From Cave Paintings to the Internet A Chronological and Thematic Database on the History of Information and Media Computer & Calculator Design / Architecture Timeline

Abū al-'Iz Ibn Ismā'īl ibn al-Razāz al-Jazarī builds a his castle clock, a most sophisticated water-powered astronomical clock, which has been called the earliest programmable analog computer. 

"It was a complex device that was about 11 feet high, and had multiple functions alongside timekeeping. It included a display of the zodiac and the solar and lunar orbits, and a pointer in the shape of the crescent moon which travelled across the top of a gateway, moved by a hidden cart and causing automatic doors to open, each revealing a mannequin, every hour. It was possible to re-program the length of day and night everyday in order to account for the changing lengths of day and night throughout the year, and it also featured five robotic musicians who automatically play[ed] music when moved by levers operated by a hidden camshaft attached to a water wheel. Other components of the castle clock included a main reservoir with a float, a float chamber and flow regulator, plate and valve trough, two pulleys, crescent disc displaying the zodiac, and two falcon automata dropping balls into vases" (Wikipedia article on Al-Jazari, accessed 04-02-2009).

Mathematician and philosopher Blaise Pascal invents an adding machine, the Pascaline.

In 1645 Pascal published an eighteen-page pamphlet describing his calculating machine. It was called Lettre dédicatoire à Monseigneur le Chancelier sur le sujet de la machine nouvellement inventée par le Sieur B. P. pour faire toutes sortes d’opérations d’arithmétique, par un mouvement reglé, sans plume ny jettons avec un advis necessaire à ceux qui auront curiosité de voir ladite machine. . . . The pamphlet does not identify a place of printing or a printer’s name, so we may assume that Pascal paid for its printing. When we published Origins of Cyberspace OCLC cited only two copies of this pamphlet in one French library and no copies in North America.

Pascal's pamphlet was reprinted along with additional material related to the Pascaline in his Oeuvres (1779), vol. 4, 7-30. The additional material consisted of Pascal's 1650 letter describing the machine that he presented to Queen Christina of Sweden; the privilege for its construction and sale issued in 1649, and Denis Diderot's description of the machine published in the Encyclopédie.

Hook & Norman, Origins of Cyberspace (2002) no. 13.

Gottfried Wilhelm Leibniz makes a drawing of his calculating machine mechanism.

Using a stepped drum, the Leibniz Stepped Reckoner, or step reckoner, mechanized multiplication as well as addition by performing repetitive additions. Leibniz had only a wooden model and two brass examples of the machine constructed. These would have been seen by relatively few people. However, because of descriptions published from 1710 onward, the machine was well-enough known to have great influence. The stepped-drum gear was the only workable solution to certain calculating machine problems until about 1875.

Leibniz first published a brief illustrated description of his machine in "Brevis descriptio machinae arithmeticae, cum figura. . . ," Miscellanea Berolensia ad incrementum scientiarum (1710) 317-19, figure 73. The lower portion of the frontispiece of the journal volume also shows a a tiny model of Leibniz's calculator.

"Leibniz got the idea for a calculating machine in 1672 in Paris, from a pedometer. Later he learned about Pascal's machine when he read Pascal's Pensées. He concentrated on expanding Pascal's mechanism so it could multiply and divide. He presented a wooden model to the Royal Society of London on February 1, 1673, and received much encouragement. In a letter of March 26, 1673 to Johann Friedrich, where he mentioned the presentation in London, Leibniz described the purpose of the "arithmetic machine" as making calculations "leicht, geschwind, gewiß" [sic], i.e. easy, fast, and reliable. Leibniz also added that theoretically the numbers calculated might be as large as desired, if the size of the machine was adjusted; quote: "eine zahl von einer ganzen Reihe Ziphern, sie sey so lang sie wolle (nach proportion der größe der Machine)" [sic]. In English: "a number consisting of a series of figures, as long as it may be (in proportion to the size of the machine)". His first preliminary brass machine was built 1674 - 1685. His so-called 'older machine' was built 1686 - 1694. The 'younger machine', the surviving machine, was built from 1690 to 1720.

"In 1775 the 'younger machine' was sent to Göttingen University for repair, and was forgotten. In 1876 a crew of workmen found it in an attic room of a Göttingen University building. It was returned to Hannover in 1880. In 1894-1896 Artur Burkhardt, founder of a major German calculator company restored it, and it has been kept in the Niedersaächsischen Landesbibliothek ever since" (Wikipedia article on Stepped Reckoner, accessed 05-25-2009).

Tomash & Williams, The Erwin Tomash Library on the History of Computing (2009) L69 (p. 772-73).

A dated manuscript by Gottfried Wilhelm Leibniz, preserved in the Niedersachsische Landesbibliothek, Hannover, “includes a brief discussion of the possibility of designing a mechanical binary calculator which would use moving balls to represent binary digits.”

Though Leibniz thought of the application of binary arithmetic to computing in 1679, the machine he outlined was never built, and he published nothing on the subject until his Explication de l'arithmétique binaire, qui se sert des seuls caracteres 0 & 1; avec des remarques sur son utilité, & sur ce qu'elle donne le sens des anciens figues Chinoises de Fohy' published in Histoire de l'Académie Royale des Sciences année MDCCIII. Avec les mémoires de mathématiques which appeared in print in 1705.

"The publication of the Explication was prompted by Leibniz's correspondence with Joachim Bouvet, a member of the Jesuit Mission in China. Leibniz had developed an interest in China, and in April 1697 he edited a collection of letters and essays by members of the Mission, entitled Novissima Sinica. A copy of this came into the hands of Bouvet, who wrote to Leibniz on 18 October 1697 expressing his commendation of the work. Thus began an extended correspondence between the two men which proved to be very important for the dissemination of Leibniz's ideas about binary arithmetic. The crucial exchange began on 15 February 1701, when Leibniz wrote to Bouvet describing for his correspondent the principles of his binary arithmetic, including the analogy of the formation of all the numbers from 0 and 1 with the creation of the world by God out of nothing. Bouvet immediately recognised the relationship between the hexagrams of the I ching and the binary numbers and he communicated his discovery in a letter written in Peking on 4 November 1701. This reached Leibniz, after a detour through England, on 1 April 1703. With this letter, Bouvet enclosed a woodcut of the arrangement of the hexagrams attributed to Fu-Hsi, the mythical founder of Chinese culture, which holds the key to the identification. Within a week of receiving Bouvet's letter, Leibniz had sent to Abbé Bignon for publication in the Mémoires of the Paris Academy his Explication de l'Arithmétique binaire,... & sue ce qu'elle donne le sens des anciens figures Chinoises de Fohy. Ten days later he sent a brief account to Hans Sloane, the Secretary of the Royal Society. Leibniz viewed binary arithmetic less as a computational tool than as a means of discovering mathematical, philosophical and even theological truths. He remarked to Tschirnhaus in 1682 that he anticipated from the use of binary numbers discoveries in number theory that other progressions could not reveal. It was at the same time a candidate for the characteristica generalis, his long sought-for alphabet of human thought. With base 2 numeration Leibniz witnessed a confluence of several intellectual strands in his world view, including theological and mystical ideas of order, harmony and creation. Fontanelle, secretary of the Paris Academy, wrote the unsigned review of Liebniz's paper for the Mémoires section of the volume. He noted that arithmetic could have different bases besides ten; bases such as 12, and two as in the case of Leibniz's binary system. He also noted that although the binary system was not practical for common use Leibniz thought that it would be of advantage in advanced mathematics" (W.P. Watson, antiquarian book description, http://www.ilabdatabase.com/db/detail.php?booknr=360538539, accessed 01-21-2010).

This manuscript was first published, along with as well as facsimiles of Leibniz's "Explication de l'arithmétique binaire" (1705) and his two letters to Johann Christian Schulenberg on binary arithmetic (March 29 and May 17, 1698), published in the Opera Omnia of 1768, with historical articles and translations in German, to commemorate the 250th anniversary of Leibniz's death as Herrn von Leibniz' Rechnung mit Null und Eins (1966).

Gottfried Wilhlem Leibniz publishes "Brevis descriptio Machinae Arithmeticae, cum Figura" in Miscellanea Berolinensis (1710) 317-19, fig. 73.

This was the first description of Leibniz's stepped-drum calculator, or stepped reckoner. Because Leibniz had only two working examples of the machine made, and one was lost, his invention of the stepped reckoner was primarily known through this and other publications.

Gaspard Riche de Prony completes two manuscript sets of massive logarithmic and trigonometric tables calculated by employing systematic division of mental labor, including the use of mathematically untrained hairdressers unemployed after the French Revolution.

The method of production of the tables inspired Charles Babbage in the design of his Difference Engine No. 1 in 1822.

Portions of de Prony's tables were published for the first time in 1891.

Weaver Michel-Marie Carquillat, working for the firm of Didier, Petit et Cie, in Lyon, France weaves in fine silk a Portrait of Joseph-Marie Jacquard, The image, including caption and Carquillat’s name, taking credit for the weaving, is 55 x 34 cm.; the full piece of silk including blank margins is 85 x 66 cm.

This image, of which only about six examples are known, was woven on the Jacquard loom using 24,000 Jacquard cards, each of which had over 1000 hole positions. The process of mis en carte, or converting the image details to punched cards for the Jacquard mechanism, for this exceptionally large and detailed image, would have taken several workers many months, as the woven image convincingly portrays superfine elements such as a translucent curtain over glass window panes. Once all the “programming” was completed, the process of weaving the image with its 24,000 punched cards would have taken more than eight hours, assuming that the weaver was working at the usual Jacquard loom speed of about forty-eight picks per minute, or about 2800 per hour. More than once this woven image was mistaken for an engraved image. The image was produced only to order, most likely in an exceptionally small number of examples. The only recorded examples are those in the Metropolitan Museum of Art, the Science Museum, London, The Art Institute of Chicago, and the Computer History Museum, Mountain View, California.

The image was the subject of the book by James Essinger entitled, Jacquard’s Web. How a hand loom led to the birth of the information age (2004). To Charles Babbage the incredible sophistication of the information processing involved in the mis en carte -- what we call programming -- of this exceptionally elaborate and beautiful image confirmed the potential of using punched cards for the inputting, programming, and outputting and storage of information in his design and conception of the first general-purpose programmable computer--the Analytical Engine. The highly aesthetic result also confirmed to Babbage that machines were capable of amazingly complex and subtle processes—processes which might eventually emulate the subtlety of the human mind.

“In June 1836 Babbage opted for punched cards to control the machine [the Analytical Engine]. The principle was openly borrowed from the Jacquard loom, which used a string of punched cards to automatically control the pattern of a weave. In the loom, rods were linked to wire hooks, each of which could lift one of the longitudinal threads strung between the frame. The rods were gathered in a rectangular bundle, and the cards were pressed one at a time against the rod ends. If a hole coincided with a rod, the rod passed through the card and no action was taken. If no hole was present then the card pressed back the rod to activate a hook which lifted the associated thread, allowing the shuttle which carried the cross-thread to pass underneath. The cards were strung together with wire, ribbon or tape hinges, and fan-folded into large stacks to form long sequences. The looms were often massive and the loom operator sat inside the frame, sequencing through the cards one at a time by means of a foot pedal or hand lever. The arrangement of holes on the cards determined the pattern of the weave.

“As well as patterned textiles for ordinary use, the technique was used to produce elaborate and complex images as exhibition pieces. One well-known piece was a shaded portrait of Jacquard seated at table with a small model of his loom. The portrait was woven in fine silk by a firm in Lyon using a Jacquard punched-card loom. The image took 24,000 cards to produce, and each card had over 1,000 hole positions. Babbage was much taken with the portrait, which is so fine that it is difficult to tell with the naked eye that it is woven rather than engraved. He hung his own copy of the prized portrait in his drawing room and used it to explain his use of the punched cards in his Engine. The delicate shading, crafted shadows and fine resolution of the Jacquard portrait challenged existing notions that machines were incapable of subtlety. Gradations of shading were surely a matter of artistic taste rather than the province of machinery, and the portrait blurred the clear lines between industrial production and the arts. Just as the completed section of the Difference Engine played its role in reconciling science and religion through Babbage’s theory of miracles, the portrait played its part in inviting acceptance for the products of industry in a culture in which aesthetics was regarded as the rightful domain of manual craft and art” (Swade, The Cogwheel Brain. Charles Babbage and the Quest to Build the First Computer [2000] 107-8).

Mathematician Luigi Federico Menabrea publishes "Notions sur la machine analytique de M. Charles Babbage" in Bibliothèque universelle de Genève, nouvelle série 41 (1842): 352–76.

This was the first published account of Charles Babbage’s Analytical Engine and the first account of its logical design, including the first examples of computer programs ever published. As is well known, Babbage’s conception and design of his Analytical Engine—the first general purpose programmable digital computer—were so far ahead of the imagination of his mathematical and scientific colleagues that few expressed much curiosity regarding it. The only presentation that Babbage made concerning the design and operation of the Analytical Engine was to a group of Italian scientists.

In 1840 Babbage traveled to Torino to make a presentation on the Analytical Engine. Babbage’s talk, complete with charts, drawings, models, and mechanical notations, emphasized the Engine’s signal feature: its ability to guide its own operations—what we call conditional branching. In attendance at Babbage’s lecture was the young Italian mathematician Luigi Federico Menabrea (later prime minister of Italy), who prepared from his notes an account of the principles of the Analytical Engine. Reflecting a lack of urgency regarding radical innovation unimaginable to us today, Menabrea did not get around to publishing his paper until two years after Babbage made his presentation, and when he did so he published it in French in a Swiss journal. Shortly after Menabrea’s paper appeared Babbage was refused government funding for construction of the machine.

"In keeping with the more general nature and immaterial status of the Analytical Engine, Menabrea’s account dealt little with mechanical details. Instead he described the functional organization and mathematical operation of this more flexible and powerful invention. To illustrate its capabilities, he presented several charts or tables of the steps through which the machine would be directed to go in performing calculations and finding numerical solutions to algebraic equations. These steps were the instructions the engine’s operator would punch in coded form on cards to be fed into the machine; hence, the charts constituted the first computer programs [emphasis ours]. Menabrea’s charts were taken from those Babbage brought to Torino to illustrate his talks there"(Stein, Ada: A Life and Legacy, 92).

Menabrea’s 23-page paper was translated into English the following year by Lord Byron’s daughter, Augusta Ada, Countess of Lovelace, who, in collaboration with Babbage, added a series of lengthy notes enlarging on the intended design and operation of Babbage’s machine. Menabrea’s paper and Ada Lovelace’s translation represent the only detailed publications on the Analytical Engine before Babbage’s account in his autobiography (1864). Menabrea himself wrote only two other very brief articles about the Analytical Engine in 1855, primarily concerning his gratification that Countess Lovelace had translated his paper.

Hook & Norman, Origins of Cyberspace (2002) no. 60.

Swedish author, editor, and inventor Georg Scheutz publishes Nytt och enkelt sätt att lösa nummereqvationer af hogre och lägre grader efter Agardhska teorien: För praktiska behov [A new and simple method of solving numerical equations of higher and lower degree with the help of Agardh’s theory: For practical purposes]. and Bihang till skriften: Nytt och enkelt sätt att lösa nummereqvationer af hogre och lägre grader efter Agardhska teorien. Innehällande seriemetodens tillämpning vid bestämmandet af imaginära, lika, och nära hvarandra belägna rötter i en eqvation. Af C[arl] A[dolph] Agardh [1785-1859] . . . Utgifvet af Georg Scheutz [Appendix to the treatise: A new and simple method of solving numerical equations, using Agardh’s theory, containing the serial method used in determining imaginary, exact, and approximate roots of an equation. By C. A. Agardh, . . . edited by G. S.].

The Swedish father-and-son team of Georg and Edvard Scheutz was the first to construct a working difference engine capable of producing printed mathematical tables. The Scheutz machine, of which three examples were built, was based upon Charles Babbage’s design for his famous Difference Engine No. 1, which Babbage worked on intermittently between 1822 and 1834 before abandoning the project uncompleted (only a small working portion, about one-ninth the size of the projected Difference Engine, was ever constructed; the uncompleted machine ended up costing the British Government over £17,000).

Georg Scheutz—described by Lindgren as an “auditor, printer, journalist and editor, political commentator, spokesman for technology, translator and inventor”—first learned of Babbage’s Difference Engine circa 1830. Although his imagination was immediately fired by the possibilities of such a machine, he was unable to begin designing his own version until 1834, when Dionysius Lardner published his detailed review of Babbage’s Difference Engine in the July issue of the Edinburgh Review. Drawing on the information in Lardner’s article, Scheutz and his teenage son Edvard began working on their own design for a difference engine, which was both simpler and cheaper to produce than Babbage’s machine.

The Scheutz difference engine no. 1, a prototype model built by Edvard, was completed in 1843 and certified by members of the Swedish Academy of Sciences. Despite this mark of favor, the Scheutzes were initially unable to stir up any interest or official support for their machine, either at home or abroad. They did no further work on the Scheutz machine until 1850, when, in response to renewed interest in machines for printing tables, they began working on the Scheutz difference engine no. 2.

However, the Scheutz machine no. 1 did not lie entirely fallow during the seven years between 1843 and 1850, for in 1849, Georg Scheutz used it to produce and print a table of a polynomial of the third degree, which he published in Nytt och enkelt sätt att lösa nummereqvationer af hogre och lägre grader efter Agardhska teorien. This little one-column table, found on p. 74 of Scheutz’s pamphlet, is the earliest known automatically produced numerical table.

"In [Scheutz’s Nytt och enkelt sätt att lösa nummereqvationer af hogre och lägre grader efter Agardhska teorien] he gave an exposition of the method of solving equations by the method of differences, which the professor of botany, mathematician and latterly bishop Carl Adolph Agardh had presented in 1809. In an addendum he remarks that while the method is excellent, it is time consuming when used on equations of high degree. He then adds that this disadvantage could be removed if one 'could assign the laborious and time consuming figure work to some assistant, that never tired, never made an error and dealt with the numerical calculations for the higher degrees as swiftly and certainly as those for the first degree.” Georg Scheutz notes that such an assistant does in fact exist and he gives an example of a stereotyped table calculated and printed by the first engine. . . . The table shows that Scheutz still was fascinated by the machine’s capability to solve equations. But more importantly, this table is the only existing illustration [emphasis ours] of what the Scheutz prototype engine could do. It is also the oldest automatically made numerical table in the world, which has been preserved " (Lindgren, Glory and Failure: The Difference Engines of Johann Müller, Charles Babbage and Georg and Edvard Scheutz [1987] 138-39).

Lindgren was the first to note the existence of this numerical table generated by the Scheutz difference engine no. 1. Prior to this, the first examples of tables produced by a Scheutz engine were thought to have been contained in the Scheutz’s Specimens of Tables, Calculated, Stereomoulded and Printed by Machinery (1857), which the Scheutzes produced in both English and French editions as a means of showcasing the Scheutz difference engine no. 2. The standard histories of computing, including Aspray’s Computing before Computers (1990), contain no reference to the table printed by the Scheutz difference engine no. 1. The original publication in Swedish is of the greatest rarity.

Merzbach, Georg Scheutz and the First Printing Calculator (1977). 

The Scheutz team produce their second difference engine—an improvement over the first.

Frank S. Baldwin (United States) and W. T. Odhner (Russia) invent calculators using a true variable-toothed gear, the first real advance in mechanical calculating technology since Gottfried Leibniz's stepped drum (1673). These calculators are called "pinwheel calculators."

The greater ease of use of this technology, its general reliability, and the compact size of the equipment incorporating it caused an explosion of sales in the calculator industry.

Charles Babbage’s son Henry Prevost Babbage completes and publishes his father’s unfinished edition of writings on the Difference Engine No. 1 and the Analytical Engine, together with a listing of his father’s unpublished plans and notebooks. These appear under the title of Babbage’s Calculating Engines.

The "Millionaire" mechanical calculator is introduced in Switzerland.

The "Millionaire" allowed direct multiplication by any digit and was used by government agencies and scientists — especially astronomers — well into the twentieth century.

Philbert Maurice d'Ocagne publishes Le Calcul simplifiée par procèdes mécaniques et graphiques. This contains the first systematic classification of calculating machines.

Percy Ludgate designs a new version of Babbage’s Analytical Engine, of which he publishes a brief description in 1909, and creates engineering drawings.

This would have been the first programmable computer since  Babbage's mid-19th century design. However, the machine was never constructed, and the drawings were lost. (See Reading 6.3.)

The Napier Tercentenary Celebration is held in Edinburgh, though the mathematical meeting scheduled to follow it is canceled because war is considered imminent.

The conference resulted in two scholarly publications on logarithms, mathematical tables, and mechanical calculators. These summarized both historical and current information for the period up to World War I. (See Readings 3.2 and 6.3.)

Vannevar Bush of MIT develops the differential analyzer, a large analog computer more accurate than previous devices of this type.

Konrad Zuse applies for a patent on his electromagnetic, program-controlled calculator, called the Z1. 

Zuse built the machine in the living room of his parents’ apartment in Berlin. It had 30,000 parts.

The Z1 was the first freely programmable, binary-based calculating machine ever built, but it did not function reliably, and it was destroyed in World War II. Zuse's patent application is the only surviving documentation of Zuse's prewar work on computers.

Between 1986 and 1989 Zuse and three associates created a replica of the Z1, which is preserved in the Deutsche Technikmuseum.

Believing that war with Germany is inevitable, Alan Turing builds in a Princeton University machine shop an experimental electromechanical cryptanalysis machine capable of binary multiplication.

George Stibitz, a research mathematician at Bell Telephone Labs in New York City, builds a binary adder out of a few light bulbs, batteries, relays and metal strips cut from tin cans on his kitchen table.

This device was similar to a theoretical design described by Claude Shannon in his master's thesis. Stibitz's "Model K" (for “Kitchen”) was the first electromechanical computer built in America.

Howard Aiken drafts a proposal for an automatic calculating machine and joins with IBM to produce the Automatic Sequence Controllec Calculator (ASCC). Later known as the Harvard Mark I, the completed electromechanical calculating machine will eventually weigh five tons.

John Atanasoff at Iowa State University, Ames, Iowa, plans the Atanasoff-Berry Computer (ABC), a special-purpose electronic computer.

John Atanasoff begins work on his special-purpose ABC machine, the earliest electronic digital computer. It will never be properly operational.

Konrad Zuse completes his Z2 machine. It uses the same kind of mechanical memory as the Z1 but uses 800 relays in the arithmetic and control units. .

George Stibitz and Samuel Williams of Bell Telephone Labs begin construction of the Complex Number Calculator (later known as the Bell Labs Model I).

This machine was called “the first electromechanical computer for routine use.” It used telephone relays and coded decimal numbers as groups of four binary digits (bits) each.

Konrad Zuse’s associate, Helmut Schreyer, writes a memorandum concerning the Z2, Rechnische Rechenmachine (unpublished at the time), in which he also says it would be possible to build a computer with vacuum tubes that would process “10,000 operations per second.”

The Bell Labs Complex Number Calculator is operational.

John Atanasoff writes a thirty-five-page memorandum describing the design and principles of the ABC machine.

This may be the earliest extant document describing the principles of an electronic digital computer. It remained unpublished until 1973.

John Mauchly meets John Atanasoff at the Philadelphia meeting of the American Association of the Advancement of Science.

After corresponding with Atanasoff about electronic calculating, Mauchly visited Atanasoff in Iowa and read the 35-page memorandum on the ABC machine that Atanasoff had written in August.

Alan Turing and Gordon Welchman at Bletchley Park design an improved Bombe cryptanalysis machine for deciphering Enigma messages.

Helmut Schreyer, Konrad Zuse’s associate, receives his doctorate in telecommunications engineering with a dissertation on the use of vacuum-tube relays in switching circuits.

Schreyer converted Zuse’s logical designs into electronic circuits, building a simple prototype of an electronic computer, which achieved a switching frequency of 10,000 Hz.

Konrad Zuse completes his Z3 machine—the world’s first fully functional Turing-complete electromechanical digital computer--with twenty-four hundred relays.

The Z3 ran programs punched into rolls of discarded movie film. In 1944 it was destroyed in bombing raids.

Because no one outside of Germany had any knowledge of the Z3, Zuse's design had no influence on the development of computing in the the United States or England during or after World War II.

J. Presper Eckert and John Mauchly meet at the Moore School of Electrical Engineering, University of Pennsylvania, and begin discussions on electronic computing.

John Atanasoff’s special-purpose ABC machine is nearly operational when work on it is abandoned because of World War II.

Konrad Zuse starts work on the Z4 electromechanical computer.

Vannevar Bush completes the Rockefeller Differential Analyzer II, a monstrous machine more accurate and faster than the first Differential Analyzer. It contained two thousand vacuum tubes and weighed about one hundred thousand pounds. For security reasons its existence was not publicized until October 1945.

John Mauchly writes a privately circulated confidential memorandum on “The Use of High Speed Vacuum Tube Devices for Calculating”

IBM develops the Vacuum Tube Multiplier.

This experimental machine was the first complete machine to perform arithmetic electronically. By substituting vacuum tubes for electro-mechanical relays it could process information thousands of times faster than electro-mechanical calculators.

Project Whirlwind starts as an analog flight simulator project at MIT.

Mathematical Tables and Other Aids to Computation (MTAC), the world’s first computing journal, begins publication.

At this time mathematical tables prepared by human computers were the primary calculating aid. The journal reported on the new electromechanical and electronic “aids to computation” as they were developed.

Howard Aiken’s electromechanical Harvard Mark I operates at IBM Endicott Labs in New York under wartime security.

This was one of the first two programmed computers built by Americans.

With the goal of speeding up the calculation of artillery firing tables, Pres Eckert and John Mauchly of the Moore School of Electric Engineering submit a proposal to the Ballistic Research Laboratory at Aberdeen Proving Ground.

It was entitled Report on an Electronic Difference Analyzer. The name tried to make the distinction between the electromechanical analog differential analyzer that the United States Army was using and the new electronic digital machine that would be developed. The proposal was submitted to army ordnance in May.

When the first contracts were signed between the United States Army and the Moore School, the name of the machine was changed to Electronic Numerical Integrator. Because Mauchly stressed that the machine could be used for more general problems, the device was called an “Electronic Numerical Integrator and Computer (ENIAC).” Eckert was appointed laboratory supervisor and chief engineer on the project. Mauchly, along with Eckert, was put in charge of engineering and testing.

Pres Eckert submits a report entitled Disclosure of Magnetic Calculating Machine, which briefly describes means for storing data on magnetic disks and also the storing of programs on disks. It does not enunciate the principles of the stored-program computer.

Pres Eckert has two accumulators of the ENIAC operational.

Faced with mathematical computations regarding the Atomic bomb that are too time-consuming for human computers, John von Neumann visits the ENIAC two-accumulator system for the first time, and becomes deeply interested in the project.

Pres Eckert and John Mauchly state that their conception of the ENIAC is complete.

Eckert wrote a letter to other members of the project asking them to state written claims to inventions on the project. None was received.

The United States Army extends the ENIAC contract to cover research on the planned EDVAC stored-program computer.

Konrad Zuse completes the Z4 shortly before V-E Day. 

The Z4 was a large, electromechanical programmable machine, the construction of which began about 1943. To safeguard it against bombing, the machine was dismantled and shipped from Berlin to a village in the Bavarian Alps. In 1950 it was refurbished, modified, and installed at ETH in Zurich. For several years it was the only working electronic digital computer in continental Europe, and it remained operational in Zurich until 1955. It is preserved in the Deutsches Museum in Munich.

Mathematician and physicist John von Neumann  privately circulates copies of his First Draft on a Report on the EDVAC to twenty-four people connected with the EDVAC project.

This document, written between February and June 1945, provided the first theoretical description of the basic details of a stored-program computer what later became known as the Von Neumann architecture.

To avoid the government's security classification, and to avoid engineering problems that might detract from the logical considerations under discussion, Von Neumann avoided mentioning specific hardware. Influenced by Alan Turing and by Warren McCulloch and Walter Pitts, von Neumann patterned the machine to some degree after human thought processes. (See Reading 8.1.)

In June 2009 I was able to download a PDF of the text of von Neumann's report at this link: http://www.virtualtravelog.net/entries/2003-08-TheFirstDraft.pdf.

Alan Turing arrives at the National Physical Laboratory,Teddington, England, to work on the Automatic Computing Engine (ACE).

Project Whirlwind switches from analog to digital electronics.

Pres Eckert, John Mauchly, John Brainerd, and Herman Goldstine issue the first confidential published report on the completed ENIAC, discussing how it operates and the methods by which it is programmed. (See Reading 8.2.)

The Moore School lectures on “The theory and techniques for design of electronic digital computers” take place. This series of lectures, attended by twenty-eight highly qualified experts, led to widespread adoption of the EDVAC-type design, including stored programs, for nearly all subsequent computer development.

Howard Aiken and Grace Hopper publish A Manual of Operation for the Automatic Sequence Controlled Calculator. The instruction sequences scattered throughout this volume are among the earliest published examples of digital computer programs. (See Reading 9.1.)

Alan Turing prepares a typed proposal, “Proposed electronic calculator,” outlining the development of the ACE.

In June 2009 I was able to download a PDF of Turing's report at this link: http://www.emula3.com/docs/Turing_Report_on_ACE.pdf

John von Neumann attempts to set up an electronic stored-program computer project at the Institute for Advanced Study (IAS) at Princeton.

Von Neumann tried to hire Pres Eckert, but Eckert refused the job, preferring to go into the computer business with John Mauchly.

Julian Bigelow, who previously collaborated with Norbert Wiener at MIT, joins John von Neumann and Herman Goldstine at the Princeton IAS Electronic Computer Project. He was to a large extent responsible for implementing von Neumann's stored-program concepts.

Arthur W. Burks, John von Neumann, and Herman Goldstine issue their Preliminary Discussion of the Logical Design of an Electronic Computing Instrument, discussing ideas to be incorporated into the stored-program computer at the IAS. (See Reading 8.3.)

Pres Eckert lectures at University of Pennsylvania's Moore School on “A preview of a digital computing machine.” He proposes replacing  the three different kinds of memory used in the ENIAC (flip-flops in accumulators, function tables [read-only memory] and interconnecting cables with switches) with a single erasable high-speed memory --  the mercury delay-line memory that he invented for this purpose. The was a key step in the development of a stored-program computer.

The ENIAC is converted into an elementary stored-program computer via the use of function tables.

EDVAC information is declassified

Louis Couffignal and Leon Brillouin hold a small conference on “large computers” in Paris, at which Couffignal discusses French work, and Brillouin summarizes American accomplishments in electronic digital computing.

Couffignal decided against building a stored-program computer. This mistake caused France to fall behind England and America in this technology. The first stored-program computer wasnot manufactured in France until 1956. The government agency where Couffignal worked, Centre National de la Recherche Scientifique (CNRS), did not obtain a stored-program computer (a British model) until 1955.

Design of the Whirlwind I begins at MIT.

The Curta Model 1 pocket mechanical calculator is produced by Contina Ltd in Vaduz, Liechtenstein.

The most advanced small mechanical calculator ever built, the Curta was designed by Curt Hertzstark, a calculating machine manufacturer, while he was a prisoner in Buchenwald concentration camp from 1943 to 1945. The Nazis operating the concentration camp encouraged Hertzstark to complete the design while he was in Buchenwald, and produced a prototype by the end of the war. The Curta calculator was manufactured until 1973.

In a lecture to the London Mathematical Society that remained unpublished until 1986, Alan Turing stated that “digital computing machines such as the ACE. . . are in fact practical versions of the universal machine.”

Pres Eckert and John Mauchly learn from a patent lawyer that John von Neumann’s First Draft of a Report on the EDVAC is a publication barring their patenting the ENIAC because it was issued more than a year before they planned to apply for a patent.

Julian Bigelow and his team redesign the IAS machine to include error checking and parallel processing, essential features of what will become known as the von Neumann architecture.

Pres Eckert and John Mauchly apply for the broad ENIAC patent, essentially a patent on the stored-program electronic digital computer, basing their description of the machine to a large extent on the government report they issued on November 30, 1945. (See Reading 8.10.)

Northrop Aviation places the contract for the BINAC (BINary Automatic Computer) with Pres Eckert and John Mauchly’s Electronic Control Company. The BINAC consisted of two identical serial computers operating in parallel with mercury delay-line memory, and magnetic tape as a secondary memory and auxiliary input device.

Pres Eckert and John Mauchly apply for a U.S. patent on the mercury acoustic delay-line electronic memory system. This was the "first device to gain widespread acceptance as a reliable computer memory system." (Hook & Norman, Origins of Cyberspace [2002] 1191). The patent 2,629,827 was granted in 1953.

IBM produces the 604 Card-Programmed Electronic Calculator (CPC). Based on vacuum-tube technology, and programmed by making wired connections on a plugboard, the mass-produced CPC 604 featured the industry’s first assemblage of digital electronics replaceable as a unit.

Andrew D. Booth creates a magnetic drum memory, two inches long and two inches wide and capable of holding 10 bits per inch.

Booth offered his magnetic memory units for sale in 1952.

IBM announces its first large-scale digital calculating machine, the Selective Sequence Electronic Calculator (SSEC).

The SSEC was the first computer that could modify a stored program. It featured 12,000 vacuum tubes and 21,000 electromechanical relays.

“IBM's Selective Sequence Electronic Calculator (SSEC), built at IBM's Endicott facility under the direction of Columbia Professor Wallace Eckert and his Watson Scientific Computing Laboratory staff in 1946-47, . . . was moved to the new IBM Headquarters Building at 590 Madison Avenue in Manhattan, where it occupied the periphery of a room 60 feet long and 30 feet wide. . . . [Estimates of the] dimensions of its "U" shape [were] at 60 + 40 + 80 feet, 180 feet in all, (about half a football field!)”

 "Designed, built, and placed in operation in only two years, the SSEC contained 21,400 relays and 12,500 vacuum tubes. It could operate indefinitely under control of its modifiable program. On the average, it performed 14-by-14 decimal multiplication in one-fiftieth of a second, division in one-thirtieth of a second, and addition or subtraction on nineteen-digit numbers in one-thirty-five-hundredth of second... For more than four years, the SSEC fulfilled the wish Watson had expressed at its dedication: that it would serve humanity by solving important problems of science. It enabled Wallace Eckert to publish a lunar ephemeris ... of greater accuracy than previously available... the source of data used in man's first landing on the moon". "For each position of the moon, the operations required for calculating and checking results totaled 11,000 additions and subtractions, 9,000 multiplications, and 2,000 table look-ups. Each equation to be solved required the evaluation of about 1,600 terms — altogether an impressive amount of arithmetic which the SSEC could polish off in seven minutes for the benefit of the spectators" (http://www.columbia.edu/acis/history/ssec.html#sources, accessed 03-24-2010).

The SSEC remained sufficiently influential in the popular view of mainframes that it was the subject of a cartoon by Charles Addams published on the cover of The New Yorker magazine in February 11, 1961, in which the massive machine produced a Valentine's Day card for its elderly woman operator!

The Manchester Small Scale Experimental Machine or  Manchester "Baby" prototype computer, runs its first program, written by Tom Kilburn.

This small pilot version of a larger computer was built at the University of Manchester in England to demonstrate the Williams-Kilburn cathode ray tube (CRT) memory. The Manchester “Baby” was the first stored-program electronic digital computer. It operated for only a short time.

You can watch a streaming video of a 1948 BBC newsreel about the Manchester "Baby" at this link. [You will need to scroll down the web page.]

Alan Turing writes a report for the National Physical Laboratory entitled Intelligent Machinery.

In the report Turing stated that a thinking machine should be given the blank mind of an infant instead of an adult mind filled with opinions and ideas. The report contained an early discussion of neural networks. Turing estimated that it would take a battery of programmers fifty years to bring this learning machine from childhood to adult mental maturity. The report was not published until 1968.

The second module of the BINAC (the first was completed in August), is completed. Among its numerous innovations were germanium diodes in the logic processing hardware—probably the first application of semiconductors in computers. Until its delivery to Northrop Aviation in September 1949, the BINAC remained in Philadelphia for use in numerous sales demonstrations.

Edmund Berkeley publishes Giant Brains or Machines that Think, the first popular book on electronic computers.

Among many interesting details, Giant Brains contains a discussion about a machine called Simon, which has been called the first personal computer. (See Reading 8.6.)

Betty Holbertson at Eckert-Mauchly develops UNIVAC Instructions Code C-10.

C-10 was the first software to allow a computer to be operated by keyboarded commands rather than dials and switches. It was also the first mnemonic code.

Under the name Project Charles, the Air Force funds a project proposed by George Valley and Jay Forrester of MIT to develop a military grade version of the Whirlwind computer in order to develop an automated detection and interception system to protect the entire U.S. from incoming bombers. This  evolved into the Semi-Automatic Ground Environment or SAGE system.

Albert A. Auerbach, one of the designers of the BINAC CPU at Pres Eckert and John Mauchly's Electronic Control Company, runs a small test routine for filling memory from the A register. This was the first program run on the first stored-program electronic computer produced in the United States.

Maurice V. Wilkes’s EDSAC, fully operational at Cambridge, England, runs a program written by Wilkes for calculating a table of squares. It also ran a program written by David Wheeler for calculating a sequence of prime numbers. The EDSAC was the first easily used, fully functional stored-program computer to run a program.

The first test program is run on Trevor Pearcey's and Maston Beard’s CSIR Mk1, the first stored-program computer in Australia. The machine was renamed CSIRAC in 1956.

Excluding the BINAC, which only operated for a short time, the CSIR Mk1 was one of only three stored-program computers operating in the world at this time.

Three-dimensional magnetic-core memory replaces electrostatic memory on the Whirlwind I, leading to increased performance and reliability.

The Paris symposium,  Les Machines á calculer et la pensée humaine (Calculating Machines and Human Thought) takes place at l'Institut Blaise Pascal.

Unlike the other early computer conferences, no demonstration of a stored-program electronic computer took place.  Louis Couffignal demonstrated the prototype of his non-stored-program machine.

Hook & Norman, Origins of Cyberspace (2002) no. 526.

Whirlwind I begins operation.

Whirlwind I included the first primitive graphical display on its vectorscope screen. (See Reading 8.7.)

The second English electronic computer conference is held at Manchester to inaugurate the first Ferranti Mark I.

There Maurice Wilkes introduced the term microprogramming, referring to the design of control circuits. The idea was not widely accepted until the following decade. (See Reading 8.8.)

The EDVAC, planning for which had started in 1944, with development starting in 1947-48, is finally operational at the Moore School in Philadelphia. By this time it was essentially obsolete.

Manufacturers begin producing vacuum tubes especially designed for use in digital circuits.

Three-dimensional magnetic-core memory replaces electrostatic memory on the Whirlwind I, leading to increased performance and reliability.

British electrical engineer Kenyon Taylor and team, working on the Royal Canadian Navy's DATAR project, invent the first trackball, a precursor of the computer mouse. It uses a standard Canadian five-pin bowling ball.

Sergei Lebedev has MESM, the first Russian stored-program computer, operational.

The IAS computer is fully operational at Princeton.

Heinz Billing's G1 is in full operation at the Max Planck Institute in Göttingen, directed by Werner Heisenberg.

This was the first electronic computer in Germany. It used drum memory, but it was not a stored-program machine.

IBM introduces the 701, their first stored-program electronic computer for commercial production.

Designed by Nathaniel Rochester, and based on the IAS machine at Princeton, the IBM 701 was intended for scientific use. Feeling that the word "computer" was too closely associated with UNIVAC, IBM called the 701 an “electronic data processing machine.” IBM eventually sold nineteen of these machines. (See Reading 8.9.)

"The 701 has at least 25 times the over-all speed but is less than one-quarter the size of IBM's Selective Sequence Electronic Calculator, which was dismantled to make room for its speedier successor."

"During its five-year reign as one of the world's best-known "electronic brains," the SSEC solved a wide variety of scientific and engineering problems, some involving many millions of sequential calculations. Such other projects as computing the positions of the moon for several hundred years and plotting the courses of the five outer planets -- with resulting corrections in astronomical tables which had been considered standard for many years -- won such popular acclaim for the SSEC that it stimulated the imaginations of pseudo-scientific fiction writers and served as an authentic setting for such motion pictures as "Walk East on Beacon," a spy-thriller with an FBI background.

"Though the 701 occupies the same quarters as the SSEC, which it rendered obsolete, it is not "built in" to the room as was its predecessor. Instead, it is smartly housed between serrated walls of soft-finished aluminum. A balconied conference room, overlooking the calculator and, separated from it by sloping plate glass, provides a vantage point for observing operations and discussing computations. Ample space is provided for writing the complex and abstract equations that are the stock in trade of engineers and scientists in an age of atomic energy and supersonic flight.

"The 701 uses all three of the most advanced electronic storage, or "memory" devices -- cathode ray tubes, magnetic drums and magnetic tapes. The computing unit uses small versions of the familiar electronic tubes, which are able to count at millions of pulses a second. In addition, several thousand germanium diodes are used in place of vacuum tubes, with resultant savings in space and power requirements.

"The 701 was designed for scientific and research purposes, and similar components are adaptable to the requirements of accounting and record-keeping. Research on commercial, data processing machines is under way.

"The 701 is capable of performing more than 16,000 addition or subtraction operations a second, and more than 2,000 multiplication or division operations a second. In solving a typical problem, the 701 performs an average of 14,000 mathematical operations a second."

(quotations from IBM's original press release from the IBM Archives website).

English Electric constructs a commercial version of Alan Turing’s Pilot ACE called DEUCE.

Thirty-three of the DEUCE machines were sold, the last in 1962.

IBM develops and builds the Naval Ordnance Research Computer (NORC)—for the U.S. Navy Bureau of Ordnance.

The NORC was the "first supercomputer," and "the most powerful computer on earth from 1954 to about 1963." The NORC’s multiplication unit remains the fastest ever built with vacuum tube technology.

IBM introduced the input-output channel as a feature on the NORC. This innovation synchronized the flow of data into and out of the computer while computation was in progress, relieving the central processor of that task.

Development begins on the SAGE Air Defense System, using a computer built by IBM after a design based on the Whirlwind. It includes the first light pen.

The full SAGE system was completed by 1963.

IBM introduces the IBM 608 transistor calculator, the first all solid-state computer commercially marketed.

IBM develops magnetic core storage units, a dramatic improvement over cathode ray tube memory technology.

By successfully adapting pill-making machines for production, IBM greatly improved the manufacture of these tiny, “doughnut” shaped, iron oxide cores, making the cores reliable and cost effective enough to serve as the basic technology behind every computer’s main memory until the early 1970s.

The ENIAC is turned off for the last time.

It was estimated that this single machine did more computation during the ten years of its operation than the entire human race had done up till the time of its invention.

ETL-Mark-2, the first full-scale programmable computer in Japan, is produced by the Electrotechnical Laboratory in Japan. It is built from twenty-one thousand relays and does not store a program.

FUJIC, the first Japanese stored-program electronic computer, is designed and built by essentially one person--Dr. Okazaki Bunji--for the Fuji Photo Film Company. The project began in 1949.

"Originally designed to perform calculations for lens design by Fuji, the ultimate goal of FUJIC's construction was to achieve a speed 1,000 times that of human calculation for the same purpose – amazingly, the actual performance achieved was double that number.

"Employing approximately 1,700 vacuum tubes, the computer's word length was 33 bits. It had an ultrasonic mercury delay line memory of 255 words, with an average access time of 500 microseconds. An addition or subtraction was clocked at 100 microseconds, multiplication at 1,600 microseconds, and division at 2,100 microseconds."

The Burroughs “Atlas Guidance” computer is used to control the launch of the Atlas missile. It is one of the first computers to use transistors.

IBM phases out vacuum tubes in computer design: “It shall be the policy of IBM to use solid-state circuitry in all machine developments. Furthermore, no new commercial machines or devices shall be announced which make primary use of tube circuitry.”

EDSAC 2, the first large-scale computer with a control unit based on microprogramming, becomes operational in Cambridge, England.

The first SAGE AN/FSQ7 is operational for the SAGE Air Defense System on a limited basis.

The system allowed online access, in graphical form, to data transmitted to and processed by its computers. Fully deployed by 1963, the IBM-built early warning system remained operational until 1984. With 23 direction centers situated on the northern, eastern, and western boundaries of the United States, SAGE pioneered the use of computer control over large, geographically distributed systems.

Commercial transistorized computers, including the UNIVAC Solid State 80 and the Philco TRANSAC S-2000, are introduced. These inaugurate the so-called second generation of electronic computers.

Lejaren Hiller and Leonard Isaacson collaborate on the first significant computer music composition, the Illiac Suite. 

The Illiac Suite was composed on the University of Illinois ILLIAC I computer, the first von Neumann architecture computer built and owned by an American university.

Konrad Zuse produces the Z22, the first commercial electronic digital computer in Germany.

It used vacuum tubes at this relatively late date for that technology. Zuse KG was the first independent German electronic computer company. It was eventually purchased by Siemens.

Seymour Cray of Control Data Corporation builds the first transistorized supercomputer, the CDC 1604.

IBM announces their 1401, a relatively inexpensive computer that proves very popular with businesses, and which begins to compete seriously with existing punched-card equipment.

IBM begins production of the the AN/FSQ-7, a military grade version of the Whirlwind.

"The AN/FSQ-7 used 55,000 vaccuum tubes, about 1/2 acre(2,000 m²) of floor space, weighed 275 tons and used up to three megawatts of power. Although the failure rate of an individual tube was low due to efforts in quality control. So many were used that the daily failure rate was in the hundreds. Each center had staff dedicated to replacing dead tubes by running up and down the racks of machinery with shopping carts filled with replacements. The AN/FSQ-7s remain the largest computers ever built, and will likely hold that record in the future. Each SAGE site included two computers for redundancy, with one processor on "hot standby" at all times. In spite of the poor reliability of the tubes, this dual-processor design made for remarkably high overall system uptime. 99% availability was not unusual."

Wesley A. Clark designs and builds the TX-2 computer at MIT’s Lincoln Laboratories. It had 320 kilobytes of fast memory, about twice the capacity of the biggest commercial machines. Other features were magnetic tape storage, an on-line typewriter, the first Xerox printer, paper tape for program input, and a nine inch CRT screen. Among its applications were development of interactive graphics and research on human-computer interaction.

The Advanced Research Projects Agency (ARPA) of the United States Defense Department increases funding for research on computing.

IBM introduces a transistorized version of its vacuum-tube-logic 709 computer, the 7090.

The 7090 was the first commercially available general purpose computer with transistor logic. It became the most popular large computer of the early 1960s.

Mathematician and founder of Stanford University's Computer Science department, George E. Forsythe coins the term "computer science" in his paper "Engineering Students Must Learn both Computing and Mathematics", J. Eng. Educ. 52 (1961) 177-188, quotation from p. 177:

"In 1961 we find him using the term 'computer science' for the first time in his writing:

[Computers] are developing so rapidly that even computer scientists cannot keep up with them. It must be bewildering to most mathematicians and engineers...In spite of the diversity of the applications, the methods of attacking the difficult problems with computers show a great unity, and the name of Computer Sciences is being attached to the discipline as it emerges. It must be understood, however, that this is still a young field whose structure is still nebulous. The student will find a great many more problems than answers. 

"He identified the "computer sciences" as the theory of programming, numerical analysis, data processing, and the design of computer systems, and observed that the latter three were better understood than the theory of programming, and more available in courses" (Knuth, "George Forsythe and the Development of Computer Science," Communications of the ACM, 15 (1972) 722).

Wesley A. Clark, a computer scientist at MIT, starts building the Linc (Laboratory instrument computer).

The machine, which some later called both the first mini-computer and a forerunner of  the personal computer, was first used in 1962. It had small table-top size, “low cost” ($43,000), keyboard and display, file system and an interactive operating system. It's design was placed in the public domain. Eventually fifty of the machines were sold by Digital Equipment Corporation.

John W. Haanstra, Chairman, Bob O. Evans, Vice Chairman and others at IBM issue as a confidential internal document Processor Products—Final Report of SPREAD Task Group.

In the period from 1952 through 1962, IBM produced seven families of systems—the 140, 1620, 7030 (Stretch), 7040, 7070, 7080, and 7090 groups. They were incompatible with one another, and both users and IBM staff recognized problems caused by this incompatibility. The SPREAD report, as adopted by IBM, led to the development of the IBM System/360 family of compatible computers and peripherals, and essentially reformed the company.

"IBM's public commitment to the SPREAD plan was embodied in the System/360, announced in Poughkeepsie on April 7, 1964. Six machines were announced: the 360 Model 30, 40, 50, 60, 62 and 70. Over the next few years, a number of additional systems were added to the 360 family.

"The SPREAD plan eventually allowed IBM to direct substantial resources toward the development of the full system—peripherals, programming, communications, and new applications. The success of System/360 is perhaps best measured by IBM's financial performance. In the six years from January 1, 1966 to December 31, 1971, IBM's gross income increased 2.3 times, from $3.6 billion to $8.3 billion, and net earnings after taxes increrased 2.3 times, from $477 million to $1.1 billion. In 1982 direct descendants of System/360 accounted for more than half of IBM's gross income and earnings.

"Perhaps most important, the SPREAD Report permitted IBM to focus on an excellence not possible with multiple architectures. It resulted in powerful new peripherals, programming, terminals, high-volume applications, and complementary diversifications whose future can only be imagined" (Bob O. Evans, "Introduction to SPREAD Report," Annals of the History of Computing 5 [1983] 5).  The text of the report was reprinted in the same journal issue on pp. 6-26.

Nearly all copies of this confidential report were destroyed. An original copy, donated by one of the authors, Jerome Svigals, is preserved in the Computer History Museum.

Digital Equipment Corporation introduces the PDP-5, DEC’s first 12 bit computer.

This was later called “the world’s first commercially produced mini computer.” The PDP-8 introduced in 1965 was also given this designation.

RCA announces the Spectra series of computers, which can run the same software as IBM’s 360 machines. The Spectra computers were the first commercial computers to use integrated circuits.

Pres Eckert and John Mauchly receive patent no. 3,120,606 for the ENIAC, a general patent on the stored-program electronic computer. Sperry Rand Univac, owner of the patent, charged a 1.5 percent royalty for all electronic computers sold by all companies except IBM, with which it had previously cross-licensed patents.

IBM announces the System/360 family of compatible machines.  All IBM System/360 products ran the same operating system—OS/360. Previously products developed by different divisions of IBM were incompatible.

IBM System/360 products were the first IBM computers capable of both commercial and scientific applications that were offered at what was considered a “reasonable price.” Their architecture incorporated Microprogramming.

M. R. Davis and T. O. Ellis of The Rand Corporation publish The RAND Tablet: A Machine Graphical Communication Device. They indicate that the device had been in use since 1963.

"The RAND table is believed to be the first such graphic device that is digital, is relatively low-cost, possesses excellent linearity, and is able to uniquely describe 10 [to the 6th power] locations in the 10" x 10" active table area. . . . the tablet has great potential no only in such applications as digitizing map information, but also as a working tool in the study of more esoteric applications of graphical languages for man-machine interaction. . . . " (p.iv)

"The RAND tablet device generates 10-bit x and 10-bit y stylus position information. It is connected to an input channel of a general-purpose computer and also to an oscilloscope display. The display control multiplexes the stylus position information with computer-generated information in such a way that the oscilloscope display contains a composite of the current pen position (represented as a dot) and the computer output. In addition, the computer may regenerate meaningful track history on the CRT, so that while the user is writing, it appears that the pen has "ink." This displayed "ink" is visualized from the oscilloscope display while hand-directing the stylus position on the tablet. users normally adjust within a few minutes to the conceptual superposition of the displayed ink and the actual off-screen pen movement. There is no apparent loss of ease or speed in writing, printing, constructing arbitrary figures, or even in penning one's signature" (pp. 2-3).

J. W. Ward, History of Pen Computing: Annotated Bibliography in On-line Character Recognition and Pen Computing: http://rwservices.no-ip.info:81/pens/biblio70.html#DavisMR64 , accessed 12-30-2009).

DEC introduces the PDP-8, the first “production model minicomputer.” “Small in physical size, selling in minimum configuration for under $20,000.”

Honeywell attempts to open the home computer market with its Kitchen Computer.

The H316 was the first under-$10,000 16-bit machine from a major computer manufacturer. It was the smallest addition to the Honeywell "Series 16" line, and was available in three versions: table-top, rack-mountable, and self-standing pedestal. The pedestal version, complete with cutting board, was marketed by Neimann Marcus as "The Kitchen Computer.” It came with some built-in recipes, two weeks' worth of programming, a cook book, and an apron.

There is no evidence that any examples were sold.

Texas Instruments files the patent for the first hand-held electronic calculator, invented by Jack S. Kilby, Jerry Merryman, and Jim Van Tassel. The patent (Number 3,819,921) was awarded on June 25, 1974.

This miniature calculator employed a large-scale integrated semiconductor array containing the equivalent of thousands of discrete semiconductor devices.

Douglas Engelbart of the Stanford Research Institute demonstrates at the San Francisco Convention Center an “oNLine System” (NLS), the features of which include hypertext, text editing, screen windowing, and email. To make this system operate, Engelbart uses the mouse which he had invented the previous year.

DEC (Digital Equipment Corporation) introduces the PDP-11 minicomputer, which popularizes the notion of a “bus” (i.e.“Unibus”) onto which a variety of additional circuit boards or peripheral products can be placed.

DEC sold 20,000 PDP-11s by 1975.

Xerox opens the Palo Alto Research Center (PARC).

PARC became the incubator of the Graphical User Interface (GUI), the mouse, the WYSIWYG text editor, the laser printer, the desktop computer, the Smalltalk programming language and integrated development environment, Interpress (a resolution-independent graphical page description language and the precursor to PostScript), and Ethernet.

Gilbert Hyatt files a patent application entitled Single Chip Integrated Circuit Computer Architecture based on work begun in 1968.

Hyatt's patent was the first general patent on the microprocessor. Twenty years later, in 1990, the U.S. Patent Office awarded the patent, but was overturned in 1995.

Intel announces the first microprocessor: the 4004 four-bit central processor logic chip designed by Federico Faggin. 

C. Gordon Bell and Allen Newell publish Computer Structures: Readings and Examples, a systematized presentation of the principles governing the design of computer systems.

The Alto computer system is operational at Xerox PARC.

Conceptually the first personal computer system, the Alto eventually featured the first WYSYWG (What You See is What You Get) editor, a graphic user interface (GUI), networking through Ethernet, and a mouse. When offered for sale the system was priced $32,000.

IBM builds the first prototype computer employing RISC (Reduced Instruction Set Computer) architecture.

Based on an invention by John Cocke, the RISC concept simplified the instructions given to run computers, making them faster and more powerful. It was implemented in the experimental IBM 801 minicomputer. The goal of the 801 was to execute one instruction per cycle.

In 1987 John Cocke received the A. M. Turing Award for significant contributions in the design and theory of compilers, the architecture of large systems and the development of reduced instruction set computers (RISC); for discovering and systematizing many fundamental transformations now used in optimizing compilers including reduction of operator strength, elimination of common subexpressions, register allocation, constant propagation, and dead code elimination.

Gerald J. Popek and Robert P. Goldberg publish Formal Requirements for Virtualizable Third Generation Architectures, a set of conditions sufficient to support system virtualization efficiently in computer architecure. 

"Even though the requirements are derived under simplifying assumptions, they still represent a convenient way of determining whether a computer architecture supports efficient virtualization and provide guidelines for the design of virtualized computer architectures."

Intel announces the 8080 eight-bit microprocessor.

The 8080 powered the MITS Altair 8800 designed by H. Edward Roberts, the first truly inexpensive personal computer. Within a year the 8800 was designed into hundreds of different products.

H. Edward Roberts, working in Albuquerque, New Mexico, announces the MITS (Micro Instrumentation Telemetry Systems) Altair personal computer kit in an article in Popular Electronics magazine.

The first personal computer to be offered for sale, the MITS Altair had an “open architecture.”

The basic Altair 8800 sold for $397.

Apple introduces the Apple II, the first personal computer sold as a fully assembled product, and the first with color graphics.

Wang introduces its VS minicomputer system, which becomes one of the most popular office systems, "inaugurating the concept of office automation."

Intel introduces the 8086 microprocessor, which would give rise to the x86 architecture.

Intel introduces the 8088 microprocessor, a low-cost version of the 8086 using an eight-bit external bus.

Xerox introduces the 8010 Star Information System, the first commercial system to incorporate a bitmapped display, a windows-based graphical user interface, icons, folders, mouse, Ethernet networking, file servers, printer servers and e-mail.

Osborne produces the first commercially successful portable computer, the Osborne 1. It weighs twenty-three pounds, runs the CP/M operating system, and sells for $1795, with $2000 worth of software included.

IBM introduces their open architecture personal computer (PC) based on the Intel 8088 processor.

The IBM PC ran PC-DOS, the IBM-branded version of the 16-bit operating system, MS-DOS, provided by Microsoft. The IBM PC was originally designated as the IBM 5150, putting it in the "5100" series, though its architecture was not directly descended from the IBM 5100.

On August 1, 1981 a review of the IBM PC appeared on USENET (accessed 10-16-2009).

SUN Microsystems, founded in February of this year by students at Stanford who worked on the Stanford University Network, announces its first UNIX workstation, the Sun 1.

"The initial design for what became Sun's first Unix workstation,  was conceived by Andy Bechtolsheim when he was a graduate student at Stanford University in Palo Alto, California. He originally designed the SUN workstation for the Stanford University Network communications project as a personal CAD workstation. It was designed as a 3M computer: 1 MIPS, 1 Megabyte and 1 Megapixel. It was designed around the Motorola 68000 processor with an advanced Memory management unit (MMU) to support the Unix operating system with virtual memory support. He built the first ones from spare parts obtained from Stanford's Department of Computer Science and Silicon Valley supply houses" (Wikipedia article on Sun Microsystems, accessed 06-12-2009).

The GRiD Compass 1100, introduced by Grid Systems Corporation, is probably the first commercial computer created in a "clamshell" laptop format, and one of the first truly portable machines.

The 1100 included a magnesium clamshell case with a screen that folded flat over the keyboard, a switching power supply, electro-luminescent display, non-volatile bubble memory, and a built-in modem.

Commodore issues the Commodore 64 — "the first cheap home computer."

The Commodore 64 looked like a bulky keyboard, but included color graphics, and excelled at playing early video games. Between 1982 and 1984 30,000,000 units were sold, making it the best-selling personal computer model of this era. Roughly 10,000 commercial programs were produced for this computer.

IBM introduces the Scanmaster 1, a mainframe computer terminal designed to scan, transmit and store images of documents electronically.

The TRS-80, Model 100, marketed in the U.S. by Tandy's Radio Shack, introduces the concept of a “laptop” computer.

More than 6,000,000 were sold. The introductory price was $1099.00.

Hewlett-Packard introduces the HP-150, one of the earliest commercially available touchscreen computers.

"The screen is not a touch screen in the strict sense, but a 9" Sony CRT surrounded by infrared emitters and detectors which detect the position of any non-transparent object on the screen. In the original HP-150, these emitters & detectors were placed within small holes located in the inside of the monitor's bezel (which resulted in the bottom series of holes sometimes filling with dust and causing the touch screen to fail; until the dust was vacuumed from the holes)" (Wikipedia article on HP-150, accessed 12-30-2009).

Apple Computer introduces the Macintosh ("Mac"), with a graphical user interface based on the Xerox Star system.

GRiD Systems, a subsidiary of Tandy Corporation, introduces the first commercially available tablet computer: the GRiDPad, which uses an operating system based on MS-DOS.

IBM develops scalable parallel systems, joining multiple computer processors and breaking down complex, data-intensive jobs to speed their completion.

AT&T introduces the AT&T EO Personal Communicator, the first tablet computer with wireless connectivity via a cellular phone.

The device was developed by GO/EO, a subsidiary of GO Corporation, both of which were acquired by AT&T in 1993.

"Two models, the Communicator 440 and 880 were produced and measured about the size of a small clipboard. Both were powered by the AT&T Hobbit chip, created by AT&T specifically for running code from the C programming language. They also contained a host of I/O ports - modem, parallel, serial, VGA out and SCSI. The device came with a wireless cellular network modem, a built-in microphone with speaker and a free subscription to AT&T EasyLink Mail for both fax and e-mail messages.

"Perhaps the most interesting part was the operating system, PenPoint OS, created by GO Corporation. Widely praised for its simplicity and ease of use, the OS never gained widespread use. Also equally compelling was the tightly integrated applications suite, Perspective, licensed to EO by Pensoft" (Wikipedia article on EO Personal Communicator, accessed 02-03-2010).

Supercomputer ASCI Blue-Pacific SST, jointly developed by the U.S. Energy Department’s Lawrence Livermore National Laboratory and IBM. It can perform 3.9 trillion calculations per second (15,000 times faster than the average desktop computer) and has over 2.6 trillion bytes of memory (80,000 times more than the average PC). It would take a person using a calculator 63,000 years to perform as many calculations as this computer can perform in a single second.

IBM announces the start of a five-year effort to build a massively parallel computer, Blue Gene, which will be 500 times more powerful than the world’s fastest computers at the time of the announcement.

Initially Blue Gene was applied to the study of bio-molecular phenomena such as protein folding.

The ASCI White supercomputer at the Lawrence Livermore National Laboratory in California is operational. An IBM system, it covers a space the size of two basketball courts and weighs 106 tons. It contains six trillion bytes (TB) of memory, almost 50,000 times greater than the average personal computer, and has more than 160 TB of Serial Disk System storage capacity—enough to hold six times the information stored in the 29 million books in the Library of Congress.

Charles Babbage’s Difference Engine No. 2, designed between 1847 and 1849, but never previously built, is completed and fully operational at the Science Museum, London. Built from Babbage’s engineering drawings roughly 150 years after it was originally designed, the finished machine weighs 5 tons and consists of 8000 machined parts, equally divided between the calculating and automatic printing and stereotyping apparatus. It is operated by turning hand-cranks.

The NASA supercomputer, Project Columbia, a cluster of 20 computers with a total of 10,240 processors, built by Silicon Graphics and Intel at NASA’s Ames Research Center, achieves sustained performance of 42.7 trillion calculations per second or teraflops.

“If you could do one calculation per second by hand, it would take you a million years to do what this machine does in a single second.” (NY Times).

The National Nuclear Security Administration (NNSA) announces that the BlueGene/L supercomputer built by IBM performs at 280.6 trillion operations per second (teraflops) on the Linpack benchmark, the standard by which major supercomputers are measured. This shatters the previous high mark of performing at 135.3 teraflops.

"IBM said in a statement that if every person in the world had a handheld calculator it would still take decades to perform the number of calculations Blue Gene performs every single second."

On the 60th anniversary of the public announcement of the ENIAC Computerworld publishes a previously unknown interview with J. Presper Eckert on the origins of the ENIAC.

The American military supercomputer called the Roadrunner, designed and built by scientists at I.B.M. and Los Alamos National Laboratories from components originally designed for video game machines, has processed more than 1.026 quadrillion calculations per second.

"To put the performance of the machine in perspective, Thomas P. D’Agostino, the administrator of the National Nuclear Security Administration, said that if all six billion people on earth used hand calculators and performed calculations 24 hours a day and seven days a week, it would take them 46 years to do what the Roadrunner can in one day."

The Cray XT5 supercomputer, known as Jaguar, at the National Center for Computational Sciences at Oak Ridge National Laborary, in Oak Ridge,Tennessee, became the world's fastest supercomputer by operating at 1.75 petaflop/s, or quadrillions of floating point operations per second, according to the Top500 Linpack benchmark.

Steve Jobs of Apple introduces the iPad, one-half inch thick, with a 9.7 inch, high resolution color touchscreen (multi-touch) diagonal display, powered by a 1-gigahertz Apple A4 chip and 16 to 64 gigabytes of flash storage, weighing 1.5 pounds and capable of running all iPhone applications, except presumably, the phone. The battery life is supposed to be 10 hours, and the device is supposed to hold a charge for 1 month in standby. The price starts at $499.00.

"The new device will have to be far better than the laptop and smartphone at doing important things: browsing the Web, doing e-mail, enjoying and sharing photographs, watching videos, enjoying your music collection, playing games, reading e-books. Otherwise, 'it has no reason for being.'" (http://bits.blogs.nytimes.com/2010/01/27/live-blogging-the-apple-product-announcement/?hp, accessed 01-27-2010).

Link to iPad on Apple website: http://www.apple.com/ipad/