History of Modern Computer

High-Speed Memory

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The EDVAC and ACE proposals both advocated the use of mercury-filled tubes, called ‘delay lines’, for high-speed internal memory. This form of memory is known as acoustic memory. Delay lines had initially been developed for echo cancellation in radar; the idea of using them as memory devices originated with Eckert at the Moore School. Here is Turing's description:

It is proposed to build "delay line" units consisting of mercury … tubes about 5′ long and 1″ in diameter in contact with a quartz crystal at each end. The velocity of sound in … mercury … is such that the delay will be 1.024 ms. The information to be stored may be considered to be a sequence of 1024 ‘digits’ (0 or 1) … These digits will be represented by a corresponding sequence of pulses. The digit 0 … will be represented by the absence of a pulse at the appropriate time, the digit 1 … by its presence. This series of pulses is impressed on the end of the line by one piezo-crystal, it is transmitted down the line in the form of supersonic waves, and is reconverted into a varying voltage by the crystal at the far end. This voltage is amplified sufficiently to give an output of the order of 10 volts peak to peak and is used to gate a standard pulse generated by the clock. This pulse may be again fed into the line by means of the transmitting crystal, or we may feed in some altogether different signal. We also have the possibility of leading the gated pulse to some other part of the calculator, if we have need of that information at the time. Making use of the information does not of course preclude keeping it also. (Turing [1945], p. 375)

Mercury delay line memory was used in EDSAC, BINAC, SEAC, Pilot Model ACE, EDVAC, DEUCE, and full-scale ACE (1958). The chief advantage of the delay line as a memory medium was, as Turing put it, that delay lines were "already a going concern" (Turing [1947], p. 380). The fundamental disadvantages of the delay line were that random access is impossible and, moreover, the time taken for an instruction, or number, to emerge from a delay line depends on where in the line it happens to be.

In order to minimize waiting-time, Turing arranged for instructions to be stored not in consecutive positions in the delay line, but in relative positions selected by the programmer in such a way that each instruction would emerge at exactly the time it was required, in so far as this was possible. Each instruction contained a specification of the location of the next. This system subsequently became known as ‘optimum coding’. It was an integral feature of every version of the ACE design. Optimum coding made for difficult and untidy programming, but the advantage in terms of speed was considerable. Thanks to optimum coding, the Pilot Model ACE was able to do a floating point multiplication in 3 milliseconds (Wilkes's EDSAC required 4.5 milliseconds to perform a single fixed point multiplication).

In the Williams tube or electrostatic memory, previously mentioned, a two-dimensional rectangular array of binary digits was stored on the face of a commercially-available cathode ray tube. Access to data was immediate. Williams tube memories were employed in the Manchester series of machines, SWAC, the IAS computer, and the IBM 701, and a modified form of Williams tube in Whirlwind I (until replacement by magnetic core in 1953).

Drum memories, in which data was stored magnetically on the surface of a metal cylinder, were developed on both sides of the Atlantic. The initial idea appears to have been Eckert's. The drum provided reasonably large quantities of medium-speed memory and was used to supplement a high-speed acoustic or electrostatic memory. In 1949, the Manchester computer was successfully equipped with a drum memory; this was constructed by the Manchester engineers on the model of a drum developed by Andrew Booth at Birkbeck College, London.

The final major event in the early history of electronic computation was the development of magnetic core memory. Jay Forrester realised that the hysteresis properties of magnetic core (normally used in transformers) lent themselves to the implementation of a three-dimensional solid array of randomly accessible storage points. In 1949, at Massachusetts Institute of Technology, he began to investigate this idea empirically. Forrester's early experiments with metallic core soon led him to develop the superior ferrite core memory. Digital Equipment Corporation undertook to build a computer similar to the Whirlwind I as a test vehicle for a ferrite core memory. The Memory Test Computer was completed in 1953. (This computer was used in 1954 for the first simulations of neural networks, by Belmont Farley and Wesley Clark of MIT's Lincoln Laboratory (see Copeland and Proudfoot [1996]).

Once the absolute reliability, relative cheapness, high capacity and permanent life of ferrite core memory became apparent, core soon replaced other forms of high-speed memory. The IBM 704 and 705 computers (announced in May and October 1954, respectively) brought core memory into wide use.

Other Notable Early Computers

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Other notable early stored-program electronic digital computers were:

EDSAC, 1949, built at Cambridge University by Maurice Wilkes
BINAC, 1949, built by Eckert's and Mauchly's Electronic Control Co., Philadelphia (opinions differ over whether BINAC ever actually worked)
Whirlwind I, 1949, Digital Computer Laboratory, Massachusetts Institute of Technology, Jay Forrester
SEAC, 1950, US Bureau of Standards Eastern Division, Washington D.C., Samuel Alexander, Ralph Slutz
SWAC, 1950, US Bureau of Standards Western Division, Institute for Numerical Analysis, University of California at Los Angeles, Harry Huskey
UNIVAC, 1951, Eckert-Mauchly Computer Corporation, Philadelphia (the first computer to be available commercially in the U.S.)
the IAS computer, 1952, Institute for Advanced Study, Princeton University, Julian Bigelow, Arthur Burks, Herman Goldstine, von Neumann, and others (thanks to von Neumann's publishing the specifications of the IAS machine, it became the model for a group of computers known as the Princeton Class machines; the IAS computer was also a strong influence on the IBM 701)
IBM 701, 1952, International Business Machine's first mass-produced electronic stored-program computer.

ENIAC and EDVAC

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The first fully functioning electronic digital computer to be built in the U.S. was ENIAC, constructed at the Moore School of Electrical Engineering, University of Pennsylvania, for the Army Ordnance Department, by J. Presper Eckert and John Mauchly. Completed in 1945, ENIAC was somewhat similar to the earlier Colossus, but considerably larger and more flexible (although far from general-purpose). The primary function for which ENIAC was designed was the calculation of tables used in aiming artillery. ENIAC was not a stored-program computer, and setting it up for a new job involved reconfiguring the machine by means of plugs and switches. For many years, ENIAC was believed to have been the first functioning electronic digital computer, Colossus being unknown to all but a few.

In 1944, John von Neumann joined the ENIAC group. He had become ‘intrigued’ (Goldstine's word, [1972], p. 275) with Turing's universal machine while Turing was at Princeton University during 1936–1938. At the Moore School, von Neumann emphasised the importance of the stored-program concept for electronic computing, including the possibility of allowing the machine to modify its own program in useful ways while running (for example, in order to control loops and branching). Turing's paper of 1936 (‘On Computable Numbers, with an Application to the Entscheidungsproblem’) was required reading for members of von Neumann's post-war computer project at the Institute for Advanced Study, Princeton University (letter from Julian Bigelow to Copeland, 2002; see also Copeland [2004], p. 23). Eckert appears to have realised independently, and prior to von Neumann's joining the ENIAC group, that the way to take full advantage of the speed at which data is processed by electronic circuits is to place suitably encoded instructions for controlling the processing in the same high-speed storage devices that hold the data itself (documented in Copeland [2004], pp. 26–7). In 1945, while ENIAC was still under construction, von Neumann produced a draft report, mentioned previously, setting out the ENIAC group's ideas for an electronic stored-program general-purpose digital computer, the EDVAC (von Neuman [1945]). The EDVAC was completed six years later, but not by its originators, who left the Moore School to build computers elsewhere. Lectures held at the Moore School in 1946 on the proposed EDVAC were widely attended and contributed greatly to the dissemination of the new ideas.

Von Neumann was a prestigious figure and he made the concept of a high-speed stored-program digital computer widely known through his writings and public addresses. As a result of his high profile in the field, it became customary, although historically inappropriate, to refer to electronic stored-program digital computers as ‘von Neumann machines’.

The Los Alamos physicist Stanley Frankel, responsible with von Neumann and others for mechanising the large-scale calculations involved in the design of the atomic bomb, has described von Neumann's view of the importance of Turing's 1936 paper, in a letter:

I know that in or about 1943 or ‘44 von Neumann was well aware of the fundamental importance of Turing's paper of 1936 … Von Neumann introduced me to that paper and at his urging I studied it with care. Many people have acclaimed von Neumann as the "father of the computer" (in a modern sense of the term) but I am sure that he would never have made that mistake himself. He might well be called the midwife, perhaps, but he firmly emphasized to me, and to others I am sure, that the fundamental conception is owing to Turing, in so far as not anticipated by Babbage … Both Turing and von Neumann, of course, also made substantial contributions to the "reduction to practice" of these concepts but I would not regard these as comparable in importance with the introduction and explication of the concept of a computer able to store in its memory its program of activities and of modifying that program in the course of these activities. (Quoted in Randell [1972], p. 10)

The Manchester Machine

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The earliest general-purpose stored-program electronic digital computer to work was built in Newman's Computing Machine Laboratory at Manchester University. The Manchester ‘Baby’, as it became known, was constructed by the engineers F.C. Williams and Tom Kilburn, and performed its first calculation on 21 June 1948. The tiny program, stored on the face of a cathode ray tube, was just seventeen instructions long. A much enlarged version of the machine, with a programming system designed by Turing, became the world's first commercially available computer, the Ferranti Mark I. The first to be completed was installed at Manchester University in February 1951; in all about ten were sold, in Britain, Canada, Holland and Italy.

The fundamental logico-mathematical contributions by Turing and Newman to the triumph at Manchester have been neglected, and the Manchester machine is nowadays remembered as the work of Williams and Kilburn. Indeed, Newman's role in the development of computers has never been sufficiently emphasised (due perhaps to his thoroughly self-effacing way of relating the relevant events).

It was Newman who, in a lecture in Cambridge in 1935, introduced Turing to the concept that led directly to the Turing machine: Newman defined a constructive process as one that a machine can carry out (Newman in interview with Evans, op. cit.). As a result of his knowledge of Turing's work, Newman became interested in the possibilities of computing machinery in, as he put it, ‘a rather theoretical way’. It was not until Newman joined GC&CS in 1942 that his interest in computing machinery suddenly became practical, with his realisation that the attack on Tunny could be mechanised. During the building of Colossus, Newman tried to interest Flowers in Turing's 1936 paper — birthplace of the stored-program concept - but Flowers did not make much of Turing's arcane notation. There is no doubt that by 1943, Newman had firmly in mind the idea of using electronic technology in order to construct a stored-program general-purpose digital computing machine.

In July of 1946 (the month in which the Royal Society approved Newman's application for funds to found the Computing Machine Laboratory), Freddie Williams, working at the Telecommunications Research Establishment, Malvern, began the series of experiments on cathode ray tube storage that was to lead to the Williams tube memory. Williams, until then a radar engineer, explains how it was that he came to be working on the problem of computer memory:

[O]nce [the German Armies] collapsed … nobody was going to care a toss about radar, and people like me … were going to be in the soup unless we found something else to do. And computers were in the air. Knowing absolutely nothing about them I latched onto the problem of storage and tackled that. (Quoted in Bennett 1976.)

Newman learned of Williams' work, and with the able help of Patrick Blackett, Langworthy Professor of Physics at Manchester and one of the most powerful figures in the University, was instrumental in the appointment of the 35 year old Williams to the recently vacated Chair of Electro-Technics at Manchester. (Both were members of the appointing committee (Kilburn in interview with Copeland, 1997).) Williams immediately had Kilburn, his assistant at Malvern, seconded to Manchester. To take up the story in Williams' own words:

[N]either Tom Kilburn nor I knew the first thing about computers when we arrived in Manchester University. We'd had enough explained to us to understand what the problem of storage was and what we wanted to store, and that we'd achieved, so the point now had been reached when we'd got to find out about computers … Newman explained the whole business of how a computer works to us. (F.C. Williams in interview with Evans [1976])

Elsewhere Williams is explicit concerning Turing's role and gives something of the flavour of the explanation that he and Kilburn received:

Tom Kilburn and I knew nothing about computers, but a lot about circuits. Professor Newman and Mr A.M. Turing … knew a lot about computers and substantially nothing about electronics. They took us by the hand and explained how numbers could live in houses with addresses and how if they did they could be kept track of during a calculation. (Williams [1975], p. 328)

It seems that Newman must have used much the same words with Williams and Kilburn as he did in an address to the Royal Society on 4th March 1948:

Professor Hartree … has recalled that all the essential ideas of the general-purpose calculating machines now being made are to be found in Babbage's plans for his analytical engine. In modern times the idea of a universal calculating machine was independently introduced by Turing … [T]he machines now being made in America and in this country … [are] in certain general respects … all similar. There is provision for storing numbers, say in the scale of 2, so that each number appears as a row of, say, forty 0's and 1's in certain places or "houses" in the machine. … Certain of these numbers, or "words" are read, one after another, as orders. In one possible type of machine an order consists of four numbers, for example 11, 13, 27, 4. The number 4 signifies "add", and when control shifts to this word the "houses" H11 and H13 will be connected to the adder as inputs, and H27 as output. The numbers stored in H11 and H13 pass through the adder, are added, and the sum is passed on to H27. The control then shifts to the next order. In most real machines the process just described would be done by three separate orders, the first bringing [H11] (=content of H11) to a central accumulator, the second adding [H13] into the accumulator, and the third sending the result to H27; thus only one address would be required in each order. … A machine with storage, with this automatic-telephone-exchange arrangement and with the necessary adders, subtractors and so on, is, in a sense, already a universal machine. (Newman [1948], pp. 271–272)

Following this explanation of Turing's three-address concept (source 1, source 2, destination, function) Newman went on to describe program storage (‘the orders shall be in a series of houses X1, X2, …’) and conditional branching. He then summed up:

From this highly simplified account it emerges that the essential internal parts of the machine are, first, a storage for numbers (which may also be orders). … Secondly, adders, multipliers, etc. Thirdly, an "automatic telephone exchange" for selecting "houses", connecting them to the arithmetic organ, and writing the answers in other prescribed houses. Finally, means of moving control at any stage to any chosen order, if a certain condition is satisfied, otherwise passing to the next order in the normal sequence. Besides these there must be ways of setting up the machine at the outset, and extracting the final answer in useable form. (Newman [1948], pp. 273–4)

In a letter written in 1972 Williams described in some detail what he and Kilburn were told by Newman:

About the middle of the year [1946] the possibility of an appointment at Manchester University arose and I had a talk with Professor Newman who was already interested in the possibility of developing computers and had acquired a grant from the Royal Society of £30,000 for this purpose. Since he understood computers and I understood electronics the possibilities of fruitful collaboration were obvious. I remember Newman giving us a few lectures in which he outlined the organisation of a computer in terms of numbers being identified by the address of the house in which they were placed and in terms of numbers being transferred from this address, one at a time, to an accumulator where each entering number was added to what was already there. At any time the number in the accumulator could be transferred back to an assigned address in the store and the accumulator cleared for further use. The transfers were to be effected by a stored program in which a list of instructions was obeyed sequentially. Ordered progress through the list could be interrupted by a test instruction which examined the sign of the number in the accumulator. Thereafter operation started from a new point in the list of instructions. This was the first information I received about the organisation of computers. … Our first computer was the simplest embodiment of these principles, with the sole difference that it used a subtracting rather than an adding accumulator. (Letter from Williams to Randell, 1972; in Randell [1972], p. 9)

Turing's early input to the developments at Manchester, hinted at by Williams in his above-quoted reference to Turing, may have been via the lectures on computer design that Turing and Wilkinson gave in London during the period December 1946 to February 1947 (Turing and Wilkinson [1946–7]). The lectures were attended by representatives of various organisations planning to use or build an electronic computer. Kilburn was in the audience (Bowker and Giordano [1993]). (Kilburn usually said, when asked from where he obtained his basic knowledge of the computer, that he could not remember (letter from Brian Napper to Copeland, 2002); for example, in a 1992 interview he said: ‘Between early 1945 and early 1947, in that period, somehow or other I knew what a digital computer was … Where I got this knowledge from I've no idea’ (Bowker and Giordano [1993], p. 19).)

Whatever role Turing's lectures may have played in informing Kilburn, there is little doubt that credit for the Manchester computer — called the ‘Newman-Williams machine’ in a contemporary document (Huskey 1947) — belongs not only to Williams and Kilburn but also to Newman, and that the influence on Newman of Turing's 1936 paper was crucial, as was the influence of Flowers' Colossus.

The first working AI program, a draughts (checkers) player written by Christopher Strachey, ran on the Ferranti Mark I in the Manchester Computing Machine Laboratory. Strachey (at the time a teacher at Harrow School and an amateur programmer) wrote the program with Turing's encouragement and utilising the latter's recently completed Programmers' Handbook for the Ferranti. (Strachey later became Director of the Programming Research Group at Oxford University.) By the summer of 1952, the program could, Strachey reported, ‘play a complete game of draughts at a reasonable speed’. (Strachey's program formed the basis for Arthur Samuel's well-known checkers program.) The first chess-playing program, also, was written for the Manchester Ferranti, by Dietrich Prinz; the program first ran in November 1951. Designed for solving simple problems of the mate-in-two variety, the program would examine every possible move until a solution was found. Turing started to program his ‘Turochamp’ chess-player on the Ferranti Mark I, but never completed the task. Unlike Prinz's program, the Turochamp could play a complete game (when hand-simulated) and operated not by exhaustive search but under the guidance of heuristics.

Turing's Automatic Computing Engine

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Turing and Newman were thinking along similar lines. In 1945 Turing joined the National Physical Laboratory (NPL) in London, his brief to design and develop an electronic stored-program digital computer for scientific work. (Artificial Intelligence was not far from Turing's thoughts: he described himself as ‘building a brain’ and remarked in a letter that he was ‘more interested in the possibility of producing models of the action of the brain than in the practical applications to computing’.) John Womersley, Turing's immediate superior at NPL, christened Turing's proposed machine the Automatic Computing Engine, or ACE, in homage to Babbage's Difference Engine and Analytical Engine.

Turing's 1945 report ‘Proposed Electronic Calculator’ gave the first relatively complete specification of an electronic stored-program general-purpose digital computer. The report is reprinted in full in Copeland 2005.

The first electronic stored-program digital computer to be proposed in the U.S. was the EDVAC (see below). The ‘First Draft of a Report on the EDVAC’ (May 1945), composed by von Neumann, contained little engineering detail, in particular concerning electronic hardware (owing to restrictions in the U.S.). Turing's ‘Proposed Electronic Calculator’, on the other hand, supplied detailed circuit designs and specifications of hardware units, specimen programs in machine code, and even an estimate of the cost of building the machine (£11,200). ACE and EDVAC differed fundamentally from one another; for example, ACE employed distributed processing, while EDVAC had a centralised structure.

Turing saw that speed and memory were the keys to computing. Turing's colleague at NPL, Jim Wilkinson, observed that Turing ‘was obsessed with the idea of speed on the machine’ [Copeland 2005, p. 2]. Turing's design had much in common with today's RISC architectures and it called for a high-speed memory of roughly the same capacity as an early Macintosh computer (enormous by the standards of his day). Had Turing's ACE been built as planned it would have been in a different league from the other early computers. However, progress on Turing's Automatic Computing Engine ran slowly, due to organisational difficulties at NPL, and in 1948 a ‘very fed up’ Turing (Robin Gandy's description, in interview with Copeland, 1995) left NPL for Newman's Computing Machine Laboratory at Manchester University. It was not until May 1950 that a small pilot model of the Automatic Computing Engine, built by Wilkinson, Edward Newman, Mike Woodger, and others, first executed a program. With an operating speed of 1 MHz, the Pilot Model ACE was for some time the fastest computer in the world.

Sales of DEUCE, the production version of the Pilot Model ACE, were buoyant — confounding the suggestion, made in 1946 by the Director of the NPL, Sir Charles Darwin, that ‘it is very possible that … one machine would suffice to solve all the problems that are demanded of it from the whole country’ [Copeland 2005, p. 4]. The fundamentals of Turing's ACE design were employed by Harry Huskey (at Wayne State University, Detroit) in the Bendix G15 computer (Huskey in interview with Copeland, 1998). The G15 was arguably the first personal computer; over 400 were sold worldwide. DEUCE and the G15 remained in use until about 1970. Another computer deriving from Turing's ACE design, the MOSAIC, played a role in Britain's air defences during the Cold War period; other derivatives include the Packard-Bell PB250 (1961). (More information about these early computers is given in [Copeland 2005].)

Colossus

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The first fully functioning electronic digital computer was Colossus, used by the Bletchley Park cryptanalysts from February 1944.

From very early in the war the Government Code and Cypher School (GC&CS) was successfully deciphering German radio communications encoded by means of the Enigma system, and by early 1942 about 39,000 intercepted messages were being decoded each month, thanks to electromechanical machines known as ‘bombes’. These were designed by Turing and Gordon Welchman (building on earlier work by Polish cryptanalysts).

During the second half of 1941, messages encoded by means of a totally different method began to be intercepted. This new cipher machine, code-named ‘Tunny’ by Bletchley Park, was broken in April 1942 and current traffic was read for the first time in July of that year. Based on binary teleprinter code, Tunny was used in preference to Morse-based Enigma for the encryption of high-level signals, for example messages from Hitler and members of the German High Command.

The need to decipher this vital intelligence as rapidly as possible led Max Newman to propose in November 1942 (shortly after his recruitment to GC&CS from Cambridge University) that key parts of the decryption process be automated, by means of high-speed electronic counting devices. The first machine designed and built to Newman's specification, known as the Heath Robinson, was relay-based with electronic circuits for counting. (The electronic counters were designed by C.E. Wynn-Williams, who had been using thyratron tubes in counting circuits at the Cavendish Laboratory, Cambridge, since 1932 [Wynn-Williams 1932].) Installed in June 1943, Heath Robinson was unreliable and slow, and its high-speed paper tapes were continually breaking, but it proved the worth of Newman's idea. Flowers recommended that an all-electronic machine be built instead, but he received no official encouragement from GC&CS. Working independently at the Post Office Research Station at Dollis Hill, Flowers quietly got on with constructing the world's first large-scale programmable electronic digital computer. Colossus I was delivered to Bletchley Park in January 1943.

By the end of the war there were ten Colossi working round the clock at Bletchley Park. From a cryptanalytic viewpoint, a major difference between the prototype Colossus I and the later machines was the addition of the so-called Special Attachment, following a key discovery by cryptanalysts Donald Michie and Jack Good. This broadened the function of Colossus from ‘wheel setting’ — i.e., determining the settings of the encoding wheels of the Tunny machine for a particular message, given the ‘patterns’ of the wheels — to ‘wheel breaking’, i.e., determining the wheel patterns themselves. The wheel patterns were eventually changed daily by the Germans on each of the numerous links between the German Army High Command and Army Group commanders in the field. By 1945 there were as many 30 links in total. About ten of these were broken and read regularly.

Colossus I contained approximately 1600 vacuum tubes and each of the subsequent machines approximately 2400 vacuum tubes. Like the smaller ABC, Colossus lacked two important features of modern computers. First, it had no internally stored programs. To set it up for a new task, the operator had to alter the machine's physical wiring, using plugs and switches. Second, Colossus was not a general-purpose machine, being designed for a specific cryptanalytic task involving counting and Boolean operations.

F.H. Hinsley, official historian of GC&CS, has estimated that the war in Europe was shortened by at least two years as a result of the signals intelligence operation carried out at Bletchley Park, in which Colossus played a major role. Most of the Colossi were destroyed once hostilities ceased. Some of the electronic panels ended up at Newman's Computing Machine Laboratory in Manchester (see below), all trace of their original use having been removed. Two Colossi were retained by GC&CS (renamed GCHQ following the end of the war). The last Colossus is believed to have stopped running in 1960.

Those who knew of Colossus were prohibited by the Official Secrets Act from sharing their knowledge. Until the 1970s, few had any idea that electronic computation had been used successfully during the second world war. In 1970 and 1975, respectively, Good and Michie published notes giving the barest outlines of Colossus. By 1983, Flowers had received clearance from the British Government to publish a partial account of the hardware of Colossus I. Details of the later machines and of the Special Attachment, the uses to which the Colossi were put, and the cryptanalytic algorithms that they ran, have only recently been declassified. (For the full account of Colossus and the attack on Tunny see Copeland 2006.)

To those acquainted with the universal Turing machine of 1936, and the associated stored-program concept, Flowers' racks of digital electronic equipment were proof of the feasibility of using large numbers of vacuum tubes to implement a high-speed general-purpose stored-program computer. The war over, Newman lost no time in establishing the Royal Society Computing Machine Laboratory at Manchester University for precisely that purpose. A few months after his arrival at Manchester, Newman wrote as follows to the Princeton mathematician John von Neumann (February 1946):

I am … hoping to embark on a computing machine section here, having got very interested in electronic devices of this kind during the last two or three years. By about eighteen months ago I had decided to try my hand at starting up a machine unit when I got out. … I am of course in close touch with Turing.

Atanasoff

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The earliest comparable use of vacuum tubes in the U.S. seems to have been by John Atanasoff at what was then Iowa State College (now University). During the period 1937–1942 Atanasoff developed techniques for using vacuum tubes to perform numerical calculations digitally. In 1939, with the assistance of his student Clifford Berry, Atanasoff began building what is sometimes called the Atanasoff-Berry Computer, or ABC, a small-scale special-purpose electronic digital machine for the solution of systems of linear algebraic equations. The machine contained approximately 300 vacuum tubes. Although the electronic part of the machine functioned successfully, the computer as a whole never worked reliably, errors being introduced by the unsatisfactory binary card-reader. Work was discontinued in 1942 when Atanasoff left Iowa State.

Electromechanical versus Electronic Computation

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With some exceptions — including Babbage's purely mechanical engines, and the finger-powered National Accounting Machine - early digital computing machines were electromechanical. That is to say, their basic components were small, electrically-driven, mechanical switches called ‘relays’. These operate relatively slowly, whereas the basic components of an electronic computer — originally vacuum tubes (valves) — have no moving parts save electrons and so operate extremely fast. Electromechanical digital computing machines were built before and during the second world war by (among others) Howard Aiken at Harvard University, George Stibitz at Bell Telephone Laboratories, Turing at Princeton University and Bletchley Park, and Konrad Zuse in Berlin. To Zuse belongs the honour of having built the first working general-purpose program-controlled digital computer. This machine, later called the Z3, was functioning in 1941. (A program-controlled computer, as opposed to a stored-program computer, is set up for a new task by re-routing wires, by means of plugs etc.)

Relays were too slow and unreliable a medium for large-scale general-purpose digital computation (although Aiken made a valiant effort). It was the development of high-speed digital techniques using vacuum tubes that made the modern computer possible.

The earliest extensive use of vacuum tubes for digital data-processing appears to have been by the engineer Thomas Flowers, working in London at the British Post Office Research Station at Dollis Hill. Electronic equipment designed by Flowers in 1934, for controlling the connections between telephone exchanges, went into operation in 1939, and involved between three and four thousand vacuum tubes running continuously. In 1938–1939 Flowers worked on an experimental electronic digital data-processing system, involving a high-speed data store. Flowers' aim, achieved after the war, was that electronic equipment should replace existing, less reliable, systems built from relays and used in telephone exchanges. Flowers did not investigate the idea of using electronic equipment for numerical calculation, but has remarked that at the outbreak of war with Germany in 1939 he was possibly the only person in Britain who realized that vacuum tubes could be used on a large scale for high-speed digital computation. (See Copeland 2006 for m more information on Flowers' work.)

The Universal Turing Machine

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In 1936, at Cambridge University, Turing invented the principle of the modern computer. He described an abstract digital computing machine consisting of a limitless memory and a scanner that moves back and forth through the memory, symbol by symbol, reading what it finds and writing further symbols (Turing [1936]). The actions of the scanner are dictated by a program of instructions that is stored in the memory in the form of symbols. This is Turing's stored-program concept, and implicit in it is the possibility of the machine operating on and modifying its own program. (In London in 1947, in the course of what was, so far as is known, the earliest public lecture to mention computer intelligence, Turing said, ‘What we want is a machine that can learn from experience’, adding that the ‘possibility of letting the machine alter its own instructions provides the mechanism for this’ (Turing [1947] p. 393). Turing's computing machine of 1936 is now known simply as the universal Turing machine. Cambridge mathematician Max Newman remarked that right from the start Turing was interested in the possibility of actually building a computing machine of the sort that he had described (Newman in interview with Christopher Evans in Evans [197?].

From the start of the Second World War Turing was a leading cryptanalyst at the Government Code and Cypher School, Bletchley Park. Here he became familiar with Thomas Flowers' work involving large-scale high-speed electronic switching (described below). However, Turing could not turn to the project of building an electronic stored-program computing machine until the cessation of hostilities in Europe in 1945.

During the wartime years Turing did give considerable thought to the question of machine intelligence. Colleagues at Bletchley Park recall numerous off-duty discussions with him on the topic, and at one point Turing circulated a typewritten report (now lost) setting out some of his ideas. One of these colleagues, Donald Michie (who later founded the Department of Machine Intelligence and Perception at the University of Edinburgh), remembers Turing talking often about the possibility of computing machines (1) learning from experience and (2) solving problems by means of searching through the space of possible solutions, guided by rule-of-thumb principles (Michie in interview with Copeland, 1995). The modern term for the latter idea is ‘heuristic search’, a heuristic being any rule-of-thumb principle that cuts down the amount of searching required in order to find a solution to a problem. At Bletchley Park Turing illustrated his ideas on machine intelligence by reference to chess. Michie recalls Turing experimenting with heuristics that later became common in chess programming (in particular minimax and best-first).

Further information about Turing and the computer, including his wartime work on codebreaking and his thinking about artificial intelligence and artificial life, can be found in Copeland 2004.

Analog computers

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The earliest computing machines in wide use were not digital but analog. In analog representation, properties of the representational medium ape (or reflect or model) properties of the represented state-of-affairs. (In obvious contrast, the strings of binary digits employed in digital representation do not represent by means of possessing some physical property — such as length — whose magnitude varies in proportion to the magnitude of the property that is being represented.) Analog representations form a diverse class. Some examples: the longer a line on a road map, the longer the road that the line represents; the greater the number of clear plastic squares in an architect's model, the greater the number of windows in the building represented; the higher the pitch of an acoustic depth meter, the shallower the water. In analog computers, numerical quantities are represented by, for example, the angle of rotation of a shaft or a difference in electrical potential. Thus the output voltage of the machine at a time might represent the momentary speed of the object being modelled.

As the case of the architect's model makes plain, analog representation may be discrete in nature (there is no such thing as a fractional number of windows). Among computer scientists, the term ‘analog’ is sometimes used narrowly, to indicate representation of one continuously-valued quantity by another (e.g., speed by voltage). As Brian Cantwell Smith has remarked:

‘Analog’ should … be a predicate on a representation whose structure corresponds to that of which it represents … That continuous representations should historically have come to be called analog presumably betrays the recognition that, at the levels at which it matters to us, the world is more foundationally continuous than it is discrete. (Smith [1991], p. 271)

James Thomson, brother of Lord Kelvin, invented the mechanical wheel-and-disc integrator that became the foundation of analog computation (Thomson [1876]). The two brothers constructed a device for computing the integral of the product of two given functions, and Kelvin described (although did not construct) general-purpose analog machines for integrating linear differential equations of any order and for solving simultaneous linear equations. Kelvin's most successful analog computer was his tide predicting machine, which remained in use at the port of Liverpool until the 1960s. Mechanical analog devices based on the wheel-and-disc integrator were in use during World War I for gunnery calculations. Following the war, the design of the integrator was considerably improved by Hannibal Ford (Ford [1919]).

Stanley Fifer reports that the first semi-automatic mechanical analog computer was built in England by the Manchester firm of Metropolitan Vickers prior to 1930 (Fifer [1961], p. 29); however, I have so far been unable to verify this claim. In 1931, Vannevar Bush, working at MIT, built the differential analyser, the first large-scale automatic general-purpose mechanical analog computer. Bush's design was based on the wheel and disc integrator. Soon copies of his machine were in use around the world (including, at Cambridge and Manchester Universities in England, differential analysers built out of kit-set Meccano, the once popular engineering toy).

It required a skilled mechanic equipped with a lead hammer to set up Bush's mechanical differential analyser for each new job. Subsequently, Bush and his colleagues replaced the wheel-and-disc integrators and other mechanical components by electromechanical, and finally by electronic, devices.

A differential analyser may be conceptualised as a collection of ‘black boxes’ connected together in such a way as to allow considerable feedback. Each box performs a fundamental process, for example addition, multiplication of a variable by a constant, and integration. In setting up the machine for a given task, boxes are connected together so that the desired set of fundamental processes is executed. In the case of electrical machines, this was done typically by plugging wires into sockets on a patch panel (computing machines whose function is determined in this way are referred to as ‘program-controlled’).

Since all the boxes work in parallel, an electronic differential analyser solves sets of equations very quickly. Against this has to be set the cost of massaging the problem to be solved into the form demanded by the analog machine, and of setting up the hardware to perform the desired computation. A major drawback of analog computation is the higher cost, relative to digital machines, of an increase in precision. During the 1960s and 1970s, there was considerable interest in ‘hybrid’ machines, where an analog section is controlled by and programmed via a digital section. However, such machines are now a rarity.

Babbage

2009-07-05T00:02:00.000-07:00

Charles Babbage was Lucasian Professor of Mathematics at Cambridge University from 1828 to 1839 (a post formerly held by Isaac Newton). Babbage's proposed Difference Engine was a special-purpose digital computing machine for the automatic production of mathematical tables (such as logarithm tables, tide tables, and astronomical tables). The Difference Engine consisted entirely of mechanical components — brass gear wheels, rods, ratchets, pinions, etc. Numbers were represented in the decimal system by the positions of 10-toothed metal wheels mounted in columns. Babbage exhibited a small working model in 1822. He never completed the full-scale machine that he had designed but did complete several fragments. The largest — one ninth of the complete calculator — is on display in the London Science Museum. Baabage used it to perform serious computational work, calculating various mathematical tables. In 1990, Babbage's Difference Engine No. 2 was finally built from Babbage's designs and is also on display at the London Science Museum.

The Swedes Georg and Edvard Scheutz (father and son) constructed a modified version of Babbage's Difference Engine. Three were made, a prototype and two commercial models, one of these being sold to an observatory in Albany, New York, and the other to the Registrar-General's office in London, where it calculated and printed actuarial tables.

Babbage's proposed Analytical Engine, considerably more ambitious than the Difference Engine, was to have been a general-purpose mechanical digital computer. The Analytical Engine was to have had a memory store and a central processing unit (or ‘mill’) and would have been able to select from among alternative actions consequent upon the outcome of its previous actions (a facility nowadays known as conditional branching). The behaviour of the Analytical Engine would have been controlled by a program of instructions contained on punched cards connected together with ribbons (an idea that Babbage had adopted from the Jacquard weaving loom). Babbage emphasised the generality of the Analytical Engine, saying ‘the conditions which enable a finite machine to make calculations of unlimited extent are fulfilled in the Analytical Engine’ (Babbage [1994], p. 97).

Babbage worked closely with Ada Lovelace, daughter of the poet Byron, after whom the modern programming language ADA is named. Lovelace foresaw the possibility of using the Analytical Engine for non-numeric computation, suggesting that the Engine might even be capable of composing elaborate pieces of music.

A large model of the Analytical Engine was under construction at the time of Babbage's death in 1871 but a full-scale version was never built. Babbage's idea of a general-purpose calculating engine was never forgotten, especially at Cambridge, and was on occasion a lively topic of mealtime discussion at the war-time headquarters of the Government Code and Cypher School, Bletchley Park, Buckinghamshire, birthplace of the electronic digital computer.

The Colossus

2009-07-04T20:41:00.001-07:00

This meant that a machine would be needed to exploit the weaknesses found. To solve this problem Tommy Flowers, an engineer who worked for the post office, designed a machine which worked on the digital data stream of the Lorenz traffic and could carry out the statistical tests needed to find the key. One of the things he needed to take into account when designing the machine though was that different tests might be needed to be used at different times. As a result he designed the machine in a flexible way so that it could carry out whatever tests ended up being needed.

So Colossus was able to process digital data. It was also able to perform different tasks, including ones that were not envisaged by its designers. Even better you could use Colossus to perform other calculations that were not necessarily related to code breaking. That's a feature which distinguishes it from the Bombes, and a feature which makes its claim as the first modern computer.

In short, Colossus was a programmable digital computer just as modern computers are. One distinct difference between Colossus and modern computers though is that Colossus was programmed by someone connecting various pieces of the machine together using wires. A modern computer's program is stored with its data, inside the machine. This improvement did not come until a machine called the Manchester Baby in 1948.

Who Built The First Modern Computer?

2009-07-04T20:38:00.002-07:00

Most people think it was an American team that built the first working computer. In fact, the world's first programmable digital computer was built in secret by the British in the Second World War at Bletchley Park. Bletchley is famous as the place where the Enigma cipher machine was broken: a task which they performed efficiently using a machine called a Bombe. However, the most important thing that Bletchley did was neither breaking the Enigma code nor creating the Bombes. Professor Nigel Smart, Head of the Department of Computer Science at the University of Bristol and an expert on cryptography tells us more.

Enigma and Lorenz

The Enigma machine was used by the Germans to encrypt low level secret communications, such as battlefield communications or communications to U-Boats. It was a mechanical device which operated on letters. An operator encrypted a message using a typewriter like interface and then the encoded message was sent using Morse Code.

The Lorenz machine was the machine used by the Germans for more strategic communication. It took as input a message encoded using what is called a Baudot code. Baudot code had been used for years for teleprinter communications, and is essentially a conversion of the message into binary (a "binary encoding"): 1s and 0s. The Lorenz cipher would then encrypt the message to produce another binary encoding of the message (but now a binary encoding of the encrypted message).

Since the Lorenz cipher worked on binary encodings it could process information much faster than the Enigma machine, since no one needed to type a message into the machine. The Lorenz cipher was used by Hitler to communicate between his centres of command. If the Allies could break into the Lorenz information they would know what Hitler and his followers were actually thinking.

A Toe In The Door

In breaking the Enigma machine the British had the advantage of actually having an Enigma machine which had been recovered by the Polish. When breaking into the Lorenz machine though, they did not have a clue how it worked at all. To make it worse still, picking up the airborn traffic was harder. Intercepting the remote binary signal produced by Lorenz machines was much more difficult than recognizing the Morse code used by the Enigma.

They worked out exactly how the Lorenz machine worked just from seeing scrambled messages

However, by setting up listening stations the British recovered enough messages for the British cryptographers at Bletchley to actually work out exactly how the Lorenz machine worked, without ever seeing one. It was an amazing intellectual feat.

The cryptographers at Bletchley also worked out how to break the machine using subtle statistical weaknesses of the machine. Unfortunately, to actually exploit the weaknesses they needed to process a large amount of data. A lot of calculations would need to be performed on a given target message quickly. After all cracking a message years after it was sent wasn't a lot of help.

An Example of the Computer Modern Roman Font

2009-07-04T20:38:00.001-07:00

Below is an example of the Computer Modern Roman text font and the Computer Modern Math Italic font. Please note that considerable image quality has been lost converting this example from PostScript into GIF format. Actual Textures output will be much sharper and cleaner. If you would like to see the same example typeset in a different font, click the appropriate option.

Modern computer technology benefits North Cotabato mentors

2009-07-04T20:37:00.001-07:00

MIDSAYAP, North Cotabato – More than a hundred teachers from four public elementary school districts in this town are now using modern computer technology to compose their lesson plans, create better and richer teaching materials, and compute their students’ grades.

This is the result of the recent turnover to their Department of Education (DepEd) districts of 32 computers installed with Microsoft Office, Encarta, and anti-virus software and 18 printers by the United States Agency for International Development (USAID) through its Education Quality and Access for Learning and Livelihood Skills (EQuALLS2) Project.

The turnover of the computer equipment and software came less than a month after the project trained the teachers to use the software through a partnership with Microsoft Philippines, in support of DepEd’s strategic plan for ICT-enhanced professional development activities for teachers and school officials.

The teachers eagerly attended the five-day training, arriving early and refusing to go home at the end of the day.

They asked that more training be given to them on other software relevant to teaching, documentation, and data gathering.

“It’s never too late to learn computer skills, and it’s a source of excitement and challenge whenever we discover new teaching strategies through the use of computers,” said Elmer Castro, principal of the Kimagango Elementary School, one of the schools that received the computers and participated in the training.

The trained teachers will practice using the computers for the next three to six months, after which, each of them will train one to two other teachers.

USAID’s EQuALLS2 project, through its implementing partner, Save the Children, will check on the teachers’ progress quarterly.

The computers will be maintained by their respective DepEd district offices, which are expected to institute policies that will require local teachers to submit lesson plans in electronic form.

While nine other municipalities in Mindanao will also receive the same computer training and equipment from the project.

USAID’s EQuALLS2 Project aims to improve education in Mindanao by strengthening capacity for teaching English, math, and science at the elementary level, increasing learning opportunities for children and youth through cultivation of community support for education, and extending productivity training to out-of-school children and youth. (EQuALLS2)

Ada Lovelace - The Enchantress of Number or the most Overrated Figure in the History of Computing?

2009-07-04T20:34:00.001-07:00

Augusta Ada, Countess of Lovelace (1815 to 1852), also known as Ada Lovelace, was the only legitimate daughter of the poet Lord Byron. Raised by her mother she was given private instruction in mathematics and sciences, When she was 17 she met Charles Babbage at a party and became interested in his work on The Analytical Engine, At the suggestion of Charles Wheatstone she translated a French description of the Analytical Engine "Notions sur la machine analytique" by the Italian Engineer Luigi Menabrea. This document was based on some lectures Babbage had delivered in Turin some years earlier. After reading Ada's translation Babbage suggested she add some notes of her own since she was "intimately acquainted" with the subject. This she did and published her Sketch of the Analytical Engine in 1843.

The Meaning of Invention

2009-07-04T20:33:00.002-07:00

I 've been trying to understand what it means to invent something and found this site very useful Wright Brothers History: The Tale of the Airplane A Brief Account of the Invention of the Airplane researched, written, and designed by Gary Bradshaw.

This graph really sums it up. You don't have to be first but you do have to change the Paradigm.

The Figure above depicts the longest flights made by various aircraft in the period 1890 to 1909. Green points represent the various Wright craft during this period. Blue points represent non-Wright craft made between 1890 and 1905, while red points represent non-Wright craft made from 1906 to 1909. Lines on the graph are regression functions. The flat blue line indicates that the field as a whole was making NO sustained progress through the end of 1905. This lack of progress is almost invariably true of individual inventors as well as the group as a whole. The positive slope of the Wright brothers indicates a steady progression in the ability of their heavier-than-air craft. Once details of the Wrights methods became public when their patent was issued in late 1905, other inventors quickly copied the important discoveries of the Wright brothers, and developed airplanes as capable as those of the Wrights.

The First Modern Computer - The Case for Baby, the Manchester Mk I Prototype

2009-07-04T20:33:00.001-07:00

Finding an authoritative history of the Computer's invention is almost impossible. There are several reasons for this problem: People disagree on the meaning of the word "invent", they also disagree on the meaning of the word "computer". Finally significant parts of the history were either lost or deliberately concealed and only came to light again in the 1960's and 70's. The United States Army was the first organization to stake a claim to the invention of the computer with the 1946 public announcement of the ENIAC (Electronic Numerical Integrator and Computer). It has since become commonly accepted that ENIAC was the worlds first computer when in fact it was not a computer, in the modern sense, at all, and was not even the first of its class.

The Art of Turing Completion

2009-07-04T20:32:00.003-07:00

As I was researching the invention of the computer I found a few sites that while only tangentially related to the subject at hand were definitely worthy of note.

The First Railway Station: Unlikely Home for the First Computer

2009-07-04T20:32:00.001-07:00

The Liverpool Street Station in Manchester, England is now part of The museum of Science and Technology. The Station was built in 1830 and is the oldest railway station in the world. On the opposite side of the tracks to the ticketing hall is the world's first railway warehouse. In this building is a working replica of the worlds first stored program computer, Baby, the Manchester Mk I Prototype.

Misinformation and the Evolution of Early Computers

2009-07-04T20:31:00.001-07:00

Amazing and totally inaccurate!

Click on the image to get a legible version

It's difficult to know where to start in cataloging the faults with this diagram. So rather than waste my time trying I've started collating information to produce a better version. I'll publish it here when I'm done.

I'm not sure where this diagram came from. It could be "Computer Structures" by Gordon Bell. But the reference was unclear.

The Moore School Lectures and the British Lead in Stored Program Computer Development (1946 -1953)

2009-07-04T20:30:00.000-07:00

In 1946 between 8th July and 31st August the Moore School of Electrical Engineering at the University of Pennsylvania held a special course entitled Theory and Techniques for Design of Electronic Digital Computers. The course was organized in response to interest generated by; the schools public announcement of the ENIAC, and the publication of The First Draft of a Report on the EDVAC. 1945 by Jon von Neumann. Attendance was by invitation only and the "Students" were selected from the leading experts at the major institutions working on the development of computing devices in the US and UK. At the time of this event there were only three published designs for a stored program computer and it was expected that all those present were familiar with these documents.

The First Draft of a Report on the EDVAC. by Jon von Neumann. 1945
Proposed Electronic Calculator.by Alan Turing. 1945.
Preliminary report on the proposal for an IAS machine by A.W. Burks, H.H. Goldstine and John von Neumann. June 1946

Within two years of these lectures the first stored program computer was operational, within 3 years there were 5 operational machines, and within 5 years stored program machines were commercially available. The Moore School Lectures, as they became known, were responsible for focusing all the leading developers of computing devices on a single problem:- How to design and build a stored program computer. It is interesting that despite being outnumbered and out-funded the British took, and held, the lead in this development effort between 1946 and 1953. In some areas such as business applications the British held the lead for much longer. How they were able to do this is not directly explained in any of the historical material available online, which tends to focus on individual development efforts and not on the larger picture.

The Evolution of the Modern Computer (1934 to 1950): An Open Source Graphical History

2009-07-04T20:29:00.002-07:00

Some time between 1934 and 1950 the first modern computer was created. Pinning down exactly when that event occured is not easy. It depends on how you define the term computer and what you think is more important: The concept, the design, the first succesful test, or the first time the machine solved a real problem. In those early days it usually took years for a team to progress from concept through design to working machine. There were many such teams working mainly in the US and UK. These teams competed and cooperated somtimes they shared ideas and designs, and they sent representatives to visit each others laboratories. On one famous occassion in the Summer of 1946 almost all the leaders in the field got together at the Moore School for an 8 week long series of lectures. In short the story of the emergence of the modern computer is a complex one that involves both direct and indirect contributions from many people.

There are many Computer History Timelines in existence. But all of these suffer from the same flaws. They are incomplete and thier linear nature fails to capture the complex web of influence that was the hallmark of computer development.

Downloadable files available here

In an effort to visualize this web of interaction. I have started to develop a graphical representation of the evolution of the modern computer. Fortunately AT&T have kindly released a package called Graphviz which is capable of drawing complex directed graphs. The graph above is produced by Graphviz from a text file.

The text file contains a detailed description of my approach, the classification I have used, and lists all the machines and the references to the data sources I used. I have not duplicated that information here because the whole point of the exercise is to gather all the data in one place.

I have licensed this file with an attribution, share alike creative commons license. So please feel free to download and improve what I have started. If you do make changes please send me a copy and I will share the updates on this page.

For the record. I believe that The Manchester Mk I Prototype was the first Computer in a modern sense. But the text file is not intended to prove this or any other machine was first. It is only intended to record the known dates and influences for computing machines designed between 1934 and 1950. I Believe that the graph is complex enough to support many interpretations.

Vannevar Bush and The Limits of Prescience

2009-07-04T20:29:00.001-07:00

Today Vannevar Bush (rhymes with achiever) is often remembered for his July 1945 Atlantic Monthly article As We May Think in which he describes a hypothetical machine called a Memex. This machine contained a large indexed store of information and allowed a user to navigate through the store using a system similar to hypertext links. At the time of writing his essay Bush knew more about the state of technology development in the US than almost any other person. During the war, he was Roosevelt's chief adviser on military research. He was responsible for many war time research projects including Radar, the Atomic Bomb, and the development of early Computers. If anyone should ever have been capable of predicting the future it was Vannevar Bush in 1945. He is an almost unprecedented test case for the art of prediction. Unlike almost anyone else before or since Bush was actually in possession of ALL the facts - as only the head of technology research in a country at war could be.

Charles Babbage and Howard Aiken. How the Analytical Engine influenced the IBM Automatic Sequence Controlled Calculator aka The Harvard Mk I

2009-07-04T20:28:00.001-07:00

In 1936, [Howard] Aiken had proposed his idea [to build a giant calculating machine] to the [Harvard University] Physics Department, ... He was told by the chairman, Frederick Saunders, that a lab technician, Carmelo Lanza, had told him about a similar contraption already stored up in the Science Center attic.

Intrigued, Aiken had Lanza lead him to the machine, which turned out to be a set of brass wheels from English mathematician and philosopher Charles Babbage's unfinished "analytical engine" from nearly 100 years earlier.

Aiken immediately recognized that he and Babbage had the same mechanism in mind. Fortunately for Aiken, where lack of money and poor materials had left Babbage's dream incomplete, he would have much more success.

Later, those brass wheels, along with a set of books that had been given to him by the grandson of Babbage, would occupy a prominent spot in Aiken's office. In an interview with I. Bernard Cohen '37, PhD '47, Victor S. Thomas Professor of the History of Science Emeritus, Aiken pointed to Babbage's books and said, "There's my education in computers, right there; this is the whole thing, everything I took out of a book."

[The Harvard University Gazette. Howard Aiken: Makin' a Computer Wonder By Cassie Furguson]

History of Computer

2009-07-04T20:24:00.000-07:00

"Who invented the computer?" is not a question with a simple answer. The real answer is that many inventors contributed to the history of computers and that a computer is a complex piece of machinery made up of many parts, each of which can be considered a separate invention.

This series covers many of the major milestones in computer history (but not all of them) with a concentration on the history of personal home computers.

Computer History Year/Enter	Computer History Inventors/Inventions	Computer History Description of Event
1936	Konrad Zuse - Z1 Computer	First freely programmable computer.
1942	John Atanasoff & Clifford Berry ABC Computer	Who was first in the computing biz is not always as easy as ABC.
1944	Howard Aiken & Grace Hopper Harvard Mark I Computer	The Harvard Mark 1 computer.
1946	John Presper Eckert & John W. Mauchly ENIAC 1 Computer	20,000 vacuum tubes later...
1948	Frederic Williams & Tom Kilburn Manchester Baby Computer & The Williams Tube	Baby and the Williams Tube turn on the memories.
1947/48	John Bardeen, Walter Brattain & Wiliam Shockley The Transistor	No, a transistor is not a computer, but this invention greatly affected the history of computers.
1951	John Presper Eckert & John W. Mauchly UNIVAC Computer	First commercial computer & able to pick presidential winners.
1953	International Business Machines IBM 701 EDPM Computer	IBM enters into 'The History of Computers'.
1954	John Backus & IBM FORTRAN Computer Programming Language	The first successful high level programming language.
1955 (In Use 1959)	Stanford Research Institute, Bank of America, and General Electric ERMA and MICR	The first bank industry computer - also MICR (magnetic ink character recognition) for reading checks.
1958	Jack Kilby & Robert Noyce The Integrated Circuit	Otherwise known as 'The Chip'
1962	Steve Russell & MIT Spacewar Computer Game	The first computer game invented.
1964	Douglas Engelbart Computer Mouse & Windows	Nicknamed the mouse because the tail came out the end.
1969	ARPAnet	The original Internet.
1970	Intel 1103 Computer Memory	The world's first available dynamic RAM chip.
1971	Faggin, Hoff & Mazor Intel 4004 Computer Microprocessor	The first microprocessor.
1971	Alan Shugart &IBM The "Floppy" Disk	Nicknamed the "Floppy" for its flexibility.
1973	Robert Metcalfe & Xerox The Ethernet Computer Networking	Networking.
1974/75	Scelbi & Mark-8 Altair & IBM 5100 Computers	The first consumer computers.
1976/77	Apple I, II & TRS-80 & Commodore Pet Computers	More first consumer computers.
1978	Dan Bricklin & Bob Frankston VisiCalc Spreadsheet Software	Any product that pays for itself in two weeks is a surefire winner.
1979	Seymour Rubenstein & Rob Barnaby WordStar Software	Word Processors.
1981	IBM The IBM PC - Home Computer	From an "Acorn" grows a personal computer revolution
1981	Microsoft MS-DOS Computer Operating System	From "Quick And Dirty" comes the operating system of the century.
1983	Apple Lisa Computer	The first home computer with a GUI, graphical user interface.
1984	Apple Macintosh Computer	The more affordable home computer with a GUI.
1985	Microsoft Windows	Microsoft begins the friendly war with Apple.
SERIES	TO BE	CONTINUED

The Invention of the Intel 1103 - The World's First Available DRAM Chip

2009-07-03T17:16:00.001-07:00

In 1970, the newly formed Intel company publicly released the 1103, the first DRAM (Dynamic Random Access Memory) chip (1K bit PMOS dynamic RAM ICs), and by 1972 it was the best selling semiconductor memory chip in the world, defeating magnetic core type memory. The first commercially available computer using the 1103 was the HP 9800 series.

Dr. Robert H. Dennard, a Fellow at the IBM Thomas J. Watson Research Center created the one-transistor DRAM in 1966. Dennard and his team were working on early field-effect transistors and integrated circuits, and his attention to memory chips came from seeing another team's research with thin-flim magnetic memory. Dennard claims he went home and within a few hours had gotten the basic ideas for the creation of DRAM. He worked on his ideas for a simpler memory cell that used only a single transistor and a small capacitor. IBM and Dennard were granted a patent for DRAM in 1968.

RAM stands for random access memory, memory that can be accessed or written to randomly -- any byte or piece of memory can be used without accessing the other bytes or pieces of memory. There were two basic types of RAM, dynamic RAM (DRAM) and static RAM (SRAM). DRAM needs to be refreshed thousands of times per second. SRAM does not need to be refreshed, which makes it faster. Both types of RAM are volatile -- they lose their contents when the power is turned off. In 1970, Fairchild Corporation invented the first 256-k SRAM chip. Recently, several new types of RAM chips have been designed.

John Reed now head of The Reed Company was once part of the Intel 1103 team. Reed offered the following memories on the development of the Intel 1103.

The "invention?" In those days, Intel, (nor few others for that matter), was not focusing on getting patents or achieving "inventions" so much as they were desperate to get new products to market and begin reaping the profits. But let me tell you how the i1103 was born and raised:

In approximately. 1969, William Regitz of Honeywell canvassed the semiconductor companies of the U.S. looking for someone to share in the development of a dynamic memory circuit based on a novel 3-transistor cell which he (or one of his co-workers) had invented. I won't elaborate, but this cell was a "1X, 2Y" type cell laid out with a "butted" contact for connecting the pass transistor drain to the gate of the cell's current switch.

Regitz talked to many companies, but Intel got really excited about the possibilities here and decided to go ahead with a development program. Moreover, whereas Regitz had originally been proposing a 512-bit chip, Intel decided that 1,024 bits would be feasible, and so the program began. Joel Karp of Intel was the circuit designer, and he worked closely with Regitz throughout the program. It culminated in actual working units, and a paper was given on this device, the i1102, at the 1970 ISSCC conference in Philadelphia.

Intel learned several lessons from the i1102, namely:

DRAM cells needed substrate bias. This spawned the 18 pin DIP package.
The "butting" contact was a tough technological problem to solve, and yields were low.
The "IVG" multi-level cell strobe signal made necessary by the "1X, 2Y" cell circuitry caused the devices to have very small operating margins.

Though they continued to develop the i1102, there was a need to look at other cell techniques. Ted Hoff had proposed all possible ways of wiring up 3 transistors in a DRAM cell earlier, and at this time somebody took a closer look at the "2X, 2Y" cell, I think it may have been Karp and/or Leslie Vadasz. (I hadn't come to Intel yet) The idea of using a "buried contact" was applied (probably by Tom Rowe, process guru), and this cell became more and more attractive, since it could potentially do away with both the butting contact issue and the aforementioned multi-level signal requirement and yield a smaller cell to boot!

So Vadasz and Karp sketched out a schematic of an i1102 alternative (on the sly, since this wasn't exactly a popular decision with Honeywell), and assigned the job of designing the chip to Bob Abbott sometime before I came on the scene in June 1970. He initiated the design and had it laid out. I took over the project after initial "200X" masks had been shot from the original mylar layouts, and it was my job to evolve the product from there which was no small task in itself.

Well, it's hard to make a long story short, but the first silicon chips of the i1103 were practically non-functional, until it was discovered that the overlap between the "PRECH" clock and the "CENABLE" clock, the famous "Tov" parameter, was VERY critical due to our lack of understanding of internal cell dynamics. This was a discovery made by test engineer George Staudacher. Nevertheless, understanding this weakness, I characterized the devices on hand, and we drew up a data sheet. Because of the low yields we were seeing,due to the "Tov" problem, Vadasz and I recommended to Intel management that the product wasn't ready for market, but Bob Graham, then Intel Marketing V.P., thought otherwise and pushed for an early introduction, over our dead bodies so to speak. The Intel i1103 "came to market" in October of 1970.

After the product introduction, demand was strong, and it was my job to evolve the design for better yield. I did this in stages, making improvements at every new mask generation until the "E" revision of the masks, at which point, the i1103 was yielding well and performing well. This early work of mine established a couple of things:

Based on my analysis of 4 runs of devices, the refresh time was set at 2 milliseconds. Binary multiples of that initial characterization are still the standard to this day.
I was probably the first designer to use Si-gate transistors as bootstrap capacitors; my evolving mask sets had several of these to improve performance and margins.

And that's about all I can say about the Intel 1103's "invention." I will say that "getting inventions" was just not a value amongst us circuit designers of those days. I am personally named on 14 memory-related patents, but in those days, I'm sure I invented many more techniques in the course of getting a circuit developed and out to market without stopping to make any disclosures. That Intel itself wasn't concerned about patents until "too late" is evidence, in my own case, by the 4 or 5 patents I was awarded, applied for and assigned to 2 years after I left the company at the end of 1971! (Look at one of them, and you'll see me listed as an Intel employee!) - John Reed

ARPAnet - The First Internet

2009-07-03T17:14:00.000-07:00

"The Internet may fairly be regarded as a never-ending worldwide conversation." - supreme judge statement on considering first amendment rights for Internet users.

On a cold war kind of day, in swinging 1969, work began on the ARPAnet, grandfather to the Internet. Designed as a computer version of the nuclear bomb shelter, ARPAnet protected the flow of information between military installations by creating a network of geographically separated computers that could exchange information via a newly developed protocol (rule for how computers interact) called NCP (Network Control Protocol).

One opposing view to ARPAnet's origins comes from Charles M. Herzfeld, the former director of ARPA. He claimed that ARPAnet was not created as a result of a military need, stating "it came out of our frustration that there were only a limited number of large, powerful research computers in the country and that many research investigators who should have access were geographically separated from them." ARPA stands for the Advanced Research Projects Agency, a branch of the military that developed top secret systems and weapons during the Cold War.

To send a message on the network, a computer breaks its data into IP (Internet Protocol) packets, like individually addressed digital envelopes. TCP (Transmission Control Protocol) makes sure the packets are delivered from client to server and reassembled in the right order.

Under ARPAnet several major innovations occurred: email (or electronic mail), the ability to send simple messages to another person across the network (1971); telnet, a remote connection service for controlling a computer (1972); and file transfer protocol (FTP), which allows information to be sent from one computer to another in bulk (1973).

As non-military uses for the network increased, more and more people had access, and it was no longer safe for military purposes. As a result, MILnet, a military only network, was started in 1983. Internet Protocol software was soon being placed on every type of computer, and universities and research groups also began using in-house networks known as Local Area Networks or LAN's. These in-house networks then started using Internet Protocol software so one LAN could connect with other LAN's.

In 1986, one LAN branched out to form a new competing network, called NSFnet (National Science Foundation Network). NSFnet first linked together the five national supercomputer centers, then every major university, and it started to replace the slower ARPAnet (which was finally shutdown in 1990). NSFnet formed the backbone of what we call the Internet today.

"The Internet's pace of adoption eclipses all other technologies that preceded it. Radio was in existence 38 years before 50 million people tuned in; TV took 13 years to reach that benchmark. Sixteen years after the first PC kit came out, 50 million people were using one. Once it was opened to the general public, the Internet crossed that line in four years." - quote from the U.S. Department report "The Emerging Digital Economy".

The History of the Computer Mouse and the Prototype for Windows - Douglas Engelbart

2009-07-03T17:13:00.000-07:00

In 1964, the first prototype computer mouse was made to use with a graphical user interface (GUI), 'windows'. Engelbart received a patent for the wooden shell with two metal wheels (computer mouse U.S. Patent # 3,541,541) in 1970, describing it in the patent application as an "X-Y position indicator for a display system." "It was nicknamed the mouse because the tail came out the end," Engelbart revealed about his invention. His version of windows was not considered patentable (no software patents were issued at that time), but Douglas Engelbart has over 45 other patents to his name.

Throughout the '60s and '70s, while working at his own lab (Augmentation Research Center, Stanford Research Institute), Engelbart dedicated himself to creating a hypermedia groupware system called NLS (for oNLine System). Most of his accomplishments, including the computer mouse and windows, were part of NLS.

In 1968, a 90-minute, staged public demonstration of a networked computer system was held at the Augmentation Research Center -- the first public appearance of the mouse, windows, hypermedia with object linking and addressing, and video teleconferencing.

Douglas Engelbart was awarded the 1997 Lemelson-MIT Prize of $500,000, the world's largest single prize for invention and innovation. In 1998, he was inducted into the National Inventors Hall of Fame.

Currently, Douglas Engelbart is the director of his company, Bootstrap Institute in Fremont, California, which promotes the concept of Collective IQ. Ironically, Bootstrap is housed rent free courtesy of the Logitech Corp., a famous manufacturer of computer mice.

Spacewar! : The first computer game invented by Steve Russell

2009-07-03T17:12:00.000-07:00

If I hadn't done it, someone would've done something equally exciting if not better in the next six months. I just happened to get there first." - Steve Russell nickname "Slug"

It was in 1962 when a young computer programmer from MIT, Steve Russell fueled with inspiration from the writings of E. E. "Doc" Smith*, led the team that created the first computer game. It took the team about 200 man-hours to write the first version of Spacewar. Steve Russell wrote Spacewar on a PDP-1, an early DEC (Digital Equipment Corporation) interactive mini computer which used a cathode-ray tube type display and keyboard input. The computer was a donation to MIT from DEC, who hoped MIT's think tank would be able to do something remarkable with their product. A computer game called Spacewar was the last thing DEC expected who later provided the game as a diagnostic program for their customers. Russell never profited from Spacewars.

The PDP-1's operating system was the first to allow multiple users to share the computer simultaneously. This was perfect for playing Spacewar, which was a two-player game involving warring spaceships firing photon torpedoes. Each player could maneuver a spaceship and score by firing missiles at his opponent while avoiding the gravitational pull of the sun. Try playing a replica** of the computer game for yourselves. It still holds today up as a great way to waste a few hours. By the mid-sixties, when computer time was still very expensive, Spacewar could be found on nearly every research computer in the country. Steve Russell transferred to Stanford University, where he introduced computer game programming and Spacewar to an engineering student called Nolan Bushnell. Bushnell went on to write the first coin-operated computer arcade game and start Atari Computers.

*An interesting sidenote is that "Doc" Smith, besides being a great science fiction writer, held a Ph.D. in chemical engineering and was the researcher who figured out how to get powdered sugar to stick to doughnuts.

**Spacewar! was conceived in 1961 by Martin Graetz, Steve Russell, and Wayne Wiitanen. It was first realized on the PDP-1 in 1962 by Steve Russell, Peter Samson, Dan Edwards and Martin Graetz, together with Alan Kotok, Steve Piner and Robert A. Saunders.

The History of the Integrated Circuit aka Microchip

2009-07-03T17:11:00.000-07:00

In designing a complex electronic machine like a computer it was always necessary to increase the number of components involved in order to make technical advances. The monolithic (formed from a single crystal) integrated circuit placed the previously separated transistors, resistors, capacitors and all the connecting wiring onto a single crystal (or 'chip') made of semiconductor material. Kilby used germanium and Noyce used silicon for the semiconductor material.

Patents for the Integrated Circuit

In 1959 both parties applied for patents. Jack Kilby and Texas Instruments received U.S. patent #3,138,743 for miniaturized electronic circuits. Robert Noyce and the Fairchild Semiconductor Corporation received U.S. patent #2,981,877 for a silicon based integrated circuit. The two companies wisely decided to cross license their technologies after several years of legal battles, creating a global market now worth about $1 trillion a year.

Commercial Release

In 1961 the first commercially available integrated circuits came from the Fairchild Semiconductor Corporation. All computers then started to be made using chips instead of the individual transistors and their accompanying parts. Texas Instruments first used the chips in Air Force computers and the Minuteman Missile in 1962. They later used the chips to produce the first electronic portable calculators. The original IC had only one transistor, three resistors and one capacitor and was the size of an adult's pinkie finger. Today an IC smaller than a penny can hold 125 million transistors.

Jack Kilby holds patents on over sixty inventions and is also well known as the inventor of the portable calculator (1967). In 1970 he was awarded the National Medal of Science. Robert Noyce, with sixteen patents to his name, founded Intel, the company responsible for the invention of the microprocessor, in 1968. But for both men the invention of the integrated circuit stands historically as one of the most important innovations of mankind. Almost all modern products use chip technology.

FORTRAN - The First Successful High Level Programming Language - Invented by John Backus and IBM

2009-07-03T17:10:00.000-07:00

FORTRAN or formula translation, the first high level programming language, was invented by John Backus for IBM, in 1954, and released commercially, in 1957. It is still used today for programming scientific and mathematical applications. Fortran began as a digital code interpreter for the IBM 701 and was originally named Speedcoding. John Backus wanted a programming language closer to human language, which is the definition of a high level language, other high language programs include Ada, Algol, BASIC, COBOL, C, C++, LISP, Pascal, and Prolog.

The first generation of codes used to program a computer, was called machine language or machine code, it is the only language a computer really understands, a sequence of 0s and 1s that the computer's controls interprets as instructions, electrically. The second generation of code was called assembly language, assembly language turns the sequences of 0s and 1s into human words like 'add'. Assembly language is always translated back into machine code by programs called assemblers.

The third generation of code, was called high level language or HLL, which has human sounding words and syntax (like words in a sentence). In order for the computer to understand any HLL, a compiler translates the high level language into either assembly language or machine code. All programming languages need to be eventually translated into machine code for a computer to use the instructions they contain.

John Backus headed the IBM team of researchers, at the Watson Scientific Laboratory, that invented Fortran. On the IBM team were the notable names of scientists like; Sheldon F. Best, Harlan Herrick (Harlan Herrick ran the first successful fortran program), Peter Sheridan, Roy Nutt, Robert Nelson, Irving Ziller, Richard Goldberg, Lois Haibt and David Sayre. The IBM team didn't invent HLL or the idea of compiling programming language into machine code, but Fortran was the first successful HLL and the Fortran I compiler holds the record for translating code for over 20 years. The first computer to run the first compiler was the IBM 704, which John Backus helped design.

Fortran is now over forty years old and remains the top language in scientific and industrial programming, of course it has constantly been updated. The invention of Fortran began a $24 million dollar computer software industry and began the development of other high level programming languages, Fortran has been used for programming video games, air traffic control systems, payroll calculations, numerous scientific and military applications and parallel computer research. John Backus won the 1993 National Academy of Engineering's Charles Stark Draper Prize, the highest national prize awarded in engineering, for the invention of Fortran.

The IBM 701 - General Purpose Computer

2009-07-03T17:09:00.000-07:00

The year 1953 saw the development of IBM's 701 EDPM, which, according to IBM, was the first commercially successful general-purpose computer. The 701's invention was due in part to the Korean War effort. Inventor, Thomas Johnson Watson Junior wanted to contribute what he called a "defense calculator" to aid in the United Nations' policing of Korea. One obstacle he had to overcome was in convincing his father, Thomas Johnson Watson Senior (IBM's CEO) that the new computer would not harm IBM's profitable punch card processing business. The 701s were incompatible with IBM's punched card processing equipment, a big moneymaker for IBM.

Only nineteen 701s were manufactured (the machine could be rented for $15,000 per month). The first 701 went to IBM's world headquarters in New York. Three went to atomic research laboratories. Eight went to aircraft companies. Three went to other research facilities. Two went to government agencies, including the first use of a computer by the United States Department of Defense. Two went to the navy and the last machine went to the United States Weather Bureau in early 1955.

Features of the 701

The 1953 built 701 had electrostatic storage tube memory, used magnetic tape to store information, and had binary, fixed-point, single address hardware. The speed of the 701 computers was limited by the speed of its memory; the processing units in the machines were about 10 times faster than the core memory. The 701 also led to the development of the programming language FORTRAN.

The IBM 704

In 1956, a significant upgrade to the 701 appeared. The IBM 704 was considered an early super-computer and the first machine to incorporate floating-point hardware. The 704 used magnetic core memory that was faster and more reliable than the magnetic drum storage found in the 701.

The IBM 7090

Also part of the 700 series, the IBM 7090 was the first commercial transistorized computer. Built in 1960, the 7090 computer was the fastest computer in the world. IBM dominated the mainframe and minicomputer market for the next two decades with its 700 series.

The IBM 650

After releasing the 700 series, IBM built the 650 EDPM, a computer compatible with its earlier 600 calculator series. The 650 used the same card processing peripherals as the earlier calculators, starting the trend for loyal customers to upgrade. The 650s were IBM's first mass-produced computers (universities were offered a 60% discount).

The IBM PC

In 1981, IBM created its first personal home-use computer called the IBM PC, another milestone in computer history.

The History of the UNIVAC Computer - J. Presper Eckert and John Mauchly

2009-07-03T17:08:00.000-07:00

The Universal Automatic Computer or UNIVAC was a computer milestone achieved by Dr. Presper Eckert and Dr. John Mauchly, the team that invented the ENIAC computer.

J Presper Eckert and John Mauchly, after leaving the academic environment of The Moore School of Engineering to start their own computer business, found their first client was the United States Census Bureau. The Bureau needed a new computer to deal with the exploding U.S. population (the beginning of the famous baby boom). In April 1946, a $300,000 deposit was given to Eckert and Mauchly for the research into a new computer called the UNIVAC.

UNIVAC Computer

The research for the project proceeded badly, and it was not until 1948 that the actual design and contract was finalized. The Census Bureau's ceiling for the project was $400,000. J Presper Eckert and John Mauchly were prepared to absorb any overrun in costs in hopes of recouping from future service contracts, but the economics of the situation brought the inventors to the edge of bankruptcy.

In 1950, Eckert and Mauchly were bailed out of financial trouble by Remington Rand Inc. (manufacturers of electric razors), and the "Eckert-Mauchly Computer Corporation" became the "Univac Division of Remington Rand." Remington Rand's lawyers unsuccessfully tried to re-negotiate the government contract for additional money. Under threat of legal action, however, Remington Rand had no choice but to complete the UNIVAC at the original price.

On March 31, 1951, the Census Bureau accepted delivery of the first UNIVAC computer. The final cost of constructing the first UNIVAC was close to one million dollars. Forty-six UNIVAC computers were built for both government and business uses. Remington Rand became the first American manufacturers of a commercial computer system. Their first non-government contract was for General Electric's Appliance Park facility in Louisville, Kentucky, who used the UNIVAC computer for a payroll application.

The History of the Transistor - John Bardeen, Walter Brattain, and William Shockley

2009-07-03T17:07:00.002-07:00

The transistor is an influential invention that changed the course of history for computers. The first generation of computers used vacuum tubes; the second generation of computers used transistors; the third generation of computers used integrated circuits; and the fourth generation of computers used microprocessors.

John Bardeen, William Shockley, and Walter Brattain, scientists at the Bell Telephone Laboratories in Murray Hill, New Jersey, were researching the behavior of crystals (germanium) as semi-conductors in an attempt to replace vacuum tubes as mechanical relays in telecommunications. The vacuum tube, used to amplify music and voice, made long-distance calling practical, but the tubes consumed power, created heat and burned out rapidly, requiring high maintenance.

The team's research was about to come to a fruitless end when a last attempt to try a purer substance as a contact point lead to the invention of the "point-contact" transistor amplifier. In 1956, the team received the Nobel Prize in Physics for the invention of the transistor.

A transistor is a device composed of semi-conductor material that can both conduct and insulate (e.g. germanium and silicon). Transistors switch and modulate electronic current. Before transistors, digital circuits were composed of vacuum tubes. [Read the ENIAC story to learn all about the disadvantages of vacuum tubes in computers.] The transistor was the first device designed to act as both a transmitter, converting sound waves into electronic waves, and resistor, controlling electronic current. The name transistor comes from the 'trans' of transmitter and 'sistor' of resistor.

John Bardeen and Walter Brattain took out a patent for their transistor. William Shockley applied for a patent for the transistor effect and a transistor amplifier. Transistors transformed the world of electronics and had a huge impact on computer design. Transistors made of semiconductors replaced tubes in the construction of computers. By replacing bulky and unreliable vacuum tubes with transistors, computers could now perform the same functions, using less power and space.

The Mark 1 Computer - The Williams Tube - Frederick Williams and Tom Kilburn

2009-07-03T17:07:00.001-07:00

By 1946, a winner in the data-storage game emerged that would dominate the computer field for the next several years. Sir Frederick Williams and Tom Kilburn co-invented the Williams-Kilburn Tube (or Williams Tube), a type of altered cathode-ray tube. Scientists had conducted research on cathode-ray tubes serving as computer data storage since the early 1940s.

The illustration to the right is an example of the video display terminal used with the Manchester computer. The terminal mirrored what was happening within the Williams Tube. A metal detector plate placed close to the surface of the tube, detected changes in electrical discharges. Since the metal plate would obscure a clear view of the tube, the technicians could monitor the tubes used a video screen. Each dot on the screen represented a dot on the tube's surface; the dots on the tube's surface worked as capacitors that were either charged and bright or uncharged and dark. The information translated into binary code (0,1 or dark, bright) became a way to program the computer.

The Williams Tube provided the first large amount of random access memory (RAM), and it was a convenient method of data-storage. It did not require rewiring each time the data was changed, and programming the computer went much faster. It became the dominant form of computer memory until outdated by core memory in 1955.

The ENIAC I Computer - J Presper Eckert and John Mauchly

2009-07-03T17:05:00.000-07:00

In 1946, John Mauchly and J Presper Eckert developed the ENIAC I (Electrical Numerical Integrator And Calculator). The U.S. military sponsored their research; they needed a calculating device for writing artillery-firing tables (the settings used for different weapons under varied conditions for target accuracy). The Ballistics Research Laboratory, or BRL (the branch of the military responsible for calculating the tables), heard about John Mauchly's research at the University of Pennsylvania's Moore School of Electrical Engineering. John Mauchly had previously created several calculating machines, some with small electric motors inside. He had begun designing (1942) a better calculating machine based on the work of John Atanasoff that would use vacuum tubes to speed up calculations.

The Harvard MARK I Computer - Howard Aiken and Grace Hopper

2009-07-03T17:03:00.000-07:00

Howard Aiken and Grace Hopper designed the MARK series of computers at Harvard University. The MARK series of computers began with the Mark I in 1944. Imagine a giant roomful of noisy, clicking metal parts, 55 feet long and 8 feet high. The 5-ton device contained almost 760,000 separate pieces. Used by the US Navy for gunnery and ballistic calculations, the Mark I was in operation until 1959.

The computer, controlled by pre-punched paper tape, could carry out addition, subtraction, multiplication, division and reference to previous results. It had special subroutines for logarithms and trigonometric functions and used 23 decimal place numbers. Data was stored and counted mechanically using 3000 decimal storage wheels, 1400 rotary dial switches, and 500 miles of wire. Its electromagnetic relays classified the machine as a relay computer. All output was displayed on an electric typewriter. By today's standards, the Mark I was slow, requiring 3-5 seconds for a multiplication operation.

The Atanasoff-Berry Computer the First Electronic Computer - John Atanasoff and Clifford Berry

2009-07-03T17:02:00.000-07:00

Professor John Atanasoff and graduate student Clifford Berry built the world's first electronic-digital computer at Iowa State University between 1939 and 1942. The Atanasoff-Berry Computer represented several innovations in computing, including a binary system of arithmetic, parallel processing, regenerative memory, and a separation of memory and computing functions.

Presper Eckert and John Mauchly were the first to patent a digital computing device, the ENIAC computer. A patent infringement case (Sperry Rand Vs. Honeywell, 1973) voided the ENIAC patent as a derivative of John Atanasoff's invention. Atanasoff was quite generous in stating, "there is enough credit for everyone in the invention and development of the electronic computer." Eckert and Mauchly received most of the credit for inventing the first electronic-digital computer. Historians now say that the Atanasoff-Berry computer was the first.

Konrad Zuse

2009-07-03T17:00:00.000-07:00

Konrad Zuse (1910-1995) was a construction engineer for the Henschel Aircraft Company in Berlin, Germany at the beginning of WWII. Konrad Zuse earned the semiofficial title of "inventor of the modern computer" for his series of automatic calculators, which he invented to help him with his lengthy engineering calculations. Zuse has modestly dismissed the title while praising many of the inventions of his contemporaries and successors as being equally if not more important than his own.

One of the most difficult aspects of doing a large calculation with either a slide rule or a mechanical adding machine is keeping track of all intermediate results and using them, in their proper place, in later steps of the calculation. Konrad Zuse wanted to overcome that difficulty. He realized that an automatic-calculator device would require three basic elements: a control, a memory, and a calculator for the arithmetic.

Computer Parts

2009-07-03T16:54:00.000-07:00

Tower Case

This is the most common case today. Tower cases come in three sizes - mini, midi or maxi. Mini is the smallest and maxi is the largest.

Tower cases have lots of room available for you extra drives and other accessories.

The most important thing about the case is that it has enough space for the components inside to run smoothly. The case should be able to fit all the components. Other than that, you can choose a case by design preference.

Power Supply

Supplies power to all the parts in the computer. Usually depends on the voltage of the country. The power supply must be able to supply enough power to the components. Generally, higher end parts take up more power.

The power supply must be able to provide enough power to the parts. Generally, the higher end the parts, the more power they use. Make sure it has the same voltage as all the power outlets in your house.

Cooling System

The cooling system keeps the computer parts cool when running. The most common way is to use case fans. Cheap fans are noisier and might not last as long. One of the more recent ways of cooling has been with liquid-cooling. Using a mixture of water and antifreeze, liquid cooling is much more efficient than fans, and is a lot quieter. However, if any of this liquid was to leak onto the motherboard or other components, they will definitely break. Liquid-cooling is generally not recommended to anyone building a computer, and best left up to computer manufacturers.

High end video cards and processors create more heat, so the cooler the inside of the computer is, the better. If a component like the CPU overheats, it will most likely be destroyed.

The cooling system should run smoothly and quietly. It must be strong enough to keep the parts at an average temperature (70-90 Celsius).

Motherboard

The motherboard is the main circuit board of the computer. It holds the CPU, RAM modules and most of the circuitry. All adapter cards plug into your motherboard. The motherboard defines how much RAM, adapter cards, and the type of CPU the computer is going to have.

The Socket Connector is the where the CPU is plugged in. There are different types of plugs that go with different CPUs.

The DDR RAM Slots is where the RAM is plugged in. They are important because they define how much RAM you are able to have on the computer.

The hard drive is plugged into the IDE Headers.

PCI slots are where adapter cards are connected to. Cards such as sound cards and extra USB cards are all plugged into the PCI slots.

The PCI express slot, or AGP slot, is where the video card is plugged into. They are a special kind of PCI slot that is made specifically for video cards.

The back panel connectors are basically where all USB devices are plugged into. Most motherboards include a mouse connector, PS/2 Keyboard, USB pots, Serial port, parallel port, external audio jacks, AGP slot, and a MIDI port in the back panel connectors. If there is onboard sound on the motherboard, the speakers are plugged into the back panel connectors.

Terms:

Keyboard and Mouse Port - Ports where the keyboard and mouse are plugged into/
USB Ports - A high speed, universal method of plugging extra peripherals into the computer.
Serial Port - Ports that are used for plugging in joysticks and other game controllers.
Parallel Port - Where the printer is plugged in.
MIDI - A port where MIDI capable instruments can be plugged into.
Onboard sound - A sound card has already been installed on the motherboard without taking up a PCI slot.
AGP port - The monitor is plugged into this port.

Today, motherboards usually come with onboard sound. RAM limit can vary from a maximum of 2GB to 8GB. A lot more focus has been put on PCI express and AGP slots because of the high demand for video cards, and the ever-increasing level of graphics. PCI slots are being used less and less because they aren't needed as much. Things like USB cards and sound cards are usually included in the motherboard nowadays.

Motherboards should be able to hold all the components. Choose a motherboard with more RAM slots so you have the room to upgrade. The more RAM the better. Make sure the motherboard has at least two PCI slots and one AGP or PCI-Express slots. The PCI slots hold adapter cards, and the AGP or PCI-Express slots hold the GPU. Motherboards should also come with extra onboard ports. This saves an adapter slot.

Processor (CPU)

The CPU, or the Central Processing Unit, is the brain of the computer and the most important chip in the computer. When you run a program, the CPU performs the calculations and carries out the commands.

Modern processors contain millions of transistors (miniature electronic switches) that are etched onto a small silicon square called a die. The die is about the width of a thumb.

The processor generates quite a lot of heat, so it always has a heat sink and fan that lies on top of it, and prevents it from getting too hot.

The faster the CPU the better. Speed is measured in MHz (megahertz) or GHz (gigahertz). Make sure that the CPU is compatible with the motherboard and have the same type of socket. Most new processors are 64-bit. This means that they support the upcoming Windows Vista. 64-bit processors can also run 32-bit applications, but not the other way around. Try to go for 64-bit, as 32-bit processors will soon be out of date.

Dual Core processors combine two or more processors into a single package. This will speed up the CPU drastically, and it enables optimal speed when running many programs at the same time.

Memory (RAM)

The memory holds "short term" information for the processor to use. This may be a program, or a set of data. The processor is able to retrieve information from the RAM at very high speeds. When the processor needs information that isn't in the RAM, it has to read the information from the hard drive, which is much slower.

The more RAM the better, as it makes the whole system run faster.

The RAM modules are slotted into the RAM slots, which are located next to the processor socket on the motherboard.

DDR2 models are the newest type of RAM. It doubles the speed of data transfer between the RAM and CPU compared to the old DDR model. Make sure that the RAM is compatible with the motherboard. The more RAM the better; this is especially true when running operating systems such as WindowsXP.

Video Card (GPU - Graphics Processing Unit)

The video card sends the visual output produced by a program on to the monitor, which displays that on the screen. For gamers and others who use very high end graphics or special video work regularly, the GPU will be the most expensive part of the computer. These cards also run very hot, and most contain a fan on the side.

To get the best performance from a video card, you need a PCI-Express or an AGP slot. If it is used on a normal PCI slot, it will run much slower. Most video card manufacturers provide a benchmark figure of speed. You can compare these. GPUs also carry onboard RAM: the more the better. Make sure that the card has driver support for OpenGL and Direct3D. These are subsystems that are used in games and other online applications.

Video cards also come with a refresh rate. This shows how many times the monitor refreshes each pixel. The higher the refresh rate, the better. Lower refresh rates tend to give people head-aches.

DVD / CD Drive

CD and DVD drives allow the computer to read and burn CDs and DVDs. DVDs can hold a lot more data than CDs. Different kinds of CDs and DVDs can be rewritten, or played on a DVD player.

Make sure that the drive has a high access time. Access time is the actual time require for the CD or DVD drive to locate a specific file on the disc.

Just like a hard drive, the CD/DVD drive uses a special set of onboard RAM modules. The larger the cache, the fewer interruptions in the transfer of data.

Some kinds of CD/DVD can also burn and rewrite CDs and DVDs. This is not necessary, but a good feature to have.

Hard Drives

The hard drive is where all the information and programs on the computer is stored. The faster the rpm (revolutions per minute) of the platters (spinning discs in the hard drive that store data magnetically) in the hard drive, the faster it can read and retrieve data. The main concern about hard drive is the amount of space. Typical hard drives are around 100 GB.

Storage capacity is the biggest concern with hard drives. The more storage capacity, the more you can store on the hard drive. Choose a hard drive with a storage capacity that meets your needs, although the more space the better.

Access time a hard drive measures how fast the drive can read and write data. Choose a hard drive that has at least an access time of 10ms.

RPM is measures how fast the platters in the hard drive are moving. Choose a hard drive with a high RPM. Common RPMs are 7200 and 10,000.

The cache of the hard drive stores data that is used frequently. The larger the cache, the more information the hard drive doesn't have to re-read each time it is opened.

Floppy drive

Floppy discs are being used less and less because they are unreliable and have a very short life span. The floppy drive is optional.

Monitor

Monitors are available in different size. The most common sizes are 17, 19 and 21 inches. This is measured diagonally. They display what you are doing on the computer.

Size is the main thing to consider when buying a monitor. Most monitors today have a flat screen. This makes the image much clearer. Also try to find a monitor that decreases the amount of electromagnetic radiation created.

Mouse and Keyboard

Mice control the mouse on screen. Wireless and optical mice are used more because they are more accurate. Trackball mice get dirty and need cleaning every once in a while.

Keyboards allow you u to type on the computer. Most keyboards today have 103 keys, but some have extra buttons that you can program to do what you want.

Most users will want a 103 keyboard. There are some ergonomic keyboards that shape the hand and make typing easier, this is just a preference.

Mice are also more of a preference. Try to stick with optical mice, as they have a longer lifespan.

History of Modern Computer

2009-06-30T16:21:00.000-07:00

History of Computers

Computer History Year/Enter	Computer History Inventors/Inventions	Computer History Description of Event
1936	Konrad Zuse - Z1 Computer	First freely programmable computer.
1942	John Atanasoff & Clifford Berry ABC Computer	Who was first in the computing biz is not always as easy as ABC.
1944	Howard Aiken & Grace Hopper Harvard Mark I Computer	The Harvard Mark 1 computer.
1946	John Presper Eckert & John W. Mauchly ENIAC 1 Computer	20,000 vacuum tubes later...
1948	Frederic Williams & Tom Kilburn Manchester Baby Computer & The Williams Tube	Baby and the Williams Tube turn on the memories.
1947/48	John Bardeen, Walter Brattain & Wiliam Shockley The Transistor	No, a transistor is not a computer, but this invention greatly affected the history of computers.
1951	John Presper Eckert & John W. Mauchly UNIVAC Computer	First commercial computer & able to pick presidential winners.
1953	International Business Machines IBM 701 EDPM Computer	IBM enters into 'The History of Computers'.
1954	John Backus & IBM FORTRAN Computer Programming Language	The first successful high level programming language.
1955 (In Use 1959)	Stanford Research Institute, Bank of America, and General Electric ERMA and MICR	The first bank industry computer - also MICR (magnetic ink character recognition) for reading checks.
1958	Jack Kilby & Robert Noyce The Integrated Circuit	Otherwise known as 'The Chip'
1962	Steve Russell & MIT Spacewar Computer Game	The first computer game invented.
1964	Douglas Engelbart Computer Mouse & Windows	Nicknamed the mouse because the tail came out the end.
1969	ARPAnet	The original Internet.
1970	Intel 1103 Computer Memory	The world's first available dynamic RAM chip.
1971	Faggin, Hoff & Mazor Intel 4004 Computer Microprocessor	The first microprocessor.
1971	Alan Shugart &IBM The "Floppy" Disk	Nicknamed the "Floppy" for its flexibility.
1973	Robert Metcalfe & Xerox The Ethernet Computer Networking	Networking.
1974/75	Scelbi & Mark-8 Altair & IBM 5100 Computers	The first consumer computers.
1976/77	Apple I, II & TRS-80 & Commodore Pet Computers	More first consumer computers.
1978	Dan Bricklin & Bob Frankston VisiCalc Spreadsheet Software	Any product that pays for itself in two weeks is a surefire winner.
1979	Seymour Rubenstein & Rob Barnaby WordStar Software	Word Processors.
1981	IBM The IBM PC - Home Computer	From an "Acorn" grows a personal computer revolution
1981	Microsoft MS-DOS Computer Operating System	From "Quick And Dirty" comes the operating system of the century.
1983	Apple Lisa Computer	The first home computer with a GUI, graphical user interface.
1984	Apple Macintosh Computer	The more affordable home computer with a GUI.
1985	Microsoft Windows	Microsoft begins the friendly war with Apple.
SERIES	TO BE	CONTINUED

History of Modern Computer

High-Speed Memory

Other Notable Early Computers

ENIAC and EDVAC

The Manchester Machine

Turing's Automatic Computing Engine

Colossus

Atanasoff

Electromechanical versus Electronic Computation

The Universal Turing Machine

Analog computers

Babbage

The Colossus

Who Built The First Modern Computer?

Enigma and Lorenz

A Toe In The Door

An Example of the Computer Modern Roman Font

Modern computer technology benefits North Cotabato mentors

Ada Lovelace - The Enchantress of Number or the most Overrated Figure in the History of Computing?

The Meaning of Invention

The First Modern Computer - The Case for Baby, the Manchester Mk I Prototype

The Art of Turing Completion

The First Railway Station: Unlikely Home for the First Computer

Misinformation and the Evolution of Early Computers

The Moore School Lectures and the British Lead in Stored Program Computer Development (1946 -1953)

The Evolution of the Modern Computer (1934 to 1950): An Open Source Graphical History

Vannevar Bush and The Limits of Prescience

Charles Babbage and Howard Aiken. How the Analytical Engine influenced the IBM Automatic Sequence Controlled Calculator aka The Harvard Mk I

History of Computer

The Invention of the Intel 1103 - The World's First Available DRAM Chip

ARPAnet - The First Internet

The History of the Computer Mouse and the Prototype for Windows - Douglas Engelbart

Spacewar! : The first computer game invented by Steve Russell

The History of the Integrated Circuit aka Microchip

Patents for the Integrated Circuit

Commercial Release

FORTRAN - The First Successful High Level Programming Language - Invented by John Backus and IBM

The IBM 701 - General Purpose Computer

Features of the 701

The IBM 704

The IBM 7090

The IBM 650

The IBM PC

The History of the UNIVAC Computer - J. Presper Eckert and John Mauchly

The History of the Transistor - John Bardeen, Walter Brattain, and William Shockley

The Mark 1 Computer - The Williams Tube - Frederick Williams and Tom Kilburn

The ENIAC I Computer - J Presper Eckert and John Mauchly

The Harvard MARK I Computer - Howard Aiken and Grace Hopper

Sponsored Links

The Atanasoff-Berry Computer the First Electronic Computer - John Atanasoff and Clifford Berry

Konrad Zuse

Computer Parts

Tower Case

Power Supply

Cooling System

Motherboard

Processor (CPU)

Memory (RAM)

Video Card (GPU - Graphics Processing Unit)

DVD / CD Drive

Hard Drives

Floppy drive

Monitor

Mouse and Keyboard

History of Modern Computer

History of Computers