The history of computing hardware covers the developments from early simple devices to aid calculation to modern day computers. Before the 20th century, most calculations were done by humans. Early mechanical tools to help humans with digital calculations, such as the abacus, were called "calculating machines", by proprietary names, or even as they are now, calculators. The machine operator was called the computer.

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. Later, computers represented numbers in a continuous form, for instance distance along a scale, rotation of a shaft, or a voltage. Numbers could also be represented in the form of digits, automatically manipulated by a mechanical mechanism. Although this approach generally required more complex mechanisms, it greatly increased the precision of results. A series of breakthroughs, such as digital circuits, miniaturized transistor computers, transistorized stored-program computers, and the integrated circuit, caused digital computers to largely replace analog computers. Following developments such as the microprocessor, the cost of computers gradually became so low that, by the 1990s, personal computers, and then, in the 2000s and 2010s, mobile computers (smartphones and tablets), became ubiquitous in industrialized countries.

Early devicesEdit

Ancient eraEdit

Devices have been used to aid computation for thousands of years, mostly using one-to-one correspondence with fingers. The earliest counting device was probably a form of tally stick. 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.[1][2][3] 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 2400 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 computers were constructed in ancient and medieval times to perform astronomical calculations. These included the south-pointing chariot (c. 1000–900 BC) from ancient China, and the astrolabe and Antikythera mechanism from the Hellenistic world (c. 150–100 BC).[4] The Egyptian/Phoenician mathematician Hero of Alexandria (c. 10–70 AD) made mechanical devices including automata and a programmable cart.[5] Other early mechanical devices used to perform one or another type of calculations include the planisphere and other mechanical computing devices invented by Abu Rayhan al-Biruni (c. AD 1000); the equatorium and universal latitude-independent astrolabe by Abu Ishaq Ibrahim al-Zarqali (c. AD 1015); the astronomical analog computers of other medieval Muslim astronomers and engineers; and the astronomical clock tower of Su Song (c. AD 1090) during the Song dynasty. The castle clock, a hydropowered mechanical astronomical clock invented by Al-Jazari in 1206, was the first programmable analog computer.[6][7][8]


Main article: Calculator

By the 20th century, earlier mechanical calculators, cash registers, accounting machines, and so on were redesigned to use electric motors, with gear position as the representation for the state of a variable. The word "computer" was a job title assigned to people who used these calculators to perform mathematical calculations

The world's first all-electric desktop calculator was the Japanese Casio Computer Company's Model 14-A calculator, released in 1957,[9] based on relay technology.[10]

In 1965, dynamic RAM (DRAM) was introduced by Toshiba's Toscal BC-1411 desktop calculator. It used a form of dynamic RAM built from discrete components.[11] Casio's AL-1000 was an early electronic programmable calculator, released in 1967.[12]

Japan's Sharp Corporation introduced portable calculator technology. In 1969, the Sharp QT-8D was the first mass-produced calculator to have its logic circuitry entirely implemented with LSI ICs based on MOS technology.[13][14] Upon its introduction,[15] it was one of the smallest electronic calculators ever produced commercially. In 1970, the Sharp EL-8 was the first battery-powered, handheld calculator.[16][17]

Analog computersEdit

Main article: Analog computer

In the first half of the 20th century, analog computers were considered by many to be the future of computing. These devices used the continuously changeable aspects of physical phenomena such as electrical, mechanical, or hydraulic quantities to model the problem being solved, in contrast to digital computers that represented varying quantities symbolically, as their numerical values change. As an analog computer does not use discrete values, but rather continuous values, processes cannot be reliably repeated with exact equivalence, as they can with Turing machines.[18]

By the 1950s the success of digital electronic computers had spelled the end for most analog computing machines, but hybrid analog computers, controlled by digital electronics, remained in substantial use into the 1950s and 1960s, and later in some specialized applications.

Electromechanical computersEdit

The era of modern computing began with a flurry of development before and during World War II. Most digital computers built in this period were electromechanical - electric switches drove mechanical relays to perform the calculation. These devices had a low operating speed and were eventually superseded by much faster all-electric computers, originally using vacuum tubes.

Digital computationEdit

A mathematical basis of digital computing is Boolean algebra. In the 1930s, Japanese NEC engineer Akira Nakashima introduced switching circuit theory. In a series of papers published from 1934 to 1936, he formulated a two-valued Boolean algebra, which he discovered independently, as a way to analyze and design circuits by algebraic means.[19][20][21][22] Nakashima's work laid the foundations for digital circuit design.[22]

Stored-program computerEdit

Early computing machines had fixed programs. For example, a desk calculator is a fixed program computer. It can do basic mathematics, but it cannot be used as a word processor or a gaming console. Changing the program of a fixed-program machine requires re-wiring, re-structuring, or re-designing the machine. The earliest computers were not so much "programmed" as they were "designed". "Reprogramming", when it was possible at all, was a laborious process, starting with flowcharts and paper notes, followed by detailed engineering designs, and then the often-arduous process of physically re-wiring and re-building the machine.[23] With the proposal of the stored-program computer, this changed. A stored-program computer includes by design an instruction set and can store in memory a set of instructions (a program) that details the computation.

Early stored-program computers were initially not transistorized. The first stored-program transistor computer was the ETL Mark III, developed by Japan's Electrotechnical Laboratory.[24][25][26] It began development in 1954,[27] and was completed in 1956.[25]


Microprogramming was used in the CPUs and floating-point units of mainframe and other computers; it was implemented for the first time in EDSAC 2 (1958),[28] which also used multiple identical "bit slices" to simplify design. Interchangeable, replaceable tube assemblies were used for each bit of the processor.[29]

The use of programming in electronic transistor computers was introduced in 1961, with the KT-Pilot, developed by Kyoto University and Toshiba in Japan.[24][30]

Transistor computersEdit

The bipolar transistor was invented in 1947. From 1955 onwards, transistors replaced vacuum tubes in computer designs,[31] giving rise to the "second generation" of computers. Initially the only devices available were germanium point-contact transistors.[32] Compared to vacuum tubes, transistors have many advantages: they are smaller, and require less power than vacuum tubes, so give off less heat. Silicon junction transistors were much more reliable than vacuum tubes and had longer, indefinite, service life. Transistorized computers could contain tens of thousands of binary logic circuits in a relatively compact space. Transistors greatly reduced computers' size, initial cost, and operating cost.

At the University of Manchester, a team under the leadership of Tom Kilburn designed and built a machine using the newly developed transistors instead of valves. Initially the only devices available were germanium point-contact transistors, less reliable than the valves they replaced but which consumed far less power.Template:Sfnp Their first transistorised computer and the first in the world, was operational by 1953,[33] and a second version was completed there in April 1955.Template:Sfnp The 1955 version used 200 transistors, 1,300 solid-state diodes, 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.

Early transistor computers were initially not stored-program computers. The first transistorized stored-program computer was the ETL Mark III, developed by Japan's Electrotechnical Laboratory.[24][25][26] It began development in 1954,[27] and was completed in 1956.[25]

Integrated circuitEdit

The next great advance in computing power came with the advent of the integrated circuit. The first practical ICs were invented by Jack Kilby at Texas Instruments and Robert Noyce at Fairchild Semiconductor.[34] Kilby recorded his initial ideas concerning the integrated circuit in July 1958, successfully demonstrating the first working integrated example on 12 September 1958.[35] In his patent application of 6 February 1959, Kilby described his new device as “a body of semiconductor material ... wherein all the components of the electronic circuit are completely integrated.”[36]

Noyce also came up with his own idea of an integrated circuit half a year later than Kilby.[37] His chip solved many practical problems that Kilby's had not. Produced at Fairchild Semiconductor, it was made of silicon, whereas Kilby's chip was made of germanium.



File:Intel 8742 153056995.jpg

The explosion in the use of computers began with "third-generation" computers, making use of Jack St. Clair Kilby's and Robert Noyce's independent invention of the integrated circuit (or microchip), which eventually led to the invention of the microprocessor. It is largely undisputed that the first single-chip microprocessor was the Intel 4004.[38] It originated in Japan with the "Busicom Project"[39] as Masatoshi Shima's three-chip CPU design in 1968,[40][39] before Sharp's Tadashi Sasaki conceived of a single-chip microprocessor, which he discussed with Busicom and Intel in 1968.[41] The Intel 4004 was then designed and realized as a single-chip microprocessor from 1969 to 1970, by Busicom's Masatoshi Shima and Intel's Ted Hoff and Federico Faggin.

While the earliest microprocessor ICs literally contained only the processor, i.e. the central processing unit, of a computer, their progressive development naturally led to chips containing most or all of the internal electronic parts of a computer. The integrated circuit in the image on the right, for example, an Intel 8742, is an 8-bit microcontroller that includes a CPU running at 12 MHz, 128 bytes of RAM, 2048 bytes of EPROM, and I/O in the same chip.

The first single-chip 16-bit microprocessor was introduced in 1975. Panafacom, a conglomerate formed by Japanese companies Fujitsu, Fuji Electric, and Matsushita, introduced the MN1610, a commercial 16-bit microprocessor.[42][43][44] According to Fujitsu, it was "the world's first 16-bit microcomputer on a single chip".[43]

During the 1960s, there was considerable overlap between second and third generation technologies.[45] IBM implemented its IBM Solid Logic Technology modules in hybrid circuits for the IBM System/360 in 1964. As late as 1975, Sperry Univac continued the manufacture of second-generation machines such as the UNIVAC 494. The Burroughs large systems such as the B5000 were stack machines, which allowed for simpler programming. These pushdown automatons were also implemented in minicomputers and microprocessors later, which influenced programming language design. Minicomputers served as low-cost computer centers for industry, business and universities.[46] It became possible to simulate analog circuits with the simulation program with integrated circuit emphasis, or SPICE (1971) on minicomputers, one of the programs for electronic design automation (EDA).


The microprocessor led to the development of the microcomputer, which are small, low-cost computers that could be owned by individuals and small businesses. Microcomputers, the first of which appeared in the 1970s, became ubiquitous in the 1980s and beyond. The first microcomputer was Japan's Sord SMP80/08, developed in April 1972.[47] It was soon followed by several other unique hobbyist systems developed based on the Intel 4004 and its successor, the Intel 8008. The first commercially available microcomputer kits were based on the Intel 8080: the Sord SMP80/x series, released in May 1974,[47] and the Altair 8800, which was announced in the January 1975 cover article of Popular Electronics. However, the Altair 8800 was an extremely limited system in its initial stages, having only 256 bytes of DRAM in its initial package and no input-output except its toggle switches and LED register display. Despite this, it was initially surprisingly popular, with several hundred sales in the first year, and demand rapidly outstripped supply. Several early third-party vendors such as Cromemco and Processor Technology soon began supplying additional S-100 bus hardware for the Altair 8800.

In April 1975 at the Hannover Fair, Olivetti presented the P6060, the 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 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 RAM, and BASIC language. It weighed 40 kg (Bad rounding hereScript error 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.

From 1975 to 1977, most microcomputers, such as the 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 home computers: the Apple II, Tandy TRS-80, Sord M200,[48] and Commodore PET. Computing has evolved with microcomputer architectures, with features added from their larger brethren, now dominant in most market segments.

See alsoEdit


  1. According to 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 4000 years Template:Webarchive) 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.
  2. Robson, Eleanor (2008), Mathematics in Ancient Iraq, ISBN 978-0-691-09182-2 . p.5: 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.
  3. Robson has recommended at least one supplement to Schmandt-Besserat, e.g., a review Englund, R. (1993) "The origins of script" Science 260, 1670-1671
  4. Lazos 1994
  5. Noel Sharkey (July 4, 2007), A programmable robot from 60 AD, 2611, New Scientist, 
  6. "Episode 11: Ancient Robots", Ancient Discoveries (History Channel),, retrieved 2008-09-06 
  7. Howard R. Turner (1997), Science in Medieval Islam: An Illustrated Introduction, p. 184, University of Texas Press, ISBN 0-292-78149-0
  8. Donald Routledge Hill, "Mechanical Engineering in the Medieval Near East", Scientific American, May 1991, pp. 64–9 (cf. Donald Routledge Hill, Mechanical Engineering)
  11. Toshiba "Toscal" BC-1411 Desktop Calculator
  13. Rick Bensene. Sharp QT-8D Electronic Calculator. The Old Calculator Web Museum. Retrieved on September 29, 2010.
  14. Sharp History — 1969–1970: From Senri to Tenri. SHARP World. Sharp Corporation. Retrieved on September 30, 2010.
  15. Nigel Tout. Sharp QT-8D "micro Compet". Vintage Calculators Web Museum. Retrieved on September 29, 2010.
  16. Joerg Woerner. Sharp EL-8. Datamath Calculator Museum. Retrieved on October 8, 2010.
  17. John Wolff. Sharp EL-8 and EL-8M Portable Calculators. John Wolff's Web Museum. Retrieved on July 30, 2014.
  18. Chua 1971, pp. 507–519
  19. History of Research on Switching Theory in Japan, IEEJ Transactions on Fundamentals and Materials, Vol. 124 (2004) No. 8, pp. 720-726, Institute of Electrical Engineers of Japan
  20. Switching Theory/Relay Circuit Network Theory/Theory of Logical Mathematics, IPSJ Computer Museum, Information Processing Society of Japan
  21. Radomir S. Stanković (University of Niš), Jaakko T. Astola (Tampere University of Technology), Mark G. Karpovsky (Boston University), Some Historical Remarks on Switching Theory, 2007, DOI
  22. 22.0 22.1 Radomir S. Stanković, Jaakko Astola (2008), Reprints from the Early Days of Information Sciences: TICSP Series On the Contributions of Akira Nakashima to Switching Theory, TICSP Series #40, Tampere International Center for Signal Processing, Tampere University of Technology
  23. Copeland 2006, p. 104
  24. 24.0 24.1 24.2 Early Computers, Information Processing Society of Japan
  25. 25.0 25.1 25.2 25.3 【Electrotechnical Laboratory】 ETL Mark III Transistor-Based Computer, Information Processing Society of Japan
  26. 26.0 26.1 Early Computers: Brief History, Information Processing Society of Japan
  27. 27.0 27.1 Martin Fransman (1993), The Market and Beyond: Cooperation and Competition in Information Technology, page 19, Cambridge University Press
  28. Wilkes, M. V. (1992). "Edsac 2". IEEE Annals of the History of Computing 14 (4): 49–56. Error: Bad DOI specified. 
  29. The microcode was implemented as extracode on Atlas accessdate=20100209
  30. 【Kyoto University,Toshiba】 KT-Pilot, Information Processing Society of Japan
  31. Feynman, Leighton & Sands 1966, pp. 14-11 to 14–12
  32. Lavington 1998, pp. 34–35
  33. Lavington 1998, p. 37
  34. Kilby 2000
  35. The Chip that Jack Built, (c. 2008), (HTML), Texas Instruments, Retrieved 29 May 2008.
  36. Winston, Brian (1998). Media Technology and Society: A History : From the Telegraph to the Internet. Routledge. p. 221. ISBN 978-0-415-14230-4. 
  37. Robert Noyce's Unitary circuit, Template:Ref patent
  38. Intel_4004 1971
  39. 39.0 39.1 Federico Faggin, The Making of the First Microprocessor, IEEE Solid-State Circuits Magazine, Winter 2009, IEEE Xplore
  40. Nigel Tout. The Busicom 141-PF calculator and the Intel 4004 microprocessor. Retrieved on November 15, 2009.
  41. Aspray, William (1994-05-25). Oral-History: Tadashi Sasaki. Interview #211 for the Center for the History of Electrical Engineering. The Institute of Electrical and Electronics Engineers, Inc.. Retrieved on 2013-01-02.
  42. 16-bit Microprocessors. CPU Museum. Retrieved on 5 October 2010.
  43. Cite error: Invalid <ref> tag; no text was provided for refs named fujitsu
  44. PANAFACOM Lkit-16, Information Processing Society of Japan
  45. In the defense field, considerable work was done in the computerized implementation of equations such as Kalman 1960, pp. 35–45
  46. Eckhouse & Morris 1979, pp. 1–2
  47. 47.0 47.1 【Sord】 SMP80/x series, Information Processing Society of Japan
  48. 【Sord】 M200 Smart Home Computer Series, Information Processing Society of Japan




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