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{{History of computing}}
The '''history of computing hardware'''
The first aids to computation were purely mechanical devices which required the operator to set up the initial values of an elementary [[arithmetic]] operation, then manipulate the device to obtain the result. In later stages, computing devices began representing numbers in continuous forms, such as by distance along a scale, rotation of a shaft, or a specific voltage level. Numbers could also be represented in the form of digits, automatically manipulated by a mechanism. Although this approach generally required more complex mechanisms, it greatly increased the precision of results. The development of transistor technology, followed by the invention of integrated circuit chips, led to revolutionary breakthroughs.
▲The '''history of computing hardware''' covers the developments from early simple devices to aid [[calculation]] to modern day [[computer]]s.
==Early devices==
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Devices have been used to aid computation for thousands of years, mostly using [[one-to-one correspondence]] with [[finger-counting|fingers]]. The earliest counting device was probably a form of [[tally stick]]. The [[Lebombo bone]] from the mountains between [[Eswatini]] and [[South Africa]] may be the oldest known mathematical artifact.<ref name="Selin2008">{{cite book |first=Helaine|last=Selin|title=Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures |url=https://books.google.com/books?id=kt9DIY1g9HYC&pg=PA1356|date=12 March 2008 |publisher=Springer Science & Business Media |isbn=978-1-4020-4559-2|page=1356|bibcode=2008ehst.book.....S|access-date=2020-05-27}}</ref> It dates from 35,000 BCE and consists of 29 distinct notches that were deliberately cut into a [[baboon]]'s [[fibula]].<ref>{{mathworld |title=Lebombo Bone |urlname=LebomboBone |author=Pegg, Ed Jr. |author-link=Ed Pegg Jr. |ref=none}}</ref><ref>{{cite book| last=Darling| first=David| title=The Universal Book of Mathematics From Abracadabra to Zeno's Paradoxes| year=2004| publisher=John Wiley & Sons| isbn= 978-0-471-27047-8}}</ref> Later record keeping aids throughout the [[Fertile Crescent]] included calculi (clay spheres, cones, etc.) which represented counts of items, probably livestock or grains, sealed in hollow unbaked clay containers.{{efn|According to {{harvnb|Schmandt-Besserat|1981}}, these clay containers contained tokens, the total of which were the count of objects being transferred. The containers thus served as something of a [[bill of lading]] or an accounts book. In order to avoid breaking open the containers, first, clay impressions of the tokens were placed on the outside of the containers, for the count; the shapes of the impressions were abstracted into stylized marks; finally, the abstract marks were systematically used as numerals; these numerals were finally formalized as numbers. Eventually (Schmandt-Besserat estimates it took 5000 years.<ref>{{cite web |last=Schmandt-Besserat |first=Denise |title=The Evolution of Writing |url=https://sites.utexas.edu/dsb/files/2014/01/evolution_writing.pdf |archive-url=https://web.archive.org/web/20120130084757/http://www.laits.utexas.edu/ghazal/Chap1/dsb/chapter1.html |archive-date=2012-01-30 |url-status=live}}</ref>) the marks on the outside of the containers were all that were needed to convey the count, and the clay containers evolved into clay tablets with marks for the count.}}<ref>{{cite book |first=Eleanor |last=Robson |author-link=Eleanor Robson |year=2008 |title=Mathematics in Ancient Iraq |publisher=Princeton University Press |isbn=978-0-691-09182-2 |quote-page=5 |quote=calculi were in use in Iraq for primitive accounting systems as early as 3200–3000 BCE, with commodity-specific counting representation systems. Balanced accounting was in use by 3000–2350 BCE, and a [[sexagesimal number system]] was in use 2350–2000 BCE.}}</ref>{{efn|Robson has recommended at least one supplement to {{harvp|Schmandt-Besserat|1981}}, e.g., a review, {{cite journal |doi=10.1126/science.260.5114.1670 |last=Englund |first=R. |date=1993 |title=The origins of script |journal=Science |volume=260 |issue=5114 |pages=1670–1671 |pmid=17810210}}<ref>{{cite web |first=Eleanor |last=Robson |title=Bibliography of Mesopotamian Mathematics |url=https://it.stlawu.edu/~dmelvill/mesomath/erbiblio.html#genhist |access-date=2016-07-06 |archive-url=https://web.archive.org/web/20160616161807/http://it.stlawu.edu/~dmelvill/mesomath/erbiblio.html#genhist |url-status=dead |archive-date=2016-06-16}}</ref>}} The use of [[counting rods]] is one example. The [[abacus]] was early used for arithmetic tasks. What we now call the [[Roman abacus]] was used in [[Babylonia]] as early as {{circa|2700}}–2300 BC. Since then, many other forms of reckoning boards or tables have been invented. In a medieval European [[counting house]], a checkered cloth would be placed on a table, and markers moved around on it according to certain rules, as an aid to calculating sums of money.
Several [[analog computer]]s were constructed in ancient and medieval times to perform astronomical calculations. These included the [[astrolabe]] and [[Antikythera mechanism]] from the [[Hellenistic world]] (c. 150–100 BC).{{sfn|Lazos|1994}} In [[Roman Egypt]], [[Hero of Alexandria]] (c. 10–70 AD) made mechanical devices including [[Automaton|automata]] and a programmable [[cart]].<ref>{{citation |title=A programmable robot from 60 AD |first=Noel |last=Sharkey |date=4 July 2007 |volume=2611 |publisher=New Scientist |url=https://www.newscientist.com/blog/technology/2007/07/programmable-robot-from-60ad.html|archive-url=https://web.archive.org/web/20171213205451/https://www.newscientist.com/blog/technology/2007/07/programmable-robot-from-60ad.html|archive-date=13 December 2017}}</ref> The steam-powered automatic flute described by the ''[[Book of Ingenious Devices]]'' (850) by the Persian-Baghdadi [[Banū Mūsā brothers]] may have been the first programmable device.<ref name=Koetsier>{{Citation |last1=Koetsier |first1=Teun |year=2001 |title=On the prehistory of programmable machines: musical automata, looms, calculators |journal=Mechanism and Machine Theory |volume=36 |issue=5 |pages=589–603 |publisher=Elsevier |doi=10.1016/S0094-114X(01)00005-2 |postscript=.}}</ref>
Other early mechanical devices used to perform one or another type of calculations include the [[planisphere]] and other mechanical computing devices invented by [[Al-Biruni]] (c. AD 1000); the [[equatorium]] and universal latitude-independent astrolabe by [[Al-Zarqali]] (c. AD 1015); the astronomical analog computers of other medieval [[Islamic astronomy|Muslim astronomers]] and engineers; and the astronomical [[clock tower]] of [[Su Song]] (1094) during the [[Song dynasty]]. The [[castle clock]], a [[hydropower]]ed mechanical [[astronomical clock]] invented by [[Ismail al-Jazari]] in 1206, was the first [[Computer programming|programmable]] analog computer.{{Disputed inline|for=The cited source doesn't support the claim, and the claim is misleading.|date=June 2022}}<ref name="Ancient Discoveries">{{citation|title=Episode 11: Ancient Robots|work=[[Ancient Discoveries]]|publisher=[[History Channel]]|url=https://www.youtube.com/watch?v=rxjbaQl0ad8|url-status=dead |access-date=2008-09-06|archive-date=2014-03-01 |archive-url=https://web.archive.org/web/20140301151115/https://www.youtube.com/watch?v=rxjbaQl0ad8}}</ref><ref>{{Cite book |last=Turner |first=Howard R. |title=Science in Medieval Islam: An Illustrated Introduction |page=184 |date=1997 |publisher=University of Texas press |isbn=978-0-292-78149-8 |___location=Austin}}</ref><ref>{{cite magazine |author-link=Donald Routledge Hill |last=Hill |first=Donald Routledge |title=Mechanical Engineering in the Medieval Near East |magazine=Scientific American |date=May 1991 |pages=64–69}} ([[cf.]] {{cite web |last=Hill |first=Donald Routledge |title=IX. Mechanical Engineering |url= http://home.swipnet.se/islam/articles/HistoryofSciences.htm |work=History of Sciences in the Islamic World |archive-url=https://web.archive.org/web/20071225091836/http://home.swipnet.se/islam/articles/HistoryofSciences.htm |archive-date=2007-12-25 |url-status=dead}})</ref> [[Ramon Llull]] invented the Lullian Circle: a notional machine for calculating answers to philosophical questions (in this case, to do with Christianity) via logical combinatorics. This idea was taken up by [[Gottfried Leibniz|Leibniz]] centuries later, and is thus one of the founding elements in computing and [[information science]].
=== Renaissance calculating tools===
Scottish mathematician and physicist [[John Napier]] discovered that the multiplication and division of numbers could be performed by the addition and subtraction, respectively, of the [[logarithm]]s of those numbers. While producing the first logarithmic tables, Napier needed to perform many tedious multiplications. It was at this point that he designed his '[[Napier's bones]]', an abacus-like device that greatly simplified calculations that involved multiplication and division.{{efn|A Spanish implementation of [[Napier's bones]] (1617), is documented in {{harvnb|Montaner|Simon|1887|pp=19–20}}.}}
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===Mechanical calculators===
In 1609, [[Guidobaldo del Monte]] made a mechanical multiplier to calculate fractions of a degree. Based on a system of four gears, the rotation of an index on one quadrant corresponds to 60 rotations of another index on an opposite quadrant.<ref>{{cite journal |first=Domenico Bertolini|last=Meli|date=1992|doi=10.1163/182539192x00019 |title=Guidobaldo Dal Monte and the Archimedean Revival |journal=Nuncius|number=1|pages=3–34|volume=7}}</ref> Thanks to this machine, errors in the calculation of first, second, third and quarter degrees can be avoided. Guidobaldo is the first to document the use of gears for mechanical calculation.
[[Wilhelm Schickard]], a German [[polymath]], designed a calculating machine in 1623 which combined a mechanized form of Napier's rods with the world's first mechanical adding machine built into the base. Because it made use of a single-tooth gear there were circumstances in which its carry mechanism would jam.<ref>{{harvnb|Williams|1997|p=128}} "...the single-tooth gear, like that used by Schickard, would not do for a general carry mechanism. The single-tooth gear works fine if the carry is only going to be propagated a few places but, if the carry has to be propagated several places along the accumulator, the force needed to operate the machine would be of such magnitude that it would do damage to the delicate gear works."</ref> A fire destroyed at least one of the machines in 1624 and it is believed Schickard was too disheartened to build another.
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[[File:Early SSA accounting operations.jpg|thumb|upright|left|[[IBM]] punched-card accounting machines, 1936]]
In the late 1880s, the American [[Herman Hollerith]] invented data storage on [[punched card]]s that could then be read by a machine.<ref>{{cite web |url=https://www.columbia.edu/acis/history/hollerith.html |title=Herman Hollerith |website=Columbia University Computing History |publisher=Columbia University ACIS |access-date=2010-01-30 |archive-date=2011-05-13 |archive-url=https://web.archive.org/web/20110513134315/http://www.columbia.edu/acis/history/hollerith.html |url-status=live}}</ref> To process these punched cards, he invented the [[tabulating machine|tabulator]] and the [[keypunch]] machine. His machines used electromechanical [[relay]]s and [[Mechanical counter|counters]].<ref>{{cite book|author1-link=Leon E. Truesdell |last=Truesdell |first=Leon E. |title=The Development of Punch Card Tabulation in the Bureau of the Census 1890–1940|pages=47–55 |year=1965 |publisher=US GPO}}</ref> Hollerith's method was used in the [[1890 United States
By 1920, electromechanical tabulating machines could add, subtract, and print accumulated totals.<ref>{{cite web |url=https://www.ibm.com/ibm/history/history/year_1920.html |website=IBM Archives |title=1920 |date=23 January 2003 |access-date=2020-12-01 |archive-date=2020-10-29 |archive-url=https://web.archive.org/web/20201029080349/https://www.ibm.com/ibm/history/history/year_1920.html |url-status=live }}</ref> Machine functions were directed <!-- other than the calculators (602, 604...) unit record machines are not programmed – there is no sequence of operations on their control panels. See [[plugboard]]--> by inserting dozens of wire jumpers into removable [[plugboard|control panel]]s. When the United States instituted [[Social Security (United States)|Social Security]] in 1935, IBM punched-card systems were used to process records of 26 million workers.<ref>{{cite web |url= https://www.ibm.com/ibm/history/history/decade_1930.html |website=IBM Archives |title=Chronological History of IBM: 1930s |date=23 January 2003 |access-date=2020-12-01 |archive-date=2020-12-03 |archive-url=https://web.archive.org/web/20201203145246/https://www.ibm.com/ibm/history/history/decade_1930.html |url-status=live }}</ref> Punched cards became ubiquitous in industry and government for accounting and administration.
[[Leslie Comrie]]'s articles on punched-card methods<ref>Leslie Comrie [https://adsabs.harvard.edu/full/1928MNRAS..88..506C (1928) On the Construction of Tables by Interpolation]</ref> and [[W. J. Eckert]]'s publication of ''Punched Card Methods in Scientific Computation'' in 1940, described punched-card techniques sufficiently advanced to solve some differential equations or perform multiplication and division using floating-point representations, all on punched cards and [[unit record equipment|unit record machines]].{{sfn|Eckert|1935}} Such machines were used during World War II for cryptographic statistical processing,<ref>{{citation | editor-last = Erskine | editor-first = Ralph | editor2-last = Smith | editor2-first = Michael | editor2-link = Michael Smith (newspaper reporter) | title = The Bletchley Park Codebreakers | publisher = Biteback Publishing Ltd | year = 2011 | page = 134| isbn = 978-184954078-0}} Updated and extended version of ''Action This Day: From Breaking of the Enigma Code to the Birth of the Modern Computer'' Bantam Press 2001</ref> as well as a vast number of administrative uses.
===Calculators===
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==First proposed general-purpose computing device==
{{Main|Analytical Engine}}
[[File:Difference engine plate 1853.jpg|thumb|A portion of [[Charles Babbage|Babbage]]'s [[Difference Engine]] ]][[File:AnalyticalMachine Babbage London.jpg|thumb|left|Trial model of a part of the Analytical Engine, built by Babbage, as displayed at the Science Museum, London]]
The [[Industrial Revolution]] (late 18th to early 19th century) had a significant impact on the evolution of computing hardware, as the era's rapid advancements in machinery and manufacturing laid the groundwork for mechanized and automated computing. Industrial needs for precise, large-scale calculations—especially in fields such as navigation, engineering, and finance—prompted innovations in both design and function, setting the stage for devices like [[Charles Babbage|Charles Babbage's]] [[difference engine]] (1822).<ref>{{Cite book |last=Babbage |first=Charles |url=http://dx.doi.org/10.1017/cbo9781139103671 |title=Passages from the Life of a Philosopher |date=2011-10-12 |publisher=Cambridge University Press |doi=10.1017/cbo9781139103671 |isbn=978-1-108-03788-4}}</ref><ref>{{Cite book |last=Babbage |first=Charles |url=http://dx.doi.org/10.1017/cbo9780511696374 |title=On the Economy of Machinery and Manufactures |date=2010-03-04 |publisher=Cambridge University Press |doi=10.1017/cbo9780511696374 |isbn=978-1-108-00910-2}}</ref> This mechanical device was intended to automate the calculation of polynomial functions and represented one of the earliest applications of computational logic.<ref>{{Cite journal |last=Hutton |first=D.M. |date=2002-08-01 |title=The Difference Engine: Charles Babbage and the Quest to Build the First Computer |url=http://dx.doi.org/10.1108/k.2002.06731fae.009 |journal=Kybernetes |volume=31 |issue=6 |doi=10.1108/k.2002.06731fae.009 |issn=0368-492X|url-access=subscription }}</ref>
Babbage, often regarded as the "father of the computer," envisioned a fully mechanical system of gears and wheels, powered by steam, capable of handling complex calculations that previously required intensive manual labor.<ref>{{Cite journal |last=Tropp |first=Henry S. |date=December 1975 |title=''The Origins of Digital Computers: Selected Papers''. Brian Randell |url=http://dx.doi.org/10.1086/351520 |journal=Isis |volume=66 |issue=4 |pages=572–573 |doi=10.1086/351520 |issn=0021-1753|url-access=subscription }}</ref> His difference engine, designed to aid navigational calculations, ultimately led him to conceive the [[analytical engine]] in 1833.<ref>{{Cite journal |last1=W. |first1=J. W. |last2=Hyman |first2=Anthony |date=April 1986 |title=Charles Babbage, Pioneer of the Computer. |url=http://dx.doi.org/10.2307/2008013 |journal=Mathematics of Computation |volume=46 |issue=174 |pages=759 |doi=10.2307/2008013 |jstor=2008013 |issn=0025-5718|url-access=subscription }}</ref> This concept, far more advanced than his difference engine, included an [[arithmetic logic unit]], control flow through conditional branching and loops, and integrated memory.<ref>{{Cite book |last1=Campbell-Kelly |first1=Martin |last2=Aspray |first2=William |last3=Ensmenger |first3=Nathan |last4=Yost |first4=Jeffrey R. |date=2018-04-20 |title=Computer |url=http://dx.doi.org/10.4324/9780429495373 |doi=10.4324/9780429495373|isbn=978-0-429-49537-3 }}</ref> Babbage's plans made his analytical engine the first general-purpose design that could be described as [[Turing completeness|Turing-complete]] in modern terms.<ref>{{Citation |last=Turing |first=Alan |title=Computing Machinery and Intelligence (1950) |date=2004-09-09 |work=The Essential Turing |pages=433–464 |url=http://dx.doi.org/10.1093/oso/9780198250791.003.0017 |access-date=2024-10-30 |publisher=Oxford University PressOxford |doi=10.1093/oso/9780198250791.003.0017 |isbn=978-0-19-825079-1|url-access=subscription }}</ref><ref>{{Cite book |last=Davis |first=Martin |date=2018-02-28 |title=the Universal Computer |url=http://dx.doi.org/10.1201/9781315144726 |doi=10.1201/9781315144726|isbn=978-1-315-14472-6 }}</ref>
The analytical engine was programmed using [[Punched card input/output|punched cards]], a method adapted from the [[Jacquard machine|Jacquard loom]] invented by [[Joseph Marie Jacquard]] in 1804, which controlled textile patterns with a sequence of punched cards.<ref>{{Cite journal |last1=d'Ucel |first1=Jeanne |last2=Dib |first2=Mohammed |date=1958 |title=Le métier à tisser |url=http://dx.doi.org/10.2307/40098349 |journal=Books Abroad |volume=32 |issue=3 |pages=278 |doi=10.2307/40098349 |jstor=40098349 |issn=0006-7431|url-access=subscription }}</ref> These cards became foundational in later computing systems as well.<ref>{{Cite book |last=Heide |first=Lars |url=http://dx.doi.org/10.1353/book.3454 |title=Punched-Card Systems and the Early Information Explosion, 1880–1945 |date=2009 |publisher=Johns Hopkins University Press |doi=10.1353/book.3454 |isbn=978-0-8018-9143-4}}</ref> Babbage's machine would have featured multiple output devices, including a printer, a curve plotter, and even a bell, demonstrating his ambition for versatile computational applications beyond simple arithmetic.<ref>{{Cite journal |last=Bromley |first=A.G. |date=1998 |title=Charles Babbage's Analytical Engine, 1838 |url=http://dx.doi.org/10.1109/85.728228 |journal=IEEE Annals of the History of Computing |volume=20 |issue=4 |pages=29–45 |doi=10.1109/85.728228 |issn=1058-6180|url-access=subscription }}</ref>
[[Ada Lovelace]] expanded on Babbage's vision by conceptualizing algorithms that could be executed by his machine.<ref>{{Cite journal |last=Toole |first=Betty Alexandra |date=March 1991 |title=Ada, an analyst and a metaphysician |url=http://dx.doi.org/10.1145/122028.122031 |journal=ACM SIGAda Ada Letters |volume=XI |issue=2 |pages=60–71 |doi=10.1145/122028.122031 |issn=1094-3641|url-access=subscription }}</ref> Her notes on the analytical engine, written in the 1840s, are now recognized as the earliest examples of computer programming.<ref>{{Cite book |last1=Howard |first1=Emily |last2=De Roure |first2=David |chapter=Turning numbers into notes |date=2015 |title=Ada Lovelace Symposium 2015- Celebrating 200 Years of a Computer Visionary on - Ada Lovelace Symposium '15 |chapter-url=http://dx.doi.org/10.1145/2867731.2867746 |___location=New York, New York, USA |publisher=ACM Press |pages=13 |doi=10.1145/2867731.2867746|isbn=978-1-4503-4150-9 }}</ref> Lovelace saw potential in computers to go beyond numerical calculations, predicting that they might one day generate complex musical compositions or perform tasks like language processing.<ref>{{Cite journal |last1=Haugtvedt |first1=Erica |last2=Abata |first2=Duane |title=Ada Lovelace: First Computer Programmer and Hacker? |url=http://dx.doi.org/10.18260/1-2--36646 |journal=2021 ASEE Virtual Annual Conference Content Access Proceedings |date=2021 |publisher=ASEE Conferences |doi=10.18260/1-2--36646}}</ref>
Though Babbage's designs were never fully realized due to technical and financial challenges, they influenced a range of subsequent developments in computing hardware. Notably, in the 1890s, [[Herman Hollerith]] adapted the idea of punched cards for automated data processing, which was utilized in the U.S. Census and sped up data tabulation significantly, bridging industrial machinery with data processing.<ref>{{Cite thesis |last=Blodgett |first=John H. |title=Herman Hollerith, data processing pioneer |date=1968 |publisher=Drexel University Libraries |doi=10.17918/00004750 |url=http://dx.doi.org/10.17918/00004750|url-access=subscription }}</ref>
The Industrial Revolution's advancements in mechanical systems demonstrated the potential for machines to conduct complex calculations, influencing engineers like [[Leonardo Torres Quevedo]] and [[Vannevar Bush]] in the early 20th century. Torres Quevedo designed an electromechanical machine with floating-point arithmetic,<ref>{{Citation |last=Torres y Quevedo |first=Leonardo |title=Essays on Automatics |date=1982 |work=The Origins of Digital Computers |pages=89–107 |url=http://dx.doi.org/10.1007/978-3-642-61812-3_6 |access-date=2024-10-30 |place=Berlin, Heidelberg |publisher=Springer Berlin Heidelberg |doi=10.1007/978-3-642-61812-3_6 |isbn=978-3-642-61814-7|url-access=subscription }}</ref> while Bush's later work explored electronic digital computing.<ref>{{Citation |title=6 Vannevar Bush, from "As We May Think" (1945) |date=2021 |work=Information |publisher=Columbia University Press |doi=10.7312/hayo18620-032 |isbn=978-0-231-54654-6|doi-access=free }}</ref> By the mid-20th century, these innovations paved the way for the first fully electronic computers.<ref>{{Cite book |last1=Haigh |first1=Thomas |url=http://dx.doi.org/10.7551/mitpress/11436.001.0001 |title=A New History of Modern Computing |last2=Ceruzzi |first2=Paul E. |date=2021-09-14 |publisher=The MIT Press |doi=10.7551/mitpress/11436.001.0001 |isbn=978-0-262-36648-9}}</ref>
==Analog computers==
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The first modern analog computer was a [[tide-predicting machine]], invented by [[Lord Kelvin|Sir William Thomson]], later Lord Kelvin, in 1872. It used a system of pulleys and wires to automatically calculate predicted tide levels for a set period at a particular ___location and was of great utility to navigation in shallow waters. His device was the foundation for further developments in analog computing.<ref name="stanf">{{cite encyclopedia |encyclopedia=Stanford Encyclopedia of Philosophy |title=The Modern History of Computing|year=2017 |publisher=Metaphysics Research Lab, Stanford University |url=https://plato.stanford.edu/entries/computing-history/ |access-date=2014-01-07 |archive-date=2010-07-12 |archive-url=https://web.archive.org/web/20100712072148/http://plato.stanford.edu/entries/computing-history/|url-status=live}}</ref>
The [[differential analyser]], a mechanical analog computer designed to solve differential equations by integration using wheel-and-disc mechanisms, was conceptualized in 1876 by [[James Thomson (engineer)|James Thomson]], the brother of the more famous Lord Kelvin. He explored the possible construction of such calculators, but was stymied by the limited output torque of the [[ball-and-disk integrator]]s.<ref>{{cite web |first=Ray |last=Girvan |title=The revealed grace of the mechanism: computing after Babbage |work=Scientific Computing World |date=May–June 2003 |url=https://www.scientific-computing.com/scwmayjun03computingmachines.html |archive-url=https://web.archive.org/web/20121103094710/http://www.scientific-computing.com/scwmayjun03computingmachines.html |archive-date=3 November 2012}}</ref> In a differential analyzer, the output of one integrator drove the input of the next integrator, or a graphing output.
A notable series of analog calculating machines were developed by [[Leonardo Torres Quevedo#Analogue calculating machines|Leonardo Torres Quevedo]] since 1895, including one that was able to compute the roots of arbitrary [[
[[File:US Army AF Drift Sight Mk. I on DH4.jpeg|thumb|left|A Mk. I Drift Sight. The lever just in front of the bomb aimer's fingertips sets the altitude, the wheels near his knuckles set the wind and airspeed.]]
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==Advent of the digital computer==
[[File:Women holding parts of the first four Army computers.jpg|right|thumb|Parts from four early computers, 1962. From left to right: [[ENIAC]] board, [[EDVAC]] board, [[ORDVAC]] board, and [[BRLESC]]-I board, showing the trend toward [[miniaturization]].]]
The principle of the modern computer was first described by
He also introduced the notion of a "universal machine" (now known as a [[universal Turing machine]]), with the idea that such a machine could perform the tasks of any other machine, or in other words, it is provably capable of computing anything that is computable by executing a program stored on tape, allowing the machine to be programmable. [[John von
===Electromechanical computers===
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The [[Z2 (computer)|Z2]] was one of the earliest examples of an electric operated digital [[computer]] built with electromechanical relays and was created by civil engineer [[Konrad Zuse]] in 1940 in Germany. It was an improvement on his earlier, mechanical [[Z1 (computer)|Z1]]; although it used the same mechanical [[computer memory|memory]], it replaced the arithmetic and control logic with electrical [[relay]] circuits.<ref name="Part 4 Zuse">{{cite web |url=https://www.epemag.com/zuse/part4a.htm|title=Part 4: Konrad Zuse's Z1 and Z3 Computers|last=Zuse|first=Horst |work=The Life and Work of Konrad Zuse|publisher=EPE Online |access-date=2008-06-17 |archive-url=https://web.archive.org/web/20080601210541/http://www.epemag.com/zuse/part4a.htm |archive-date = 2008-06-01}}</ref>
In the same year, electro-mechanical devices called [[bombe]]s were built by British [[cryptologist]]s to help decipher [[Germany|German]] [[Enigma machine|Enigma-machine]]-encrypted secret messages during [[World War II]]. The bombe's initial design was created in 1939 at the UK [[
[[File:Z3 Deutsches Museum.JPG|thumb|left|Replica of [[Konrad Zuse|Zuse]]'s [[Z3 (computer)|Z3]], the first fully automatic, digital (electromechanical) computer]]
In 1941, Zuse followed his earlier machine up with the [[Z3 (computer)|Z3]],<ref name="Part 4 Zuse"/> the world's first working [[electromechanical]] [[Computer programming|programmable]], fully automatic digital computer.<ref>{{cite news|title=A Computer Pioneer Rediscovered, 50 Years On |newspaper=The New York Times |url=https://www.nytimes.com/1994/04/20/news/20iht-zuse.html |date=20 April 1994 |access-date=2017-02-16 |archive-date=2016-11-04 |archive-url=https://web.archive.org/web/20161104051054/http://www.nytimes.com/1994/04/20/news/20iht-zuse.html|url-status=live}}</ref> The Z3 was built with 2000 [[relay]]s, implementing a 22-[[bit]] [[Word (computer architecture)|word length]] that operated at a [[clock rate|clock frequency]] of about 5–10 [[Hertz|Hz]].{{sfn|Zuse|1993|p=55}} Program code and data were stored on punched [[celluloid|film]]. It was quite similar to modern machines in some respects, pioneering numerous advances such as [[floating-point arithmetic|floating-point numbers]]. Replacement of the hard-to-implement decimal system (used in [[Charles Babbage]]'s earlier design) by the simpler [[binary number|binary]] system meant that Zuse's machines were easier to build and potentially more reliable, given the technologies available at that time.<ref>{{cite web |url=https://www.crash-it.com/crash/index.php?page=73 |archive-url=https://web.archive.org/web/20080318184915/http://www.crash-it.com/crash/index.php?page=73 |url-status=dead |archive-date=2008-03-18 |title=Zuse |work=Crash! The Story of IT}}</ref>
Zuse suffered setbacks during World War II when some of his machines were destroyed in the course of [[Allies of World War II|Allied]] bombing campaigns. Apparently his work remained largely unknown to engineers in the UK and US until much later, although at least IBM was aware of it as it financed his post-war startup company in 1946 in return for an option on Zuse's patents.
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The term digital was first suggested by [[George Stibitz|George Robert Stibitz]] and refers to where a signal, such as a voltage, is not used to directly represent a value (as it would be in an [[analog computer]]), but to encode it. In November 1937, Stibitz, then working at Bell Labs (1930–1941),<ref name=":0">{{cite web |title=Computer Pioneers – George Stibitz |url=https://history.computer.org/pioneers/stibitz.html |website=history.computer.org |access-date=2018-11-08 |archive-date=2018-10-05 |archive-url=https://web.archive.org/web/20181005004432/http://history.computer.org/pioneers/stibitz.html |url-status=live}}</ref> completed a relay-based calculator he later dubbed the "[[Model K (calculator)|Model K]]" (for "'''k'''itchen table", on which he had assembled it), which became the first [[binary adder]].<ref>{{cite book|last=Ritchie |first=David|date=1986|title=The Computer Pioneers|page=[https://archive.org/details/computerpioneers00ritc/page/35 35]|___location=New York|publisher=Simon and Schuster |isbn=067152397X|url=https://archive.org/details/computerpioneers00ritc}}</ref> Typically signals have two states – low (usually representing 0) and high (usually representing 1), but sometimes [[three-valued logic]] is used, especially in high-density memory. Modern computers generally use [[Boolean logic|binary logic]], but many early machines were [[decimal computer]]s. In these machines, the basic unit of data was the decimal digit, encoded in one of several schemes, including [[binary-coded decimal]] or BCD, [[Bi-quinary coded decimal|bi-quinary]], [[excess-3]], and [[two-out-of-five code]].
The mathematical basis of digital computing is [[Boolean algebra]], developed by the British mathematician [[George Boole]] in his work ''[[The Laws of Thought]]'', published in 1854. His Boolean algebra was further refined in the 1860s by [[William Jevons]] and [[Charles Sanders Peirce]], and was first presented systematically by [[Ernst Schröder (mathematician)|Ernst Schröder]] and [[A. N. Whitehead]].<ref name="DunnHardegree2001">{{cite book|first1=J. Michael|last1=Dunn|first2=Gary M.|last2=Hardegree|year=2001 |title=Algebraic methods in philosophical logic |url=https://books.google.com/books?id=-AokWhbILUIC&pg=PA2 |publisher=Oxford University Press US|isbn=978-0-19-853192-0|page=2|access-date=2016-06-04 |archive-date=2023-02-02 |archive-url=https://web.archive.org/web/20230202181643/https://books.google.com/books?id=-AokWhbILUIC&pg=PA2|url-status=live}}</ref> In 1879 Gottlob Frege
In the 1930s and working independently, American [[electronic engineer]] [[Claude Shannon]] and Soviet [[logician]] [[Victor Shestakov]] both showed a [[one-to-one correspondence]] between the concepts of [[Boolean logic]] and certain electrical circuits, now called [[logic gate]]s, which are now ubiquitous in digital computers.{{sfn|Shannon|1938}} They showed that electronic relays and switches can realize the [[expression (mathematics)|expression]]s of [[Boolean algebra (logic)|Boolean algebra]].{{sfn|Shannon|1940}} This thesis essentially founded practical [[digital circuit]] design. In addition Shannon's paper gives a correct circuit diagram for a 4 bit digital binary adder.{{sfn|Shannon|1938|pp=494–495|ps=.{{
===Electronic data processing===
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Colossus was the world's first [[electronics|electronic]] [[digital electronics|digital]] [[Computer programming|programmable]] [[computer]].<ref name="stanf" /> It used a large number of valves (vacuum tubes). It had paper-tape input and was capable of being configured to perform a variety of [[Boolean logic]]al operations on its data,<ref>{{Citation |last=Small |first=Albert W. |title=The Special Fish Report |publisher=The American National Archive (NARA) |___location=College Campus Washington |date=December 1944 |url=https://www.codesandciphers.org.uk/documents/small/smallix.htm |access-date=2019-01-11 |archive-date=2011-05-15 |archive-url=https://web.archive.org/web/20110515021436/http://www.codesandciphers.org.uk/documents/small/smallix.htm |url-status=live}}</ref> but it was not [[Turing-complete]]. Data input to Colossus was by [[photoelectric sensor|photoelectric]] reading of a paper tape transcription of the enciphered intercepted message. This was arranged in a continuous loop so that it could be read and re-read multiple times – there being no internal store for the data. The reading mechanism ran at 5,000 characters per second with the paper tape moving at {{cvt|40|ft/s|m/s mph|sigfig=3}}. Colossus Mark 1 contained 1500 thermionic valves (tubes), but Mark 2 with 2400 valves and five processors in parallel, was both 5 times faster and simpler to operate than Mark 1, greatly speeding the decoding process. Mark 2 was designed while Mark 1 was being constructed. [[Allen Coombs]] took over leadership of the Colossus Mark 2 project when [[Tommy Flowers]] moved on to other projects.<ref>{{Citation |last1=Randell |first1=Brian |author-link=Brian |last2=Fensom |first2=Harry |last3=Milne |first3=Frank A. |title=Obituary: Allen Coombs |newspaper=The Independent |date=15 March 1995 |url=https://www.independent.co.uk/news/people/obituary-allen-coombs-1611270.html |access-date=18 October 2012 |archive-date=2012-02-03 |archive-url=https://web.archive.org/web/20120203042657/http://www.independent.co.uk/news/people/obituary-allen-coombs-1611270.html |url-status=dead}}</ref> The first Mark 2 Colossus became operational on 1 June 1944, just in time for the Allied [[Invasion of Normandy]] on [[Normandy landings|D-Day]].
Most of the use of Colossus was in determining the start positions of the Tunny rotors for a message, which was called "wheel setting". Colossus included the first-ever use of [[shift register]]s and [[systolic array]]s, enabling five simultaneous tests, each involving up to 100 [[Boolean algebra|Boolean calculations]]. This enabled five different possible start positions to be examined for one transit of the paper tape.<ref>{{Citation |last=Flowers |first=T. H. |author-link=Tommy Flowers |title=The Design of Colossus |journal=Annals of the History of Computing |volume=5 |issue=3 |pages=239–252 |year=1983 |doi=10.1109/MAHC.1983.10079 |s2cid=39816473 |url=https://www.ivorcatt.com/47c.htm |access-date=2019-03-03 |archive-date=2006-03-26 |archive-url=https://web.archive.org/web/20060326041703/http://www.ivorcatt.com/47c.htm |url-status=live}}</ref> As well as wheel setting some later [[Colossus computer|Colossi]] included mechanisms intended to help determine pin patterns known as "wheel breaking". Both models were programmable using switches and plug panels in a way their predecessors had not been.
[[File:Glen Beck and Betty Snyder program the ENIAC in building 328 at the Ballistic Research Laboratory.jpg|thumb|[[ENIAC]] was the first Turing-complete electronic device, and performed ballistics trajectory calculations for the [[United States Army]].<ref>{{cite magazine |date=2014-11-25 |title=How the World's First Computer Was Rescued From the Scrap Heap |url=https://www.wired.com/2014/11/eniac-unearthed/ |first=Brendan I. |last=Loerner |magazine=Wired |access-date=2017-03-07 |archive-date=2017-05-02 |archive-url=https://web.archive.org/web/20170502064714/https://www.wired.com/2014/11/eniac-unearthed/ |url-status=live}}</ref>]]
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[[File:von Neumann architecture.svg|thumb|Design of the [[von Neumann architecture]], 1947]]
The theoretical basis for the stored-program computer was proposed by [[Alan Turing]] in his 1936 paper ''On Computable Numbers''.<ref name=Turing-1937-1938/> Whilst Turing was at [[Princeton University]] working on his PhD, [[John von Neumann]] got to know him and became intrigued by his concept of a universal computing machine.{{sfn|Copeland|2004|pp=21-22}}
Early computing machines executed the set sequence of steps, known as a '[[computer program|program]]', that could be altered by changing electrical connections using switches or a [[patch panel]] (or [[plugboard]]). However, this process of 'reprogramming' was often difficult and time-consuming, requiring engineers to create flowcharts and physically re-wire the machines.{{sfn|Copeland|2006|p=104}} Stored-program computers, by contrast, were designed to store a set of instructions (a [[computer program|program]]), in memory – typically the same memory as stored data.
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===EDVAC===
[[File:Edvac.jpg|right|thumb|upright|EDVAC]]
[[ENIAC]] inventors [[John Mauchly]] and [[J. Presper Eckert]] proposed the [[EDVAC]]'s construction in August 1944, and design work for the EDVAC commenced at the [[University of Pennsylvania]]'s [[Moore School of Electrical Engineering]], before the [[ENIAC]] was fully operational. The design implemented a number of important architectural and logical improvements conceived during the ENIAC's construction, and a high-speed [[Delay-line memory|serial-access memory]].<ref name="Wilkes
It was finally delivered to the [[United States Army|U.S. Army]]'s [[Ballistics Research Laboratory]] at the [[Aberdeen Proving Ground]] in August 1949, but due to a number of problems, the computer only began operation in 1951, and then only on a limited basis.
===Commercial computers===
The first commercial electronic computer was the [[Ferranti Mark 1]], built by [[Ferranti]] and delivered to the [[University of Manchester]] in February 1951. It was based on the [[Manchester Mark 1]]. The main improvements over the Manchester Mark 1 were in the size of the [[primary storage]] (using [[Random-access memory|random access]] [[Williams tubes]]), [[secondary storage]] (using a [[drum memory|magnetic drum]]), a faster multiplier, and additional instructions. The basic cycle time was 1.2 milliseconds, and a multiplication could be completed in about 2.16 milliseconds. The multiplier used almost a quarter of the machine's 4,050 vacuum tubes (valves).{{sfn|Lavington|1998|p=25}} A second machine was purchased by the [[University of Toronto]], before the design was revised into the [[Ferranti Mark 1#Mark 1 Star|Mark 1 Star]]. At least seven of these later machines were delivered between 1953 and 1957, one of them to [[Royal Dutch Shell|Shell]] labs in Amsterdam.<ref>{{Citation |publisher=Computer Conservation Society |title=Our Computer Heritage Pilot Study: Deliveries of Ferranti Mark I and Mark I Star computers. |url=https://www.ourcomputerheritage.org/wp/ |archive-url=https://web.archive.org/web/20161211201840/http://www.ourcomputerheritage.org/wp/ |url-status=dead |archive-date=11 December 2016 |access-date=9 January 2010 }}</ref>
In October 1947, the directors of [[J. Lyons and Co.|J. Lyons & Company]], a British catering company famous for its teashops but with strong interests in new office management techniques, decided to take an active role in promoting the commercial development of computers. The [[LEO computer|LEO I]] computer (Lyons Electronic Office) became operational in April 1951<ref>{{cite web | last = Lavington | first = Simon | title = A brief history of British computers: the first 25 years (1948–1973). | publisher = [[British Computer Society]] | url = http://www.bcs.org/server.php? | access-date = 10 January 2010 | archive-date = 2010-07-05 | archive-url = https://web.archive.org/web/20100705050757/http://www.bcs.org/server.php | url-status = dead }}</ref> and ran the world's first regular routine office computer [[job (software)|job]]. On 17 November 1951, the J. Lyons company began weekly operation of a bakery valuations job on the LEO – the first business [[:Category:Application software|application]] to go live on a stored-program computer.{{efn|{{harvnb|Martin|2008|p=24}} notes that [[David Caminer]] (1915–2008) served as the first corporate electronic systems analyst, for this first business computer system. LEO would calculate an employee's pay, handle billing, and other office automation tasks.}}
In June 1951, the [[UNIVAC I]] (Universal Automatic Computer) was delivered to the [[United States Census Bureau|U.S. Census Bureau]]. Remington Rand eventually sold 46 machines at more than {{US$|1 million}} each (${{Formatprice|{{Inflation|US|1000000|1951|r=-4}}|0}} as of {{
In 1952, [[Groupe Bull|Compagnie des Machines Bull]] released the [[Bull Gamma 3|Gamma 3]] computer, which became a large success in Europe, eventually selling more than 1,200 units, and the first computer produced in more than 1,000 units.<ref name=":1">{{Cite journal |last=Leclerc |first=Bruno |date=January 1990 |title=From Gamma 2 to Gamma E.T.: The Birth of Electronic Computing at Bull
[[File:IBM-650-panel.jpg|thumb|right|Front panel of the [[IBM 650]] ]]
Compared to the UNIVAC, IBM introduced a smaller, more affordable computer in 1954 that proved very popular.{{efn|For example, Kara Platoni's article on [[Donald Knuth]] stated that "there was something special about the IBM 650".<ref>{{cite magazine |first=Kara |last=Platoni |title=Love at First Byte |magazine=Stanford Magazine |url=https://www.stanfordalumni.org/news/magazine/2006/mayjun/features/knuth.html |date=May–June 2006 |archive-url= https://web.archive.org/web/20060925022700/http://www.stanfordalumni.org/news/magazine/2006/mayjun/features/knuth.html |archive-date=2006-09-25 |url-status=dead}}</ref>}}<ref>
V. M. Wolontis (18 August 1955) "A Complete Floating-Decimal Interpretive System for the I.B.M. 650 Magnetic Drum Calculator—Case 20878" Bell Telephone Laboratories Technical Memorandum MM-114-37, Reported in IBM Technical Newsletter No. 11, March 1956, as referenced in {{cite journal |title=Wolontis-Bell Interpreter |publisher=IEEE |journal=Annals of the History of Computing |volume=8 |issue=1 |date=January–March 1986 |pages=74–76 |doi=10.1109/MAHC.1986.10008 |s2cid=36692260}}
</ref> The [[IBM 650]] weighed over {{val|900|u=kg}}, the attached power supply weighed around {{val|1350|u=kg}} and both were held in separate cabinets of roughly 1.5{{times}}0.9{{times}}{{val|1.8|u=meters}}. The system cost {{US$|500000}}<ref>{{cite book |last=Dudley |first=Leonard |title=Information Revolution in the History of the West |year=2008 |url= https://books.google.com/books?id=jLnPi5aYoJUC&pg=PA266 |isbn=978-1-84720-790-6 |publisher=Edward Elgar Publishing |page=266 |access-date=2020-08-30}}</ref> (${{Formatprice|{{Inflation|US|500000|1954|r=-4}}|0}} as of {{
===Microprogramming===
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At the [[University of Manchester]], a team under the leadership of [[Tom Kilburn]] designed and built a machine using the newly developed [[transistor]]s instead of valves. Initially the only devices available were [[germanium]] [[point-contact transistor]]s, less reliable than the valves they replaced but which consumed far less power.{{sfn|Lavington|1998|pp=34–35}} Their first [[transistor computer|transistorized computer]], and the first in the world, was [[Manchester computers#Transistor Computer|operational by 1953]],{{sfn|Lavington|1998|p=37}} and a second version was completed there in April 1955.{{sfn|Lavington|1998|p=37}} The 1955 version used 200 transistors, 1,300 [[Solid-state electronics|solid-state]] [[diode]]s, and had a power consumption of 150 watts. However, the machine did make use of valves to generate its 125 kHz clock waveforms and in the circuitry to read and write on its magnetic drum memory, so it was not the first completely transistorized computer.
That distinction goes to the [[Harwell CADET]] of 1955,<ref name="ieeexplore.ieee"/> built by the electronics division of the [[Atomic Energy Research Establishment]] at [[Harwell, Oxfordshire|Harwell]]. The design featured a 64-kilobyte magnetic drum memory store with multiple moving heads that had been designed at the [[National Physical Laboratory (United Kingdom)|National Physical Laboratory, UK]]. By 1953 this team had transistor circuits operating to read and write on a smaller magnetic drum from the [[Royal Radar Establishment]]. The machine used a low clock speed of only 58 kHz to avoid having to use any valves to generate the clock waveforms.<ref>{{cite book |last=Cooke-Yarborough |first=E.H. |title=Introduction to Transistor Circuits |publisher=Oliver and Boyd |year=1957 |___location=Edinburgh}}</ref><ref name="ieeexplore.ieee">{{cite journal| title=Some early transistor applications in the UK| journal=Engineering Science & Education Journal| volume=7| issue=3| pages=100–106| year=1998| last1=Cooke-Yarborough| first1=E.H.| doi=10.1049/esej:19980301| doi-broken-date=12 July 2025}}</ref>
CADET used 324-point-contact transistors provided by the UK company [[Standard Telephones and Cables]]; 76 [[Bipolar junction transistor|junction transistor]]s were used for the first stage amplifiers for data read from the drum, since point-contact transistors were too noisy. From August 1956, CADET was offering a regular computing service, during which it often executed continuous computing runs of 80 hours or more.<ref>{{cite book |last=Lavington |first=Simon |title=Early British Computers |publisher=Manchester University Press |year=1980 |url=https://ed-thelen.org/comp-hist/EarlyBritish-05-12.html#Ch-09 |isbn=0-7190-0803-4 |access-date=2014-01-07 |archive-date=2019-05-24 |archive-url=https://web.archive.org/web/20190524164254/http://ed-thelen.org/comp-hist/EarlyBritish-05-12.html#Ch-09 |url-status=live }}</ref><ref>{{Cite journal |doi= 10.1049/pi-b-1.1956.0076 |title=A transistor digital computer |journal=Proceedings of the IEE - Part B: Radio and Electronic Engineering |volume=103 |issue=3S |pages=364–370 |year=1956 |last1=Cooke-Yarborough |first1=E.H. |last2= Barnes |first2=R.C.M. |last3=Stephen |first3=J.H. |last4=Howells |first4=G.A.}}</ref> Problems with the reliability of early batches of point contact and alloyed junction transistors meant that the machine's [[mean time between failures]] was about 90 minutes, but this improved once the more reliable [[bipolar junction transistor]]s became available.{{sfn|Lavington|1998|pp=36–37}}
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[[File:Altair 8800 Computer.jpg|right|thumb|Altair 8800]]
While which specific product is considered the first microcomputer system is a matter of debate, one of the earliest is R2E's [[Micral#
In April 1975, at the [[Hannover Messe|Hannover Fair]], [[Olivetti]] presented the [[Olivetti P6060|P6060]], the world's first complete, pre-assembled personal computer system. The central processing unit consisted of two cards, code named PUCE1 and PUCE2, and unlike most other personal computers was built with [[Transistor–transistor logic|TTL]] components rather than a microprocessor. It had one or two 8" [[floppy disk]] drives, a 32-character [[plasma display]], 80-column graphical [[thermal printer]], 48 Kbytes of [[random-access memory|RAM]], and [[BASIC]] language. It weighed {{cvt|40|kg|lb}}. As a complete system, this was a significant step from the Altair, though it never achieved the same success. It was in competition with a similar product by IBM that had an external floppy disk drive.
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From 1975 to 1977, most microcomputers, such as the [[KIM-1|MOS Technology KIM-1]], the [[Altair 8800]], and some versions of the [[Apple I]], were sold as kits for do-it-yourselfers. Pre-assembled systems did not gain much ground until 1977, with the introduction of the [[Apple II]], the Tandy [[TRS-80]], the first [[SWTPC]] computers, and the [[Commodore PET]]. Computing has evolved with microcomputer architectures, with features added from their larger brethren, now dominant in most market segments.
A NeXT Computer and its [[Object-oriented programming|object-oriented]] development tools and libraries were used by [[Tim Berners-Lee]] and [[Robert Cailliau]] at [[CERN]] to develop the world's first [[web server]] software, [[CERN httpd]], and also used to write the first [[web browser]], [[WorldWideWeb]].
Systems as complicated as computers require very high [[reliability engineering|reliability]]. ENIAC remained on, in continuous operation from 1947 to 1955, for eight years before being shut down. Although a vacuum tube might fail, it would be replaced without bringing down the system. By the simple strategy of never shutting down ENIAC, the failures were dramatically reduced. The vacuum-tube [[Semi-Automatic Ground Environment|SAGE]] air-defense computers became remarkably reliable – installed in pairs, one off-line, tubes likely to fail did so when the computer was intentionally run at reduced power to find them. [[Hot plugging|Hot-pluggable]] hard disks, like the hot-pluggable vacuum tubes of yesteryear, continue the tradition of repair during continuous operation. Semiconductor memories routinely have no errors when they operate, although operating systems like Unix have employed memory tests on start-up to detect failing hardware. Today, the requirement of reliable performance is made even more stringent when [[server farm]]s are the delivery platform.<ref>{{cite web |last=Shankland |first=Stephen |title=Google uncloaks once-secret server |website=
In the 21st century, [[multi-core]] CPUs became commercially available.<ref>{{cite web |last=Shrout |first=Ryan |date=2 December 2009 |website=PC Perspective |url=https://pcper.com/2009/12/intel-shows-48-core-x86-processor-as-single-chip-cloud-computer/ |title=Intel Shows 48-core x86 Processor as Single-chip Cloud Computer|archive-url=https://web.archive.org/web/20100814203128/http://www.pcper.com/article.php?aid=825 |archive-date=2010-08-14 |url-status=live |access-date=2020-12-02}}<br/>{{*}}{{cite web |date=3 December 2009 |title=Intel unveils 48-core cloud computing silicon chip |work=BBC News |url=https://news.bbc.co.uk/2/hi/technology/8392392.stm |access-date=2009-12-03 |archive-date=2012-12-06 |archive-url=https://web.archive.org/web/20121206054225/http://news.bbc.co.uk/2/hi/technology/8392392.stm |url-status=live}}</ref> [[Content-addressable memory]] (CAM){{sfn|Kohonen|1980|p={{
CMOS circuits have allowed computing to become a commercial [[
{{anchor|quantum computing}}[[Quantum computing]] is an emerging technology in the field of computing. ''MIT Technology Review'' reported 10 November 2017 that IBM has created a 50-[[qubit]] computer; currently its quantum state lasts 50 microseconds.<ref>{{cite web |url=https://www.technologyreview.com/s/609451/ibm-raises-the-bar-with-a-50-qubit-quantum-computer/ |first=Will |last=Knight |work=MIT Technology Review |date=10 November 2017 |title=IBM Raises the Bar with a 50-Qubit Quantum Computer |access-date=2017-11-10 |url-status=live |archive-date=2017-11-
Computing hardware and its software have even become a metaphor for the operation of the universe.<ref>{{harvnb|Smolin|2001|pp=53–57}}. Pages 220–226 are annotated references and guide for further reading.</ref>
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* [[History of personal computers]]
* [[History of software]]
* {{Annotated link|History of supercomputing}}
* [[Information Age]]
* [[IT History Society]]
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|title = ENIAC: The Army-Sponsored Revolution
|date = January 1996
|url =
|access-date = 2008-05-17
|url-status =
|archive-url = https://web.archive.org/web/20070716132201/http://ftp.arl.army.mil/~mike/comphist/96summary/
|archive-date = 2007-07-16
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|archive-date = 2007-10-24
}}
* {{Citation |last=Randell |first=Brian |author-link=Brian Randell |editor-last=Metropolis |editor-first=N. |editor-link=Nicholas Metropolis |editor2-last=Howlett |editor2-first=J. |editor2-link=Jack Howlett |editor3-last=Rota |editor3-first=Gian-Carlo |editor3-link=Gian-Carlo Rota |title=A History of Computing in the Twentieth Century |chapter=The Colossus |pages=47–92 |year=1980 |publisher=Elsevier Science |isbn=978-0124916500 |chapter-url=https://archive.org/details/historyofcomputi0000inte/page/47 }}
* {{Citation
| last = Reynolds
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==External links==
{{Wikiversity|Introduction to Computers/History}}
{{
*[https://www.oldcomputers.net/ Obsolete Technology – Old Computers]
*[https://meta-studies.net/pmwiki/pmwiki.php?n=Site.Introduction ''Things That Count'']
| |||