Manchester Mark 1 was one of the world's first stored program computers.

The Manchester Mark I was one of the earliest electronic computers and the first electronic stored program computer, built at the University of Manchester in England, in 1949. It was also called Manchester Automatic Digital Machine, or MADM. It was developed from the Small-Scale Experimental Machine (SSEM) or "Baby". It is especially historically significant due to its pioneering inclusion of a kind of index register in its architecture, as well as being the platform on which Autocode was developed, one of the first "high-level" computer languages. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Look up Electronic in Wiktionary, the free dictionary. ... This article is about the machine. ... Look up Electronic in Wiktionary, the free dictionary. ... The so-called von Neumann architecture is a model for a computing machine that uses a single storage structure to hold both the set of instructions on how to perform the computation and the data required or generated by the computation. ... This article is about the machine. ... Affiliations: Russell Group, EUA, N8 Group, NWUA, Worldwide Universities Network (WUN), Association of Commonwealth Universities Website: http://www. ... For other uses, see England (disambiguation). ... Year 1949 (MCMXLIX) was a common year starting on Saturday (link will display the full calendar) of the Gregorian calendar. ... Replica of the SSEM The Manchester Small-Scale Experimental Machine (SSEM), nicknamed Baby, was the first stored-program computer to run a program, on June 21, 1948. ... An index register in a computer CPU is a processor register used for modifying operand addresses during the run of a program, typically for doing vector/array operations. ... Autocode is a class of simple high-level programming languages devised for a series of machines at the Universities of Manchester and Cambridge. ... Look up computer language & a Brief History of it in Wiktionary, the free dictionary. ...

Development of the Mark I started after the SSEM demonstrated the utility of the stored-program approach, which dramatically improved a machine's flexibility. This approach was being looked at by other researchers, notably Alan Turing's efforts on the Pilot ACE, Cambridge University's EDSAC, and EDVAC in the US. The SSEM differed primarily in the choice of memory system, using the much faster Williams tubes instead of mercury delay lines. Alan Mathison Turing, OBE, FRS (pronounced ) (23 June 1912 – 7 June 1954) was an English mathematician, logician and cryptographer. ... The Pilot ACE was one of the first computers built in the United Kingdom, at the National Physical Laboratory (NPL) in the late 1940s. ... The University of Cambridge (often Cambridge University), located in Cambridge, England, is the second-oldest university in the English-speaking world and has a reputation as one of the most prestigious universities in the world. ... EDSAC EDSAC (Electronic Delay Storage Automatic Calculator) was an early British computer (one of the first computers to be created). ... The EDVAC as installed in Building 328 at the Ballistics Research Laboratory. ... The Williams tube or (more accurately) the Williams-Kilburn tube (after Freddie Williams and coworker Tom Kilburn), developed about 1946 or 1947, was a cathode ray tube used to store electronic data. ... Mercury memory of UNIVAC I (1951) Delay line memory was a form of computer memory used on some of the earliest digital computers, such as the EDSAC and UNIVAC I. // The basic concept of the delay line originated with World War II radar research, as a system to reduce clutter...

With the successful demonstration of the SSEM, the British government contracted Ferranti in October 1948 to deliver a full-scale machine based on its basic concepts. Key improvements in the design were going to include a magnetic drum for loading programs into the machine's Williams tube memory, replacing the SSEM's paper tape, the addition of index registers and a hardware multiplier. The word size was increased slightly from 32-bits to 40, read and written as four 10-bit "short words". Instructions used a single short word, addresses two, and numeric data four. Although the 10-bit instructions could hold up to 1,024 different codes, the machine only had 30 in its final version. Standard instruction time was 1,800 microseconds, but multiplication was much slower. The Ferranti Mark 1 (based on the Manchester Mark 1) had an addition time of 1,200 microseconds and a multiplication time of 2,160 microseconds. Ferranti or Ferranti International plc by the time of its collapse, was a major UK electrical engineering and equipment firm, known primarily for defence electronics and power grid systems. ... The Magnetic Drum was invented by G. Taushek in 1932 in Austria. ... A roll of punched tape Punched tape is an old-fashioned form of data storage, consisting of a long strip of paper in which holes are punched to store data. ... To help compare orders of magnitude of different times this page lists times between 10−6 seconds and 10−5 seconds (1. ... Ferranti or Ferranti International plc by the time of its collapse, was a major UK electrical engineering and equipment firm, known primarily for defence electronics and power grid systems. ...

The SSEM included two registers on its Williams tube, the accumulator A and program counter C. Mark I added another, D, for holding one side of a multiplication, leaving B the natural place to hold the index register. Since the system used a 20-bit address, the B-line on the tube held two address offsets. This is the earliest known implementation of such index/base registers – an important innovation in computer architecture, unknown in other machines until the emergence of second-generation computers (approximately 1955–1964). The Mark I included two tubes, each storing 64 rows ("double density") of 40 points, for a total of 128 words. 64 words was considered to be a single "page", so the system stored 4 pages. Freddie Williams deliberately sized the drum to store two "pages" of Williams tube data – that is, 2x32x40 = 2,560 bits – per track, and 32 tracks in total. The drum was timed to spin at the refresh rate of the Willams tubes, allowing pages to be read and written between refreshes, a task that took about 30 cycles. This article is about a computer processor register. ... The program counter (also called the instruction pointer in some computers) is a register in a computer processor which indicates where the computer is in its instruction sequence. ... An index register in a computer CPU is a processor register used for modifying operand addresses during the run of a program, typically for doing vector/array operations. ... Computing hardware has been an important component of the process of calculation and data storage since it became useful for numerical values to be processed and shared. ... Sir Frederic Calland Williams (1911 - 1977), known as Freddie Williams, was an English engineer. ...

The first version of the machine was running in April 1949, known as the Intermediary Version. This version was largely feature complete, but lacked input/output instructions to move data from the drum to the tubes or paper tape to the drum. Energy Input: The energy placed into a reaction. ...

The first realistic program to be run on the Mark I was a test of Mersenne primes, run in early April 1949. The computer ran error-free for 9 hours on the night of June 16-17, 1949. The Final Specification version was completed in October 1949, adding a second drum and various instructions to read one line of data to and from the drum to tubes and drum to paper tape. Over time the existing drums were used to store more data, typically 47 tracks. In mathematics, a Mersenne prime is a prime number that is one less than a power of two. ...

The machine used 4,200 vacuum tubes for logic, which proved to be a terrible reliability problem. In one calculation the machine spent almost 25% of its time "down", due both to the tubes and the drums. Nevertheless the University was successful in attracting commercial users to rent time on the machine for £50 an hour. Structure of a vacuum tube diode Structure of a vacuum tube triode In electronics, a vacuum tube, electron tube, or (outside North America) thermionic valve or just valve, is a device used to amplify, switch or modify a signal by controlling the movement of electrons in an evacuated space. ... Downtime refers to a period of time or a percentage of a timespan that a machine or system (usually a computer server) is offline or not functioning, usually as a result of either system failure (such as a crash) or routine maintenance. ...

After the Mark I was running, development continued in several directions. Dick Grimsdale and Doug Webb attempted to improve the reliability of the Mark I by building the machine out of transistors, perhaps being the first transistorized computer when their prototype ran in November 1953. Their work was later picked up by Metropolitan-Vickers to create the Metrovick 950, of which seven were sold. Assorted discrete transistors A transistor is a semiconductor device, commonly used as an amplifier or an electrically controlled switch. ... Metropolitan-Vickers, or Metrovick, was a British heavy industrial firm of the early-to-mid 20th century formerly known as British Westinghouse. ... The Metrovick 950 was the first commercial transistorized computer, built from 1955 onwards by British company Metropolitan-Vickers to the extent of seven machines. ...

The main Mark I team, Tom Kilburn and Freddie Williams, concluded that computers would be used more in scientific roles than pure math, and decided to start development of a new model including a floating point unit. The resulting machine, Meg, was both simpler than the Mark I as well as much faster for math problems. Ferranti, who had built the Mark I, rebuilt Meg with core memory and sold the resulting design as the Ferranti Mercury. Tom Kilburn (August 11, 1921 - January 17, 2001) was an English engineer. ... Sir Frederic Calland Williams (June 26, 1911. ... A floating point unit (FPU) is a part of a computer system specially designed to carry out operations on floating point numbers. ... Ferranti or Ferranti International plc by the time of its collapse, was a major UK electrical engineering and equipment firm, known primarily for defence electronics and power grid systems. ... A 16×16 cm area core memory plane of 128×128 bits, i. ... The Mercury was an early 1950s commercial computer built by Ferranti. ...

Among the Mark I team were mathematicians Conway Berners-Lee and Mary Lee Woods, who would later marry; their son, Tim Berners-Lee, is acknowledged as the inventor of the World Wide Web. Conway Berners-Lee was a British mathematician who worked in the team that developed the Manchester Mark I computer at the University of Manchester, England. ... Mary Lee Woods was a British mathematician who worked in the team that developed the Manchester Mark I computer at the University of Manchester, England. ... Sir Tim Berners-Lee Sir Tim (Timothy John) Berners-Lee, KBE (TimBL or TBL) (b. ... The World Wide Web and WWW redirect here. ...

The Met.Office used the Mark I to develop its first prototype computer programs for weather forecasting; they used difference equations to calculate atmospheric pressure.

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Bush (R)  - Vice President Dick Cheney (R) Independence - Declared - Recognized... For other uses, see Decimal (disambiguation). ... Surface mount electronic components Electronics is the study of the flow of charge through various materials and devices such as semiconductors, resistors, inductors, capacitors, nano-structures and vacuum tubes. ... Replica of the SSEM The Manchester Small-Scale Experimental Machine (SSEM), nicknamed Baby, was the first stored-program computer to run a program, on June 21, 1948. ... The United Kingdom of Great Britain and Northern Ireland is a country in western Europe, and member of the Commonwealth of Nations, the G8, the European Union, and NATO. Usually known simply as the United Kingdom, the UK, or (inaccurately) as Great Britain or Britain, the UK has four constituent... The binary numeral system, or base-2 number system, is a numeral system that represents numeric values using two symbols, usually 0 and 1. ... 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Mercury memory of UNIVAC I (1951) Delay line memory was a form of computer memory used on some of the earliest digital computers, such as the EDSAC and UNIVAC I. // The basic concept of the delay line originated with World War II radar research, as a system to reduce clutter... The United Kingdom of Great Britain and Northern Ireland is a country in western Europe, and member of the Commonwealth of Nations, the G8, the European Union, and NATO. Usually known simply as the United Kingdom, the UK, or (inaccurately) as Great Britain or Britain, the UK has four constituent... The binary numeral system, or base-2 number system, is a numeral system that represents numeric values using two symbols, usually 0 and 1. ... Surface mount electronic components Electronics is the study of the flow of charge through various materials and devices such as semiconductors, resistors, inductors, capacitors, nano-structures and vacuum tubes. ... 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Surface mount electronic components Electronics is the study of the flow of charge through various materials and devices such as semiconductors, resistors, inductors, capacitors, nano-structures and vacuum tubes. ... The so-called von Neumann architecture is a model for a computing machine that uses a single storage structure to hold both the set of instructions on how to perform the computation and the data required or generated by the computation. ... Mercury memory of UNIVAC I (1951) Delay line memory was a form of computer memory used on some of the earliest digital computers, such as the EDSAC and UNIVAC I. // The basic concept of the delay line originated with World War II radar research, as a system to reduce clutter...

References

• Lavington, Simon H. (1980). Early British Computers. Manchester University Press. ISBN 0-932376-08-8. 

External links

• The Manchester Mark I
• Early computers at Manchester University
• A simulator of the Manchester Mark I, executing Christopher Strachey's Love letter algorithm from 1952
• Lavington, Simon H. (Jul-Sept 1993). "Manchester Computer Architectures, 1948-1975". IEEE Annals of the History of Computing 15 (3): 44–54. IEEE. doi:http://doi.ieeecomputersociety.org/10.1109/85.222841.