¢BEFORE THE ATARI¢¢OR.....¢¢A SHORT HISTORY OF COMPUTERS¢¢by Alan Hitchen¢¢¢ Physical aids for calculation have existed since the abacus was invented in antiquity. Mechanical calculating devices are a more recent invention.¢¢ The first calculating machine is said to have been built by Wilhelm Schickard around 1623, but it was later destroyed in a fire. Luckily, he described its workings in correspondence with Johannes Kepler, thus enabling a reconstruction to be made of his Calculating Clock. This consisted of a version of Napiers Bones (Invented by John Napier in 1617) for multiplication sitting on top of the the mechanical device which carried out addition and subtraction.¢¢ Blaise Pascal created 'The Pascaline' mechanical calculator in 1642, to aid his father, who was a tax collector. It was a shoe box sized device that could add, subtract, divide and multiply, but it was unreliable so only a dozen or so were made, some of which still exist.¢¢ In the 1670's Gottfried von Leibnitz created a major improvement to the mechanism of calculators with the invention of the Leibnitz Wheel. Sadly, his own calculator, the Stepped Reckoner, was apparently never perfected, as the only surviving version is inoperative.¢¢ The first commercialiy produced calculator using the Leibnitz Wheel, The Arithmometer, was created by Charles Xavier Thomas De Colmar. It appeared in 1820, and around 1500 examples were sold up to 1880.¢¢ However, the most famous name in mechanical calculator design is Charles Babbage. He designed his Difference Engine in 1821, to compile logarithm tables. Unfortunately its complexity defeated the engineering of the day and it was abandoned in 1842.¢¢ However, in Sweden, Edvard Scheutz managed to build a working Difference Engine in 1843, based on the work of his father, Pehr. He built another in 1854.¢¢ Undeterred Babbage next designed the Analytical Engine. This was to be the worlds first programmable calculator. The machine had an input where numbers were entered on punch cards. The store held the numbers as required. The mill performed the arithmatic. The output printed the answer. The control unit was programmable for the type of calculation by punch cards. It too was never completed.¢¢ In 1885, Dorr E. Felt developed a calculator powered only by the action of pressing the keys. It was called the Comptometer, and was advertised as "the machine-gun of the office".¢¢ In 1892, William S. Burroughs' Adding and Listing Machine also used a keyboard, and was the first to produce a print out of the results. It became a best seller.¢¢ The American census of 1890 was processed by a punch card tabulator created by Herman Hollerith, founder of what was to become IBM. Mechanical calculators and tabulators were now familiar business tools.¢¢ In 1930, Dr. Vannevar Bush of the Massachusetts Institute of Technology produced his Differential Analyser. Copies of which were built at several universities, including a Meccano version built at Manchester. It was an electro-mechanical analog device, but it was still just a calculator, albeit a powerful one. However things were about to change.¢¢ In 1937, the brilliant mathematician Dr. Alan Turing published his paper 'On Computable Numbers, with an Application to the Entscheidungsproblem'. This paper lay out the concept of a machine that we now call a computer.¢¢ Research mathematician George Stibitz created his Model K (for Kitchen) computer in 1937. This was a device using relays that could add binary numbers. Developing the idea at Bell Labs, his Complex Number Calculator was completed in 1939. Bell was not very interested in developing it, but the U..S. Army was, they took delivery of five relay computers for ballistic computations. This range reached its peak in the BTL6 of 1949, though research continued into the 1950's.¢¢ Meanwhile in Germany, engineering student Konrad Zuse began work on a binary computer in 1936, to aid his work at Henschel Aircraft. The Z1 was a mechanical demonstration model using switches and bulbs. The Z2, completed in 1939, used relays. Military funding for a code breaking model was refused in 1940. Continuing to work almost unaided, Zuse and colleague Helmut Schreyer, built the Z3 in 1941. This used 2600 relays and was controlled by instructions on punch tape. The partly electronic Z4 was completed in 1945. His company, Zuse AG, founded in 1949 would form the basis of the German computer industry, becoming part of Seimens in 1967.¢¢ Back in America, Harvard engineer Howard Aiken had designed a relay computer, based on the ideas of Babbage, in 1937. He persuaded IBM to build the Harvard Mark I Automatic Sequence Controlled Calculator in 1939. It was finally completed in 1944. The Mark II arrived in 1947. The Mark III in 1950 and Mark IV in 1952. These relay computers were large, expensive, and only ten times as fast as a mechanical calculator, but they were reliable and could work 24 hours a day.¢¢ During the war America was desperate for accurate ballistic tables. Physics Professor John Mauchly proposed an electronic computer in 1942 but it was not until April 1943 the Army sanctioned the building of the Electronic Numerical Integrator Analyser and Computer - ENIAC. It finally entered service in February 1946. It was a huge device containing 18000 valves and weighing 30 tons! It could handle numbers of up to 20 digits and hold 10 of these numbers in its store. It was also very fast, up to 5000 calculations per second.¢¢ It had been thought that ENIAC was the first electronic computer. However the UK government revealed in 1975 that an electronic computer, code name Colossus, was operational at Bletchley Park in December 1943, and that ten units were operational at the end of the war. They replaced relay based machines that had been used from 1941. These 1500 valve code breaking machines were built by Professor M.H.A.Newman and T.H.Flowers, based on the ideas of Alan Turing. Development was continued on the Colossus design at the Radar and Telecommunications Research Establishment until 1963.¢¢ Work began on the sucessor to ENIAC, the Electronic Discrete Variable Automatic Calculator - EDVAC, in 1946. It was eventually completed in 1951, as John Mauchly and J.P.Eckert had left the project to form their own computer company. After creating BINAC for Northrop Aircraft in 1948, they produced the first commercial computer, UNIVAC 1, in 1951. Remington Rand bought the company in 1952 and sold 48 units, the last of which was turned off in 1970.¢¢ Mathematician John von Neumann had worked with Alan Turing in the late 30's. He published an influential paper on computer design in 1946. After working on EDVAC he created the IAS computer at the Institute of Advanced Studies at Princeton in 1952. This machine was to heavily influence future computer design.¢¢ At the National Physics Laboratory, Turing designed the very powerful Automatic Computing Engine - ACE, before joining the Manchester University team in 1948. ACE was eventually built in 1957 after the less ambitious Pilot ACE had been constructed. This was to form the basis for the English Electric range of commercial computers.¢¢ The first stored program computer was the Manchester University Mk 1 of 1948. This used a memory device known as a Williams tube. Manchester also collaborated to produce the Ferranti Mk 1 in 1951, which lead to the Pegasus of 1959, followed by the Mercury and Atlas models in the 60's.¢¢ Cambridge University produced EDSAC - Electronic Delayed Storage Automatic Calculator, a scaled down version of EDVAC, in 1949. This design influenced the development of the Lyons Electronic Office, which became the LEO 1 commercial computer of 1954. Leo Computers Limited were absorbed into English Electric in 1964. ¢¢ Birkbeck College produced experimental models based on the IAS design, which were the inspiration of the commercial units made by the British Tabulating Machine Co., now known as International Computers Limited.¢¢ The mighty IBM despite building the Harvard computers was not interested in this area until approached by the US government. It built the IBM 701, based on the IAS design, in 1953. It was surprised to get 18 orders for this model. Now convinced there was a demand for computers, the IBM 702 and 704 were launched in 1955 for commercial use.¢¢ Transistors, invented in 1947, were first used in the TX-O (Transistor eXperimental cOmputer) built at MIT in 1956. They finally supplanted the mighty valve in the IBM 7000 series of 1959.¢¢ Integrated circuits, created in 1958, first appeared in the IBM System/360 range of 1964. The BASIC programming language was invented by John Kemeny and Thomas Kurtz that year. ¢ The Intel Corporation, founded in 1968, pioneered the development of memory chips. And it was here that Marcian E.Hoff produced the first microprocessor, the 4004 (a 4-bit processor intended for use in a pocket calculator), in 1971.¢¢ The first home computer seems to be the Altair 8800, launched as a kit in December 1974, by Micro Instrumentation and Telemetry Systems. It used the Intel 8080 eight-bit microprocessor (1973) and had a miniscule 256 bytes of ram to work with. It cost $397.¢¢ In 1976 the 6502 microprocessor was launched by MOS Technology (based on the Motorola 6800 of 1974) and used in their KIM 1 (Keyboard Input Monitor 1) kit computer. The success of this crude device supposedly encouraged Commodore to launch the PET (Personal Electronic Transactor) in June 1977. ¢¢ The home computer boom was now just around the corner, the Atari 400 and 800 would soon arrive to do battle with a flood of micro's that came and went in the 80's. However, unlike many of its contemporaries, the Classic Atari range has not yet been forgotten by its faithful users.¢
