology...
7400 series TTL
Transistor-transistor logic
Transistor–transistor logic is a class of digital circuits built from bipolar junction transistors and resistors. It is called transistor–transistor logic because both the logic gating function and the amplifying function are performed by transistors .TTL is notable for being a widespread...
integrated circuits in most of the range and Motorola
Motorola
Motorola, Inc. was an American multinational telecommunications company based in Schaumburg, Illinois, which was eventually divided into two independent public companies, Motorola Mobility and Motorola Solutions on January 4, 2011, after losing $4.3 billion from 2007 to 2009...
MECL 10K ECL
Emitter-coupled logic
In electronics, emitter-coupled logic , is a logic family that achieves high speed by using an overdriven BJT differential amplifier with single-ended input, whose emitter current is limited to avoid the slow saturation region of transistor operation....
integrated circuits in the new 1906A (which was based on the original 1906 rather than the dual processor 1904 of the 1906E/F). There was a proposal to build a multiprocessor version of the 1906A, the 1908A (known internally as Project 51), which would allow ICL to compete with the large CDC and IBM machines in Universities and research centers but it was eventually abandoned in favor of accelerating work on the New Range
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 being designed to replace both the 1900 series and the ICL System 4
English Electric System 4
The English Electric System 4 was a mainframe computer introduced in the mid-1960s. It was derived from the RCA Spectra 70 range, itself a clone of the IBM System 360 range. The models in the range included the System 4-10, 4-30, 4-50 , 4-70 and 4-75. ICL documentation also mentions a model 4-40...
.
With the A series a hardware floating point unit was made an optional feature of all the machines instead of having a different model number for floating point equipped machines.
The 22-bit addressing mode and extended branch mode introduced by the 1906 was extended to the 1902A and 1903A, but not the much smaller 1901A.
ICL introduced a paging
Paging
In computer operating systems, paging is one of the memory-management schemes by which a computer can store and retrieve data from secondary storage for use in main memory. In the paging memory-management scheme, the operating system retrieves data from secondary storage in same-size blocks called...
unit to the higher end machines (1904A, 1906A) and a new version of the GEORGE
GEORGE (operating system)
GEORGE was the name given to a series of operating systems released by International Computers and Tabulators in the 1960s, for the ICT 1900 series of computers....
operating system, GEORGE 4 which was compatible with GEORGE 3 but used paged virtual memory in place of the simple base/limit system of the earlier machines.
- ICL 1901A
- Deliveries started in 1969
- ICL 1902A
- Deliveries started in 1969
- ICL 1903A
- Deliveries started in 1969
- ICL 1904A
- First deliveries in 1970.
- The 1904A had an optional paging unit and so could run GEORGE 4
- ICL 1906A
- First deliveries in 1970
- The 1906A had a paging unit and so could run GEORGE 4
The 1900 S series
In April 1971 ICL announced the S series of machines, replacing the core store of the earlier machines with semiconductor memory in most of the range and very fast PlesseyPlessey
The Plessey Company plc was a British-based international electronics, defence and telecommunications company. It originated in 1917, growing and diversifying into electronics. It expanded after the second world war by acquisition of companies and formed overseas companies...
nickel plated wire memory for the top of the range 1906S.
- ICL 1901S
- 4µs semiconductor store
- ICL 1902S
- 3µs semiconductor store
- ICL 1903S
- 1.5µs semiconductor store
- ICL 1904S
- First delivery in 1972. New SchottkySchottky transistorA Schottky transistor is a combination of a transistor and a Schottky diode that prevents the transistor from saturating by diverting the excessive input current. It is also called a Schottky-clamped transistor.-Mechanism:...
STTL logic used, giving a 30% performance increase. 500ns semiconductor store.
- First delivery in 1972. New Schottky
- ICL 1906S
- First delivery in 1973. Nickel plated wire memory with a 250ns cycle speed.
1900 T series
As the larger models of the new range were being introduced it was decided that the lower models of the 1900 range were becoming uncompetitive. To refresh the range new models were released. In each case the model was simply based on the next higher model of the previous range, the 1903T was based on the 1904S for example.- ICL 1901T
- Delivery started in 1974. The 1901T was based on the 1902S with an integrated disk controller and VDUBlock-oriented terminalA block-oriented terminal is a type of computer terminal that communicates with its host in blocks of data, usually chunks of text, as opposed to a character-oriented terminal that communicates with its host one character at a time...
controller added to the processor cabinet to reduce space.
- Delivery started in 1974. The 1901T was based on the 1902S with an integrated disk controller and VDU
- ICL 1902T
- Delivery started in 1974. The 1902T was based on the 1903S with an integrated disk controller and integrated VDUBlock-oriented terminalA block-oriented terminal is a type of computer terminal that communicates with its host in blocks of data, usually chunks of text, as opposed to a character-oriented terminal that communicates with its host one character at a time...
controller.
- Delivery started in 1974. The 1902T was based on the 1903S with an integrated disk controller and integrated VDU
- ICL 1903T
- Delivery started in 1973. As the 1903T was based on the 1904S it was available with a paging unit and could run George 4. The processor clock and memory cycle time were slower than the 1904S, allowing the use of cheaper parts. The 1903T was built at the ICL West Gorton site.
1900 Compatible machines
During and after the production of the 1900 series a number of compatible (or clone) machines were produced, either by ICL, licensees or competitors.The 2903/2904
In 1969 IBM had introduced the System/3System/3
The IBM System/3 was a low-end business computer aimed at new customers and organizations that still used IBM 1400 series computers or unit record equipment...
entry level machine, which began to cut into sales of the ICL 1901 and 1902 models. In order to recapture the market a project known internally as PF73 was started, based on an ICL Stevenage developed microprogrammed machine known as MICOS-1. PF73 eventually came to market in 1973 as the ICL 2903 and 2904, but despite their New Range numbering these machines used the ICL 1900 instruction set and ran 1900 software. The 2903/2904 were released with a RPG compiler to better compete with System/3
System/3
The IBM System/3 was a low-end business computer aimed at new customers and organizations that still used IBM 1400 series computers or unit record equipment...
. It was a major commercial success with almost 3000 machines sold.
The ME29
Based on a fully microprogrammed CPU, the EMMY from Palyn Associates the ME29 was sold as a replacement for the 2903 and 2904, still executing the 1900 order code.An EMMY processor emulating the IBM 360 order code was estimated to be around the speed of an IBM 360/50, implying that the ME29 was faster than the original ICT 1904, approaching the speed of the ICT 1906.
IBM 370/145
In an effort to increase sales to ICL customers, and to profit from the difficulties ICL were having moving customers from the 1900 to the New Range, IBM introduced a microcode package for the 370/145System/370
The IBM System/370 was a model range of IBM mainframes announced on June 30, 1970 as the successors to the System/360 family. The series maintained backward compatibility with the S/360, allowing an easy migration path for customers; this, plus improved performance, were the dominant themes of the...
allowing execution of 1900 series programs.
Odra 1300 series
The OdraOdra (computer)
Odra was a line of computers manufactured in Wrocław, Poland.The production started in 1959–1960. Models 1001, 1002, 1003, 1013, 1103, 1204 were of original Polish construction. Models 1304 and 1305 were functional counterparts of ICL 1905 and 1906 due to software agreement...
1300 series (Odra 1304, Odra 1305 and Odra 1325) were a range of 1900 compatible machines built by Elwro
Elwro
Elwro – was a Polish company that produced the Odra and ELWAT computers and two ZX Spectrum clones. The Elwro factory was sold to Siemens in 1993 and shut down shortly afterwards....
in Wrocław, Poland
Poland
Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...
between 1971 and 1978. By agreement with ICL the Odra machines ran standard ICL software (executive E6RM, George 3).
ICL 2900 (New Range) systems
Second generation "S3E" (microcoded) versions of the larger New Range systems (such as the 2960/2966 from West Gorton, and the later 2940/50 from Stevenage), could run 1900 series code under DME (Direct Machine EnvironmentDirect Machine Environment
Direct Machine Environment, abbreviated DME, was a mainframe environment for the ICL 2900 Series of computing systems from International Computers Limited that was developed in the 1970s...
) as an emulation as well as the New Range instruction set under the newer VME (Virtual Machine Environment). Later CME (Concurrent Machine Environment) microcode
Microcode
Microcode is a layer of hardware-level instructions and/or data structures involved in the implementation of higher level machine code instructions in many computers and other processors; it resides in special high-speed memory and translates machine instructions into sequences of detailed...
was developed, which allowed DME and VME to co-exist (and run) concurrently on the same platform, similar to the functionality offered by virtualisation software such as VMware
VMware
VMware, Inc. is a company providing virtualization software founded in 1998 and based in Palo Alto, California, USA. The company was acquired by EMC Corporation in 2004, and operates as a separate software subsidiary ....
today.
Executive
The FP6000 ran under the control of operators executive, a simple operating system that allowed the operator using the system console to load programs from magnetic tape, cards or paper tape, allocate peripherals to programs and attribute priorities to running programs. Executive performed all the I/O operations on behalf of user programs, allowing allocation of different peripherals as needed.Despite its simplicity executive was, for the time, quite powerful, allocating memory to programs as needed (rather than the fixed partitions provided by OS/360). This was possible because the FP6000 design contained hardware to aid multi-programming, datum and limit registers which made programs address independent and avoided one program accessing the memory allocated to another.
To allow more efficient use of peripherals, as well running multiple programs simultaneously, executive allowed a limited multi-threading within programs (each program could be split into up to four sub-programs, sharing the same address space, which were also time shared. While one sub-program was waiting for peripheral activity another could continue processing).
An extended version of the FP6000 executive was provided with the ICT 1904/1905, and new versions were written for the ICT 1906/7 and ICT 1901/2/3. An important task of these different versions was to hide the hardware differences between the different machines, providing emulation
Emulator
In computing, an emulator is hardware or software or both that duplicates the functions of a first computer system in a different second computer system, so that the behavior of the second system closely resembles the behavior of the first system...
of missing instructions as extracodes. The concept was that applications, and later operating systems, were written to run on the combination of the hardware and the executive, and so would run on any member of the series, no matter how different the underlying hardware was.
With the introduction of magnetic disk systems executive became more complex, using overlaying
Overlaying
Overlaying is the act of smothering a child to death by rolling over them in sleep.Overlaying was perceived to be one common way of conducting infanticide in Victorian England...
to reduce it's memory footprint. Disk based executives included features to simplify disk operations, handling file management (creation, renaming, deletion, resizing) on behalf of user programs. Files were identified by 12 character names and a user program did not need to know which physical disk was being used for a file.
GEORGE
In December 1964 ICT set up an Operating Systems Branch to develop a new operating system for the 1906/7. The branch was initially staffed with people being released by the end of work on the OMP operating system for the Ferranti OrionFerranti Orion
The Orion was a mid-range mainframe computer introduced by Ferranti in 1959 and installed for the first time in 1961. Ferranti positioned Orion to be their primary offering during the early 1960s, complementing their high-end Atlas and smaller systems like the Sirius and Argus...
. The initial design of the new system, named George in part after George E. Felton, head of the Basic Programming Division, was based on ideas from the Orion and the spooling
Spooling
In computer science, spool refers to the process of placing data in a temporary working area for another program to process. The most common use is in writing files on a magnetic tape or disk and entering them in the work queue for another process. Spooling is useful because devices access data at...
system of the Atlas
Atlas Computer (Manchester)
The Atlas Computer was a joint development between the University of Manchester, Ferranti, and Plessey. The first Atlas, installed at Manchester University and officially commissioned in 1962, was one of the world's first supercomputers, considered to be the most powerful computer in the world at...
computer.
The initial versions, George 1 (for the ICT 1901, 1902 and 1903 machines) was a simple batch processing
Batch processing
Batch processing is execution of a series of programs on a computer without manual intervention.Batch jobs are set up so they can be run to completion without manual intervention, so all input data is preselected through scripts or command-line parameters...
system. Job descriptions were read in from cards
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...
or 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...
, peripherals and magnetic tape files were dynamically allocated to the job which was then run, producing output on the line printer.
George 2 added the concept of spooling
Spooling
In computer science, spool refers to the process of placing data in a temporary working area for another program to process. The most common use is in writing files on a magnetic tape or disk and entering them in the work queue for another process. Spooling is useful because devices access data at...
. Jobs and input data were read in from cards or paper tape to an input well on disk or tape. The jobs are then run, writing output to on disk or tape spool files, which are then written to the output peripherals. The input/processing/output stages were run in parallel, increasing machine utilisation. On larger machines it was possible to run multiple jobs simultaneously.
George 1 and 2 ran as simple programs under executive (with trusted status that allowed them to control user programs). George 3 was a complete operating system in itself, it used a much reduced executive responsible only for handling low level hardware access. George 3 implemented both batch processing and Multiple online programming (MOP) – interactive use from terminals.
George 4 was introduced with the availability of paging
Paging
In computer operating systems, paging is one of the memory-management schemes by which a computer can store and retrieve data from secondary storage for use in main memory. In the paging memory-management scheme, the operating system retrieves data from secondary storage in same-size blocks called...
hardware on the later machines and implemented paged virtual memory
Virtual memory
In computing, virtual memory is a memory management technique developed for multitasking kernels. This technique virtualizes a computer architecture's various forms of computer data storage , allowing a program to be designed as though there is only one kind of memory, "virtual" memory, which...
instead of the simple swapping used by George 3.
Programming Languages
ICT initially provided the PLAN assembly languageAssembler
Assembler may refer to:* Assembler , for an assembly language, a computer program to translate between lower-level representations of computer programs...
and later the big three, ALGOL 60
ALGOL 60
ALGOL 60 is a member of the ALGOL family of computer programming languages. It gave rise to many other programming languages, including BCPL, B, Pascal, Simula, C, and many others. ALGOL 58 introduced code blocks and the begin and end pairs for delimiting them...
, COBOL
COBOL
COBOL is one of the oldest programming languages. Its name is an acronym for COmmon Business-Oriented Language, defining its primary domain in business, finance, and administrative systems for companies and governments....
and FORTRAN 66.
The compilers were released in various versions, of increasing sophistication. Initially paper tape and cards were used for input and output, later magnetic tape and finally disk files.
The first versions of the compilers ran in very limited space, starting around 4K words for PLAN and NICOL and as little as 16K words for FORTRAN and ALGOL. Later versions for the George 3 and 4 operating systems expanded to sizes as large as 48K words.
Other languages available included:
- PLASYD – an alternative assembly language modeled on PL/360, much used by the Atlas Computer LaboratoryAtlas Computer LaboratoryThe Atlas Computer Laboratory on the Chilton, Oxfordshire campus shared by the Harwell Laboratory was one of the major computer laboratories in the world, which operated between 1961 and 1975 to provide a service to British scientists at a time when powerful computers were not usually available...
. - NICOL – The NIneteen Hundred COmmercial Language. A simple report generation language in the RPG vein, much used on the small 1901 replacing cardPunched cardA 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...
tabulatorTabulating machineThe tabulating machine was an electrical device designed to assist in summarizing information and, later, accounting. Invented by Herman Hollerith, the machine was developed to help process data for the 1890 U.S. Census...
systems. - JEANJEANJEAN was a dialect of the JOSS programming language developed for and used on ICT 1900 series computers in the late 1960s and early 1970s; it was implemented under the MINIMOP operating system. It was used at the University of Southampton....
– a dialect of JOSSJOSSJOSS was one of the very first interactive, time sharing programming languages.JOSS I, developed by J. Clifford Shaw at RAND was first implemented, in beta form, on the JOHNNIAC computer in May 1963...
, a conversational language similar in capabilities to BASICBASICBASIC is a family of general-purpose, high-level programming languages whose design philosophy emphasizes ease of use - the name is an acronym from Beginner's All-purpose Symbolic Instruction Code.... - SOBSSouthampton BASIC SystemSouthampton BASIC System was a dialect of the BASIC programming language developed for and used on ICT 1900 series computers in the late 60s and early 70s; it was implemented under the MINIMOP operating system at the University of Southampton....
– the SouthamptonUniversity of SouthamptonThe University of Southampton is a British public university located in the city of Southampton, England, a member of the Russell Group. The origins of the university can be dated back to the founding of the Hartley Institution in 1862 by Henry Robertson Hartley. In 1902, the Institution developed...
BASICBASICBASIC is a family of general-purpose, high-level programming languages whose design philosophy emphasizes ease of use - the name is an acronym from Beginner's All-purpose Symbolic Instruction Code....
System. - POP-2POP-2POP-2, often referred to as POP2 was a programming language developed around 1970 from the earlier language POP-1 by Robin Popplestone and Rod Burstall at the University of Edinburgh. It drew roots from many sources: the languages LISP and ALGOL 60, and theoretical ideas from Landin...
– From the University of EdinburghUniversity of EdinburghThe University of Edinburgh, founded in 1583, is a public research university located in Edinburgh, the capital of Scotland, and a UNESCO World Heritage Site. The university is deeply embedded in the fabric of the city, with many of the buildings in the historic Old Town belonging to the university...
. A stack based list-processing language. - ALGOL 68RALGOL 68RALGOL 68-R was the first implementation of the Algorithmic language ALGOL 68.In December 1968 the report on the Algorithmic language ALGOL 68 was published. On 20–24 July 1970 a working conference was arranged by the IFIP to discuss the problems of implementation of the language, a small team from...
– The Royal Radar EstablishmentRoyal Radar EstablishmentThe name Royal Radar Establishment was given to the existing Radar Research Establishment following a visit by Queen Elizabeth II in 1957. Both names were abbreviated to RRE. The establishment had been formed, under its first name, in 1953 by merging the Telecommunications Research Establishment ...
wrote one of the first Algol 68ALGOL 68ALGOL 68 isan imperative computerprogramming language that was conceived as a successor to theALGOL 60 programming language, designed with the goal of a...
compilers for the 1900. - PascalPascal (programming language)Pascal is an influential imperative and procedural programming language, designed in 1968/9 and published in 1970 by Niklaus Wirth as a small and efficient language intended to encourage good programming practices using structured programming and data structuring.A derivative known as Object Pascal...
– The Queen's University Belfast ported the CDC Pascal compiler to the 1900. - FORTRAN 77 – The University of SalfordUniversity of SalfordThe University of Salford is a campus university based in Salford, Greater Manchester, England with approximately 20,000 registered students. The main campus is about west of Manchester city centre, on the A6, opposite the former home of the physicist, James Prescott Joule and the Working Class...
produced a FORTRAN 77 compiler for George 3. It was unusual in that it used 8 bit characters and the ASCIIASCIIThe American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...
character set internally. Silverfrost FTN95Silverfrost FTN95Silverfrost FTN95: Fortran for Windows is a Fortran compiler for Microsoft Windows. It generates code for native IA-32 Win32 executables and for Microsoft's .NET platform. FTN95 comes in three licensed editions: Commercial, Academic and Personal. The Personal edition is free and is designed for...
, a Fortran 95 compiler for Windows is a distant descendant. - BCPLBCPLBCPL is a procedural, imperative, and structured computer programming language designed by Martin Richards of the University of Cambridge in 1966.- Design :...
– Bernard Sufrin ported Martin Richards's IBM 360 compiler to the 1900 architecture in mid-1969 at Essex University. BCPLBCPLBCPL is a procedural, imperative, and structured computer programming language designed by Martin Richards of the University of Cambridge in 1966.- Design :...
is antecedent of CC (programming language)C is a general-purpose computer programming language developed between 1969 and 1973 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system....
.
Applications Software
Like many contemporary machines much application software was bundled with the basic system, including the compilers and utility programs. Other software was available as paid options from ICT or other sources, including such exotic packages as Storm Sewer Design and Analysis.-
SCAN– Stock control system (Acronym: Stock Control and Analysis on Nineteen-hundred) -
PERT– Project management system (Acronym: Project Evaluation and Review Technique) -
PROSPER– Financial planning system (forerunner of today's spreadsheet programs) -
NIMMS– Production control system (Acronym: Nineteen-hundred Integrated Modular Management System) -
COMPAY– Company payroll program -
FIND– File Interrogation of Nineteenhundred Data (data analysis package) -
Filetab– A tool for generating reports based on decision tables.FiletabFiletab is a decision table-based computer programming language.Filetab has a long history, originally designed in the late 1960s and descended from the DETAB programming...