First Generation Electronic Computers

(1945-1953)

With the onset of the Second World War, governments sought to develop computers to exploit their potential strategic importance. This increased funding for computer development projects hastened technical progress. By 1941 German engineer Konrad Zuse had developed a computer, the Z3, to design airplanes and missiles. The Allied forces, however, made greater strides in developing powerful computers. In 1943, the British completed a secret code-breaking computer called Colossus to decode German messages. The Colossus's impact on the development of the computer industry was rather limited for two important reasons. First, Colossus was not a general-purpose computer; it was only designed to decode secret messages. Second, the existence of the machine was kept secret until decades after the war.

American efforts produced a broader achievement. Howard H. Aiken (1900-1973), a Harvard engineer working with IBM, succeeded in producing an all-electronic calculator by 1944. The purpose of the computer was to create ballistic charts for the U.S. Navy. It was about half as long as a football field and contained about 500 miles of wiring. The Harvard-IBM Automatic Sequence Controlled Calculator, or Mark I for short, was a electronic relay computer. It used electromagnetic signals to move mechanical parts. The machine was slow (taking 3-5 seconds per calculation) and inflexible (in that sequences of calculations could not change); but it could perform basic arithmetic as well as more complex equations.

Electronic Numerical Integrator and Computer (ENIAC)

Another computer development spurred by the war was the Electronic Numerical Integrator and Computer (ENIAC), produced by a partnership between the U.S. government and the University of Pennsylvania. Consisting of 18,000 vacuum tubes, 70,000 resistors and 5 million soldered joints, the computer was such a massive piece of machinery that it consumed 160 kilowatts of electrical power, enough energy to dim the lights in an entire section of Philadelphia. Developed by John Presper Eckert (1919-1995) and John W. Mauchly (1907-1980), ENIAC, unlike the Colossus and Mark I, was a general-purpose computer that computed at speeds 1,000 times faster than Mark I.

In the mid-1940's John von Neumann (1903-1957) joined the University of Pennsylvania team, initiating concepts in computer design that remained central to computer engineering for the next 40 years. Von Neumann designed the Electronic Discrete Variable Automatic Computer (EDVAC) in 1945 with a memory to hold both a stored program as well as data. This "stored memory" technique as well as the "conditional control transfer," that allowed the computer to be stopped at any point and then resumed, allowed for greater versatility in computer programming. The key element to the von Neumann architecture was the central processing unit, which allowed all computer functions to be coordinated through a single source. In 1951, the UNIVAC I (Universal Automatic Computer), built by Remington Rand, became one of the first commercially available computers to take advantage of these advances. Both the U.S. Census Bureau and General Electric owned UNIVACs. One of UNIVAC's impressive early achievements was predicting the winner of the 1952 presidential election, Dwight D. Eisenhower.

First generation computers were characterized by the fact that operating instructions were made-to-order for the specific task for which the computer was to be used. Each computer had a different binary-coded program called a machine language that told it how to operate. This made the computer difficult to program and limited its versatility and speed. Other distinctive features of first generation computers were the use of vacuum tubes (responsible for their breathtaking size) and magnetic drums for data storage.

Three machines have been promoted at various times as the first electronic computers. These machines used electronic switches, in the form of vacuum tubes, instead of electromechanical relays. In principle the electronic switches would be more reliable, since they would have no moving parts that would wear out, but the technology was still new at that time and the tubes were comparable to relays in reliability. Electronic components had one major benefit, however: they could "open'' and "close'' about 1,000 times faster than mechanical switches.

The earliest attempt to build an electronic computer was by J. V. Atanasoff, a professor of physics and mathematics at Iowa State, in 1937. Atanasoff set out to build a machine that would help his graduate students solve systems of partial differential equations. By 1941 he and graduate student Clifford Berry had succeeded in building a machine that could solve 29 simultaneous equations with 29 unknowns. However, the machine was not programmable, and was more of an electronic calculator.

A second early electronic machine was Colossus, designed by Alan Turing for the British military in 1943. This machine played an important role in breaking codes used by the German army in World War II. Turing's main contribution to the field of computer science was the idea of the Turing machine, a mathematical formalism widely used in the study of computable functions. The existence of Colossus was kept secret until long after the war ended, and the credit due to Turing and his colleagues for designing one of the first working electronic computers was slow in coming.

The first general purpose programmable electronic computer was the Electronic Numerical Integrator and Computer (ENIAC), built by J. Presper Eckert and John V. Mauchly at the University of Pennsylvania. Work began in 1943, funded by the Army Ordnance Department, which needed a way to compute ballistics during World War II. The machine wasn't completed until 1945, but then it was used extensively for calculations during the design of the hydrogen bomb. By the time it was decommissioned in 1955 it had been used for research on the design of wind tunnels, random number generators, and weather prediction. Eckert, Mauchly, and John von Neumann, a consultant to the ENIAC project, began work on a new machine before ENIAC was finished. The main contribution of EDVAC, their new project, was the notion of a stored program. There is some controversy over who deserves the credit for this idea, but none over how important the idea was to the future of general purpose computers. ENIAC was controlled by a set of external switches and dials; to change the program required physically altering the settings on these controls. These controls also limited the speed of the internal electronic operations. Through the use of a memory that was large enough to hold both instructions and data, and using the program stored in memory to control the order of arithmetic operations, EDVAC was able to run orders of magnitude faster than ENIAC. By storing instructions in the same medium as data, designers could concentrate on improving the internal structure of the machine without worrying about matching it to the speed of an external control.

Regardless of who deserves the credit for the stored program idea, the EDVAC project is significant as an example of the power of interdisciplinary projects that characterize modern computational science. By recognizing that functions, in the form of a sequence of instructions for a computer, can be encoded as numbers, the EDVAC group knew the instructions could be stored in the computer's memory along with numerical data. The notion of using numbers to represent functions was a key step used by Goedel in his incompleteness theorem in 1937, work which von Neumann, as a logician, was quite familiar with. Von Neumann's background in logic, combined with Eckert and Mauchly's electrical engineering skills, formed a very powerful interdisciplinary team.

Software technology during this period was very primitive. The first programs were written out in machine code, i.e. programmers directly wrote down the numbers that corresponded to the instructions they wanted to store in memory. By the 1950s programmers were using a symbolic notation, known as assembly language, then hand-translating the symbolic notation into machine code. Later programs known as assemblers performed the translation task.

As primitive as they were, these first electronic machines were quite useful in applied science and engineering. Atanasoff estimated that it would take eight hours to solve a set of equations with eight unknowns using a Marchant calculator, and 381 hours to solve 29 equations for 29 unknowns. The Atanasoff-Berry computer was able to complete the task in under an hour. The first problem run on the ENIAC, a numerical simulation used in the design of the hydrogen bomb, required 20 seconds, as opposed to forty hours using mechanical calculators. Eckert and Mauchly later developed what was arguably the first commercially successful computer, the UNIVAC; in 1952, 45 minutes after the polls closed and with 7% of the vote counted, UNIVAC predicted Eisenhower would defeat Stevenson with 438 electoral votes (he ended up with 442).

Year wise summery of development

1945-1946: ENIAC, designed by J.Presper Eckert and John Maulchy, is unveiled at the University of Pennsylvania on February 14. Arthur Burks, Herman Goldstine, and John von Neumann write "Preliminary Discussion of the Logical Design of an Electronic Computing Instrument." . The American Institute of Electrical Engineers establishes a Subcommittee on Large-Scale Calculating Devices -- the orign of today's IEEE Computer Society. Alan Turing publishes a report on his design for ACE (Automatic Computing Engine), featuring random extraction of information.

Binac (Binary Automatic Computer), the first computer to operate in real time, is started by Eckert and Mauchly; it is completed in 1949. ENIAC (Electronic Numerical Integrator and Computer), with 18,000 vacuum tubes, is dedicated at the University of Pennsylvania. It was 8 by 100 feet and weighed 80 tons. It could do 5,000 additions and 360 multiplications per second.

Eckert-Mauchly Computer Corporation is formed as the Electronic Control Co. to design a Universal Automatic Computer (Univac). Term bit for binary digit is used for first time by John Tukey.

1947: Alan M. Turing publishes an article on Intelligent Machinery which launches artificial intelligence. Association for Computing Machinery (ACM) is formed. Aiken and his team complete the " Harvard Mark II".First actual case of bug being found.Magnetic core memory is patented.The magnetic drum memory is independently invented by several people.

1948: Wallace Eckert of IBM, with his team, completes the "SSEC".Newman, Freddie C. Williams, and their team complete their "Mark I".The ENIAC is improved, using ideas from Clipper and Metropolis.IBM introduces the "IBM 604". Claude Shannon publishes "A Mathematical Theory of Communication" formulating the modern understanding of the communication process. EDSAC (Electronic Delay Storage Automatic Calculator) is developed at the University of Cambridge by Maurice V. Wilkes. On June 21, the Manchester Mark I, or "baby" machine, becomes the first operational stored-program digital computer. It used vacuum tube, or valve, circuits.

Richard Hamming devises a way to find and correct errors in blocks of data. The Hamming code is subsequently used in computer and telephone switching systems. The SSEC (Selective Sequene Electronic Calculator), using both electronics and relays, is dedicated on January 24. IBM introduces the 604 electronic calculator.

1949:The Whirlwind computer, constructed under the leadership of Jay Forrester at MIT to be the first real-time computer, is placed in service during the third quarter. It contained 5,000 vacuum tubes. EDSAC (Electronic Delayed Storage Automatic Computer), a stored-program computer built by Maurice Wilkes at Cambridge University, England, performs its first calculation on May 6. Short Order Code, developed by John Mauchly, is thought to be the first high-level programming language. Claude Shannon of MIT builds the first chess playing machine. 1949 - 1950

1950: The Pilot ACE is completed at England's National Physical Laboratory and runs its first program an May 10. Remington Rand buys the Eckert-Mauchly Computer Corporatin. The Standards Werstern Automatic Computer (SWAC), built under Harry Huskey's leadership, is dedicated at UCLA on August 17. Alan Turing publishes an article in the journal Mind establishing the criteria for the Turing Test of machine intelligence.

Maurice V. Wilkes at Cambridge University uses assembler (symbolic assembly language) on EDSAC. Remington-Rand acquires Eckert-Mauchly Computer Corp. SEAC (Standards Eastern Automatic Computer) is delivered to the National Bureau of Standards.

1951: Maurice V. Wilkes introduces the concept of microprogramming. IEEE Computer Society is formed. UNIVAC I is installed at the Bureau of Census using a magnetic tape unit as a buffer memory. Wang Laboratories, Inc. is founded by An Wang in Boston. Whirlwind computer becomes operational at MIT. It was the first real-time computer and was designed by Jay Forrester and Ken Olsen.

The first Univac I is delivered to the US Census Bureau in March. Jay Forrester files a patent application for the matrix core memory an May 11. William Shockley invents the junction transistor.David Wheeler, Maurice Wilkes, and Stanley Gill introduce sub-programs and the "Wheeler jump" as a means to implement them. Betty Holberton creates a short-merge generator, a predecessor of the compiler. Maurice Wilkes originates the concept of micro-programming, a technique providing an orderly approach to design a computer system's control section.

1952: Grace Murray Hopper develops A-0, the first compiler. The EDVAC runs its first production programon January 28.Illiac I is built at the University of Illinois, Urbana-Champaign; Ordvac is built by the US Armee. Both use von Neumann architecture. John von Neumann's IAS bit-parallel machine is completed in June for the Institute of Advanced Studies at Princeton, New Jersey.Thomas Watson Jr. becomes president of IBM. The Institute of Radio Engineers initiates the Transactions of the I.R.E. Electronic Group on Electronic Computers, a predecessor to the IEEE Transaction on Computers. On television, a Univac I predicts the outcome of the presidential election and expands the public consciousness regarding computers. The IBM 701--the Defense Calculator--is introduced in December.

First computer manual is written by Fred Gruenberger. IBM introduces the 701, its first electronic stored-program computer. Nixdorf Computer is founded in Germany. Remington-Rand acquires Engineering Research Associates (ERA). RCA develops Bizmac with iron-core memory and a magnetic drum supporting the first database. UNIVAC I predicts an Eisenhower landslide with 7% of the votes, just one hour after the polls close. U.S. Department of Justice sues IBM for monopolizing the punched-card accounting machine industry.

1953: Burroughs Corp. installs the Universal Digital Electronic Computer (UDEC) at Wayne State University. First high-speed printer is developed by Remington-Rand for use on the Univac. First magnetic tape device, the IBM 726, is introduced with 100 character-per-inch density and 75 inches-per-second speed. IBM ships its first stored-program computer, the 701. It is a vacuum tube, or first generation, computer.

After several years of development, LEO, a commercial version of EDSAC built by the Lyons Company in the UK, goes into service. The IBM 650, known as the Magnetic Drum Calculator, debuts and becomes the first mass-produced computer. Kenneth Olsen uses Jay Forrester's ferrite core memory to build the Memory Test computer.

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