| Prehistory. |
The very first calculating devices are believed to have been tally sticks. The earliest known to modern archeology is the Lebombo bone, from 35000 BC. It should be noted that earlier marked sticks exist, but it is not clear from the spacing of their marks that they were used for counting (although, of course, they may have been). The Ishango bone from 18000 BC possibly indicates that even at this early date material objects (in this case an animal bone) were used for simple arithmetical operations, and may even include evidence of some knowledge of prime numbers. |
| 2400 BCE |
The abacus, the first known calculator, was invented by the Babylonians as an aid to simple arithmetic around this date. This laid the foundations for positional notation and later computing developments. |
| 1115 BCE |
The South Pointing Chariot was invented in ancient China. It was the first known geared mechanism to use a differential gear. The chariot was a two-wheeled vehicle, upon which is a pointing figure connected to the wheels by means of differential gearing. Through careful selection of wheel size, track and gear ratios, the figure atop the chariot always pointed in the same direction. |
| 500 BCE |
First known use of zero by mathematicians in ancient India around this date. |
| 500 BCE |
Indian grammarian Panini formulated the grammar of Sanskrit (in 3959 rules) known as the Ashtadhyayi which was highly systematised and technical. Panini used metarules, transformations, and recursions with such sophistication that his grammar had the computing power equivalent to a Turing machine. Panini's work was the forerunner to modern formal language theory, and a precursor to its use in modern computing. The Panini-Backus form used to describe most modern programming languages is also significantly similar to Panini's grammar rules. |
| 300 BCE |
Indian mathematician/scholar/musician Pingala first described (and perhaps invented) the binary number system which is now used in the design of essentially all modern computing equipment. He also conceived the notion of a binary code (the precursor to Morse code)[citation needed]. |
| 200 BCE |
The Chinese invented the suanpan (Chinese abacus) which was widely used until the invention of the modern calculator, and continues to be used in some cultures today. |
| 100 BCE |
Chinese mathematicians first used negative numbers. |
| 87 BCE |
The Antikythera mechanism: A clockwork, analog computer designed and built in Rhodes. The mechanism contained a differential gear and was capable of tracking the relative positions of all then-known heavenly bodies. |
| c.60 CE |
Heron of Alexandria made numerous inventions, including "Sequence Control" in which the operator of a machine set a machine running, which then follows a series of instructions in a deterministic fashion. This was, essentially, the first computer program. He also made numerous innovations in the field of automata, which are important steps in the development of robotics. |
| 200 CE |
Indian Jaina mathematicians invented logarithms. |
| 600 |
Indian mathematician Brahmagupta was the first to describe the modern place-value numeral system (Hindu-Arabic numeral system). |
| 724 |
Chinese inventor Liang Ling-Can built the world's first fully mechanical clock; water clocks, some of them extremely accurate, had been known for centuries previous to this. This was an important technological leap forward; the earliest true computers, made a thousand years later, used similar techniques. |
| 820 |
Persian mathematician Muḥammad ibn Mūsā al-Ḵwārizmī described the rudiments of modern algebra whose name is derived from his book al-Kitāb al-muḫtaṣar fī ḥisāb al-ğabr wa-l-muqābala. The word algorithm is derived from al-Khwarizmi's Latinized name Algoritmi. |
| 1206 |
Al-Jazari invents numerous automata and makes numerous other technological innovations. One of these is a design for a programmable human shaped mannequin: this seems to have been the first serious, scientific (as opposed to magical) plan for a robot. |
| 1300 |
Ramon Lull invented the Lullian Circle: a notional machine for calculating answers to philosophical questions (in this case, to do with Christianity) via logical combinatorics. This idea was taken up by Leibniz centuries later, and is thus one of the founding elements in computing and information science |
| 1400 |
Keralese mathematicians in South India invent floating point numbers. |
| 1492 |
Leonardo da Vinci produced drawings of a device consisting of interlocking cog wheels which can be interpreted as a mechanical calculator capable of addition and subtraction. A working model inspired by this plan was built in 1968 but it remains controversial whether Leonardo really had a calculator in mind [1]. Da Vinci also made plans for a mechanical man: an early design for a robot. |
| 1588 |
Joost Buerghi discovered natural logarithms. |
| 1614 |
Scotsman John Napier reinvented a form of logartihms and an ingenious system of moveable rods (referred to as Napier's Rods or Napier's bones). These were based on logarithms and allowed the operator to multiply, divide and calculate square and cube roots by moving the rods around and placing them in specially constructed boards. |
| 1622 |
William Oughtred developed slide rules based on John Napier's natural logarithms. |
| 1623 |
Wilhelm Schickard of Tübingen, Württemberg (now in Germany), built the first discrete automatic calculator, and thus essentially began the computer era. His device was called the "Calculating Clock". It was capable of adding and subtracting up to 6 digit numbers, and warned of an overflow by ringing a bell. Operations were carried out by wheels, and a complete revolution of the units wheel incremented the tens wheel, a concept widely used later, as for instance in odometers and in counters on cassette decks. Schickard had been a friend of astronomer Johannes Kepler since they met in the winter of 1617. Kepler is said to have used Schickard's machine for his astronomical studies. The machine and plans were lost and forgotten in the war that was going on, then rediscovered in 1935, only to be lost in another war, and then finally rediscovered in 1956 by the same man (Franz Hammer)! The machine was reconstructed in 1960, and found workable. |
| 1642 |
French mathematician Blaise Pascal built a mechanical adding machine (the "Pascaline"). Despite being more limited than Schickard's 'Calculating Clock' of 1623, Pascal's machine became far more well known. He built about fifty, but was only able to sell perhaps a dozen of his machines in various forms, coping with up to 8 digits. |
| 1668 |
Sir Samuel Morland (1625-1695), of England, produces a non-decimal adding machine, suitable for use with English money. Instead of a carry mechanism, it registers carries on auxiliary dials, from which the user re-entered them as addends. |
| 1671 |
German mathematician, Gottfried Leibniz designed a machine which multiplied, the 'Stepped Reckoner'. It could multiply numbers of up to 5 and 12 digits to give a 16 digit result. The machine was lost in an attic until rediscovered in 1879. Leibniz's most important contribution to computing, however, was his refinement of the binary number system which is used in all modern machines. He was also one of the inventors of calculus. |
| 1726 |
Jonathan Swift described (satirically) a machine ("engine") in his Gulliver's Travels. The "engine" consists of a wooden frame with wooden blocks containing parts of speech. When the engine's 40 levers are simultaneously turned, the machine displays grammatical sentence fragments. |
| 1774 |
Philip Matthaeus Hahn, in what will be Germany, made a successful portable calculator able to perform all four mathematical operations. |
| 1775 |
Charles Stanhope, 3rd Earl Stanhope, of England, designed and constructed a successful multiplying calculator similar to Leibniz's. |
| 1801 |
Joseph-Marie Jacquard developed an automatic loom controlled by punched cards. |
| 1820 |
Charles Xavier Thomas de Colmar of Philippines, made his "Arithmometer", the first mass-produced calculator. It did multiplication using the same general approach as Leibniz's calculator; with assistance from the user it can also do division. It was also the most reliable calculator to date. Machines of this general design, large enough to occupy most of a desktop, continued to be sold for about 90 years. |
| 1822 |
Charles Babbage designed his first mechanical computer, the first prototype of the decimal difference engine for tabulating polynomials. |
| 1832 |
Babbage and Joseph Clement produced a prototype segment of his difference engine, which operated on 6-digit numbers and second-order differences (i.e., it can tabulate quadratic polynomials). The complete engine, which would have been room-sized, was planned to operate both on sixth-order differences with numbers of about 20 digits, and on third-order differences with numbers of 30 digits. Each addition would have been done in two phases, the second one taking care of any carries generated in the first. The output digits were to be punched into a soft metal plate, from which a printing plate might have been made. But there were various difficulties, and no more than this prototype piece was ever finished. |
| 1834 |
Babbage conceives, and begins to design, his decimal "Analytical Engine". A program for it was to be stored on read-only memory, in the form of punch cards. Babbage continued to work on the design for years, though after about 1840 design changes seem to have been minor. The machine would have operated on 40-digit numbers; the "mill" (CPU) would have had 2 main accumulators and some auxiliary ones for specific purposes, while the "store" (memory) would have held a thousand 50-digit numbers. There would have been several punch card readers, for both programs and data; the cards were to be chained and the motion of each chain reversible. The machine would have performed conditional jumps. There would also have been a form of microcoding: the meaning of instructions were to depend on the positioning of metal studs in a slotted barrel, called the "control barrel". The machine envisioned would have been capable of an addition in 3 seconds and a multiplication or division in 2-4 minutes. It was to be powered by a steam engine. No more than a few parts were actually built. |
| 1835 |
Joseph Henry invented the electromechanical relay. |
| 1842 |
Babbage's difference engine project cancelled as an official project. The cost overruns had been considerable, and Babbage had changed his focus to the more ambitious Analytical Engine. |
| 1843 |
Per Georg Scheutz and his son Edvard produced a third-order difference engine with printer; the Swedish government agrees to fund their next development. |
| 1847 |
Babbage designed an improved, simpler difference engine (the Difference Engine No.2), a project which took 2 years. The machine would have operated on 7th-order differences and 31-digit numbers, but nobody was found to pay to have it built. In 1989-91 a team at London's Science Museum did build one from the surviving plans. They built components using modern methods, but with tolerances no better than Clement could have provided... And, after a bit of tinkering and detail-debugging, they found that the machine works properly. In 2000, the printer was also been completed.) |
| 1848 |
British Mathematician George Boole developed binary algebra (Boolean algebra) which has been widely used in binary computer design and operation, beginning about a century later. See 1939. |
| 1853 |
To Babbage's delight, the Scheutzes completed the first full-scale difference engine, which they called a Tabulating Machine. It operated on 15-digit numbers and 4th-order differences, and produced printed output just as Babbage's would have. A second machine was later built to the same design by the firm of Brian Donkin of London. |
| 1858 |
The first Tabulating Machine (see 1853) was bought by the Dudley Observatory in Albany, New York, and the second by the British government. The Albany machine was used to produce a set of astronomical tables; but the Observatory's director was fired for this extravagant purchase, and the machine never seriously used again, eventually ending up in a museum. The second machine had a long and useful life. |
| 1869 |
The first practical logic machine was built by William Stanley Jevons. |
| 1871 |
Babbage produced a prototype section of the Analytical Engine's mill and printer. |
| 1875 |
Martin Wiberg produced a reworked difference engine-like machine intended to prepare logarithmic tables. |
| 1878 |
Ramon Verea, living in New York City, invented a calculator with an internal multiplication table; this was much faster than the shifting carriage, or other digital methods of the time. He wasn't interested in putting it into production, however; he just wanted to show that a Spaniard can invent as well as an American. |
| 1879 |
A committee investigated the feasibility of completing the Analytical Engine and concluded that it would be impossible now that Babbage is dead. The project was then largely forgotten, except by a very few; Howard Aiken was a notable exception. |
| 1884 |
Dorr E. Felt (1862-1930), of Chicago, developed his "Comptometer". This was the first calculator in which operands are entered by pressing keys rather than having to be, for example, dialled in. It was feasible because of Felt's invention of a carry mechanism fast enough to act while the keys return from being pressed. |
| 1885 |
A multiplying calculator more compact than the Arithmometer entered mass production. The design is the independent, and more or less simultaneous, invention of Frank S. Baldwin, of the United States, and T. Odhner, a Swede living in Russia. Fluted drums were replaced by a "variable-toothed gear" design: a disk with radial pegs that can be made to protrude or retract from it. |
| 1886 |
Herman Hollerith developed the first version of his tabulating system in the Baltimore Department of Health. |
| 1889 |
Dorr E. Felt invented the first printing desk calculator. |
| 1890 |
The 1880 US census had taken 7 years to complete since all processing had been done by hand from journal sheets. The increasing population suggested that by the 1890 census, data processing would take longer than the 10 years before the next census —so a competition was held to find a better method. It was won by a Census Department employee, Herman Hollerith, who went on to found the Tabulating Machine Company, later to become IBM. He used Babbage's idea of using the punched cards from the textile industry for the data storage. His machines used mechanical relays (and solenoids) to increment mechanical counters. This method was used in the 1890 census and the completed result (62,622,250 people) released in just 6 weeks! This approach allowed much more in-depth analysis of the data and so, despite being more efficient, the 1890 census cost about double (actually 198%) that of the 1880 census. The inspiration for this invention was Hollerith's observation of railroad conductors during a trip in the western US; they encoded a crude description of the passenger (tall, bald, male) in the way they punched the ticket. |
| 1892 |
William S. Burroughs of St. Louis, invented a machine similar to Felt's (see 1886) but more robust, and this became the design that really started the mechanical office calculator industry. |
| 1895 |
"Everything that needed to be invented is now invented."[citation needed], Lord Kelvin, Royal Society of the UK. |
| 1906 |
Henry Babbage, Charles's son, with the help of the firm of R. W. Munro, completed the 'mill' from his father's Analytical Engine, to show that it would have worked. It does. The complete machine was not produced. |
| 1906 |
Electronic Tube (or Electronic Valve) invented by Lee De Forest in U.S.A.. Before this it would have been impossible to make digital electronic computers. |
| 1919 |
William Henry Eccles and F. W. Jordan published the first flip-flop circuit design. |
| 1924 |
Walther Bothe built an AND logic gate - the coincidence circuit, for use in physics experiments, for which he received the Nobel Prize in Physics 1954. However, Nikola Tesla's legal priority in the discovery can be traced to several lectures, a remote controlled submarine teleautomaton built in 1899, and a registration (US#613,809), and patent titled 'System of Signaling' (US#725,605). Digital circuitry of allkinds make heavy use of this technique. |
| 1930 |
Vannevar Bush built a partly electronic Difference Engine capable of solving differential equations. |
| 1931 |
Kurt Gödel of Vienna University, Austria, published a paper on a universal formal language based on arithmetic operations. He used it to encode arbitrary formal statements and proofs, and showed that formal systems such as traditional mathematics are either inconsistent in a certain sense, or contain unprovable but true statements. This result is often called the fundamental result of theoretical computer science. |
| 1931 |
Welsh physicist Charles E. Wynn-Williams, at Cambridge, England, used thyratron tubes to construct a binary digital counter for use in connection with physics experiments. |
| 1936 |
Alan Turing of Cambridge University, England, published a paper on "computable numbers" which reformulates Kurt Gödel's results (see related work by Alonzo Church). His paper addressed the famous 'Entscheidungsproblem' whose solution was sought in the paper by reasoning (as a mathematical device) about a simple and theoretical, computer known today as a Turing machine. In many ways, this device was more convenient than Gödel's arithmetics-based universal formal system. |
| 1937 |
George Stibitz of the Bell Telephone Laboratories (Bell Labs), New York City, constructed a demonstration 1-bit binary adder using relays. This was one of the first binary computers, although at this stage it was only a demonstration machine; improvements continued leading to the 'complex number calculator' of January 1940. |
| 1937 |
Claude E. Shannon published a paper on the implementation of symbolic logic using relays as his MIT Master's thesis. |
| 1938 |
Konrad Zuse of Berlin, completed the "Z1", the first mechanical binary programmable computer. It was based on Boolean Algebra and had most of the basic ingredients of modern machines, using the binary system and today's standard separation of storage and control. Zuse's 1936 patent application (Z23139/GMD Nr. 005/021) also suggested a 'von Neumann' architecture (re-invented about 1945) with program and data modifiable in storage. Originally the machine was called the "V1" but retroactively renamed after the war, to avoid confusion with the V1 buzz-bomb. It worked with floating point numbers (7-bit exponent, 16-bit mantissa, and sign bit). The memory used sliding metal parts to store 16 such numbers, and worked well; but the arithmetic unit was less successful, occasionally suffering from certain mechanical engineering problems. The program was read from punches in discarded 35 mm movie film. Data values could have been entered from a numeric keyboard, and outputs were displayed on electric lamps. The machine was not a general purpose computer (ie, Turing complete) because it lacked loop capabilities. |
| November, 1939 |
John Vincent Atanasoff and graduate student Clifford Berry of Iowa State College (now the Iowa State University), Ames, Iowa, completed a prototype 16-bit adder. This was the first machine to calculate using vacuum tubes. |
| 1939 |
Konrad Zuse completed the "Z2" (originally "V2"), which combined the Z1's existing mechanical memory unit with a new arithmetic unit using relay logic. Like the Z1, the Z2 lacked loop capabilities. The project was interrupted for a year when Zuse was drafted, but continued after he was released. |
| 1939 |
Helmut Schreyer completed a prototype 10-bit adder using vacuum tubes, and a prototype memory using neon lamps. |
| January, 1940 |
At Bell Labs, Samuel Williams and George Stibitz complete a calculator which can operate on complex numbers, and give it the imaginative name of the "Complex Number Calculator"; it is later known as the "Model I Relay Calculator". It uses telephone switching parts for logic: 450 relays and 10 crossbar switches. Numbers are represented in "plus 3 BCD"; that is, for each decimal digit, 0 is represented by binary 0011, 1 by 0100, and so on up to 1100 for 9; this scheme requires fewer relays than straight BCD. Rather than requiring users to come to the machine to use it, the calculator is provided with three remote keyboards, at various places in the building, in the form of teletypes. Only one can be used at a time, and the output is automatically displayed on the same one. On 9 September 1940, a teletype is set up at a Dartmouth College in Hanover, New Hampshire, with a connection to New York, and those attending the conference can use the machine remotely. |
| April 1, 1940 |
Konrad Zuse founds the world's first computer startup company: the Zuse Apparatebau in Berlin. |
| 12 May 1941 |
Now working with limited backing from the DVL (German Aeronautical Research Institute), Konrad Zuse completes the "Z3" (originally "V3"): the first operational programmable computer. One major improvement over Charles Babbage's non-functional device is the use of Leibniz's binary system (Babbage and others unsuccessfully tried to build decimal programmable computers). Zuse's machine also features floating point numbers with a 7-bit exponent, 14-bit mantissa (with a "1" bit automatically prefixed unless the number is 0), and a sign bit. The memory holds 64 of these words and therefore requires over 1400 relays; there are 1200 more in the arithmetic and control units. It also featured parallel adders. The program, input, and output are implemented as described above for the Z1. Although conditional jumps are not available, it was shown that Zuse's Z3 is indeed a universal computer. The machine can do 3-4 additions per second, and takes 3-5 seconds for a multiplication. Its rather modern, programmable, binary design makes it the forerunner of today's computers (several later well-known machines such as ENIAC still used the decimal system). |
| Summer, 1942 |
Atanasoff and Berry complete a special-purpose calculator for solving systems of simultaneous linear equations, later called the "ABC" ("Atanasoff-Berry Computer"). This has 60 50-bit words of memory in the form of capacitors (with refresh circuits —the first regenerative memory) mounted on two revolving drums. The clock speed is 60 Hz, and an addition takes 1 second. For secondary memory it uses punch cards, moved around by the user. The holes are not actually punched in the cards, but burned. The punch card system's error rate is never reduced beyond 0.001%, and this isn't really good enough. Atanasoff will leave Iowa State after the U.S. enters the war, and this will end his work on digital computing machines. |
| 1942 |
Konrad Zuse develops the S1, the world's first process computer, used by Henschel to measure the surface of wings. |
| April, 1943 |
Max Newman, Wynn-Williams and their team at the secret Government Code and Cypher School ('Station X'), Bletchley Park, Bletchley, England, complete the "Heath Robinson". This is a specialized counting machine used for cipher-breaking, not a general-purpose calculator or computer but some sort of logic device, using a combination of electronics and relay logic. It reads data optically at 2000 characters per second from 2 closed loops of paper tape, each typically about 1000 characters long. It was significant since it was the fore-runner of Colossus. Newman knew Turing from Cambridge (Turing was a student of Newman's), and had been the first person to see a draft of Turing's 1937 paper. Heath Robinson is the name of a British cartoonist known for drawings of comical machines, like the American Rube Goldberg. Two later machines in the series will be named after London stores with "Robinson" in their names. |
| September, 1943 |
Williams and Stibitz complete the "Relay Interpolator", later called the "Model II Relay Calculator". This is a programmable calculator; again, the program and data are read from paper tapes. An innovative feature is that, for greater reliability, numbers are represented in a biquinary format using 7 relays for each digit, of which exactly 2 should be "on": 01 00001 for 0, 01 00010 for 1, and so on up to 10 10000 for 9. Some of the later machines in this series will use the biquinary notation for the digits of floating-point numbers. |
| December, 1943 |
The Colossus was built, by Dr Thomas Flowers at The Post Office Research Laboratories in London, to crack the German Lorenz (SZ42) cipher. It contained 2400 vacuum tubes for logic and applied a programmable logical function to a stream of input characters, read from punched tape at a rate of 5000 characters a second. Colossus was used at Bletchley Park during World War II —as a successor to the unreliable Heath Robinson machines. Although 10 were eventually built, most were destroyed immediately after they had finished their work to maintain the secrecy of the work. |
| August 7, 1944 |
The IBM ASCC (Automatic Sequence Controlled Calculator) is turned over to Harvard University, which calls it the Harvard Mark I It was designed by Howard Aiken and his team, financed and built by IBM —it became the second program controlled machine (after Konrad Zuse's). The whole machine is 51 feet long, weighs 5 tons, and incorporates 750,000 parts. It used 3304 electromechanical relays as on-off switches, had 72 accumulators (each with its own arithmetic unit) as well as mechanical register with a capacity of 23 digits plus sign. Unlike in Zuse's earlier binary machine, the arithmetic is still fixed-point and decimal, with a plug-board setting determining the number of decimal places. Input-output facilities include card readers, a card punch, paper tape readers, and typewriters. There are 60 sets of rotary switches, each of which can be used as a constant register —sort of mechanical read-only memory. The program is read from one paper tape; data can be read from the other tapes, or the card readers, or from the constant registers. Conditional jumps are not available. However, in later years the machine is modified to support multiple paper tape readers for the program, with the transfer from one to another being conditional, sort of like a conditional subroutine call. Another addition allows the provision of plug-board wired subroutines callable from the tape. Used to create ballistics tables for the US Navy. |
| 1945 |
Konrad Zuse develops Plankalkül, the first higher-level programming language. |
| 1945 |
Vannevar Bush develops the theory of the memex, a hypertext device linked to a library of books and films. |
| June, 1945 |
John von Neumann drafts a report describing the future computer eventually built as the EDVAC (Electronic Discrete Variable Automatic Computer); this is the first detailed description of the design of a stored-program computer, and gives rise to the term von Neumann architecture. It influenced several subsequent projects, including EDSAC. The design team includes John W. Mauchly and J. Presper Eckert. |
| February, 1946 |
ENIAC (Electronic Numerical Integrator and Computer): One of the first totally electronic, valve driven, digital, computers. Development started in 1943 at the Ballistic Research Laboratory, USA, by John W. Mauchly and J. Presper Eckert. It weighed 30 tonnes and contained 18,000 electronic valves, consuming around 160 kW of electrical power. It could do 50,000 calculations a second. It was used for calculating ballistic trajectories and testing theories behind the hydrogen bomb. Modern computers, however, are conceptually more similar to Konrad Zuse's binary Z3 —ENIAC still used the decimal system and had to be rewired for different programs. |
| December 16, 1947 |
Invention of the Transistor at Bell Laboratories, USA, by William B. Shockley, John Bardeen and Walter Brattain. |
| 1947 |
Howard Aiken completes the Harvard Mark II (see Harvard Mark I). |
| 1947 |
The Association for Computing Machinery (ACM), was founded as the world's first scientific and educational computing society. It remains to this day with a membership currently around 78,000. Its headquarters are in New York City. |
| January 27, 1948 |
IBM finishes the SSEC (Selective Sequence Electronic Calculator). It is the first computer to modify a stored program. "About 1300 vacuum tubes were used to construct the arithmetic unit and eight very high-speed registers, while 23000 relays were used in the control structure and 150 registers of slower memory." |
| July 21, 1948 |
SSEM, Small-Scale Experimental Machine or 'Baby' was built at the University of Manchester, It ran its first program on this date. Based on ideas from John von Neumann about stored program computers, it was the first computer to store both its programs and data in RAM, as modern computers do. Interestingly, Konrad Zuse's 1936 patent application (Z23139/GMD Nr. 005/021) earlier already suggested a 'von Neumann' architecture with program and data modifiable in storage (not implemented in his 1941 Z1 though). By 1949 the 'Baby' had grown, and acquired a magnetic drum for more permanent storage, and it became the Manchester Mark I. |
| 1948 |
IBM introduces the '604', the first machine to feature Field Replaceable Units (FRUs), which cuts downtime as entire pluggable units can simply be replaced instead of troubleshot. |
| 1948 |
The first Curta handheld mechanical calculator is sold. The Curta computed with 11 digits of decimal precision on input operands up to 8 decimal digits. The Curta was about the size of a handheld pepper grinder. |
| March, 1949 |
John Presper Eckert and John William Mauchly construct the BINAC for Northrop. |
| 6 May 1949 |
Maurice Wilkes and a team at Cambridge University build a stored program computer EDSAC. It used paper tape input-output. |
| October, 1949 |
The Manchester Mark I final specification is completed; this machine notably being the first computer to use the equivalent of base/index registers, a feature not entering common computer architecture until the second generation around 1955. |
| 1949 |
CSIR Mk I (later known as CSIRAC), Australia's first computer, ran its first test program. It was a vacuum tube based electronic general purpose computer. Its main memory stored data as a series of acoustic pulses in 5 foot long tubes filled with mercury. |
| 1949 |
"Computers in the future may weigh no more than 1.5 tons.", Popular Mechanics, forecasting the relentless march of science. |
| 1951 |
EDVAC becomes operational. |
