ENIAC inventors John Mauchly and J. Presper Eckert proposed the EDVAC’s construction in August 1944, and design work for the EDVAC commenced before the ENIAC was fully operational. The design would implement a number of important architectural and logical improvements conceived during the ENIAC’s construction and would incorporate a high speed serial access memory. Like the ENIAC, the EDVAC was built for the U.S. Army’s Ballistics Research Laboratory at the Aberdeen Proving Ground by the University of Pennsylvania’s Moore School of Electrical Engineering. Eckert and Mauchly and the other ENIAC designers were joined by John von Neumann in a consulting role; von Neumann summarized and discussed logical design developments in the 1945 First Draft of a Report on the EDVAC. A contract to build the new computer was signed in April 1946 with an initial budget of US$100,000. The contract named the device the Electronic Discrete Variable Automatic Calculator. The final cost of EDVAC, however, was similar to the ENIAC’s, at just under $500,000. Technical description
The EDVAC was a binary serial computer with automatic addition, subtraction, multiplication, programmed division and automatic checking with an ultrasonic serial memory capacity of 1,000 44-bit words (later set to 1,024 words, thus giving a memory, in modern terms, of 5.5 kilobytes). Installation and operation
EDVAC was delivered to the Ballistics Research Laboratory in August 1949. After a number of problems had been discovered and solved, the computer began operation in 1951 although only on a limited basis. Its completion was delayed because of a dispute over patent rights between Eckert and Mauchly and the University of Pennsylvania, resulting in Eckert and Mauchly’s resignation and departure to form the Eckert–Mauchly Computer Corporation and taking most of the senior engineers with them. By 1960 EDVAC was running over 20 hours a day with error-free run time averaging eight hours. EDVAC received a number of upgrades including punch-card I/O in 1953, extra memory in slower magnetic drum form in 1954, and a floating point arithmetic unit in 1958. EDVAC ran until 1961 when it was replaced by BRLESC. During its operational life it proved to be reliable and productive for its time. Plankalkül (German pronunciation: [ˈplaːnkalkyːl], “Plan Calculus”) is a computer language designed for engineering purposes by Konrad Zuse between 1943 and 1945.
It was the first high-level non-von Neumann programming language to be designed for a computer. Also, notes survive with scribblings about such a plan calculation dating back to 1941. Plankalkül was not published at that time owing to a combination of factors such as conditions in wartime and postwar Germany and his efforts to commercialise the Z3 computer and its successors. By 1946, Zuse had written a book on the subject but this remained unpublished. In 1948 Zuse published a paper about the Plankalkül in the “Archiv der Mathematik” but still did not attract much feedback – for a long time to come programming a computer would only be thought of as programming with machine code. The Plankalkül was eventually more comprehensively published in 1972 and the first compiler for it was implemented in 1998.
Another independent implementation followed in the year 2000 by the Free University of Berlin. “Kalkül” means formal system – the Hilbert-style deduction system is for example originally called “Hilbert-Kalkül”, so Plankalkül means “formal system for planning”. A transistor is a semiconductor device used to amplify and switch electronic signals and power. It is composed of a semiconductor material with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor’s terminals changes the current flowing through another pair of terminals. Because the controlled (output) power can be higher than the controlling (input) power, a transistor can amplify a signal. Today, some transistors are packaged individually, but many more are found embedded in integrated circuits. The transistor is the fundamental building block of modern electronic devices, and is ubiquitous in modern electronic systems. Following its development in the early 1950s the transistor revolutionized the field of electronics, and paved the way for smaller and cheaper radios, calculators, and computers, among other things. Importance
The transistor is the key active component in practically all modern electronics. Many consider it to be one of the greatest inventions of the 20th century. Its importance in today’s society rests on its ability to be mass produced using a highly automated process (semiconductor device fabrication) that achieves astonishingly low per-transistor costs. The invention of the first transistor at Bell Labs was named an IEEE Milestone in 2009. Although several companies each produce over a billion individually packaged (known as discrete) transistors every year, the vast majority of transistors now are produced in integrated circuits (often shortened to IC, microchips or simply chips), along with diodes, resistors, capacitors and other electronic components, to produce complete electronic circuits. A logic gate consists of up to about twenty transistors whereas an advanced microprocessor, as of 2011, can use as many as 3 billion transistors (MOSFETs). “About 60 million transistors were built in 2002 … for [each] man, woman, and child on Earth.” The transistor’s low cost, flexibility, and reliability have made it a ubiquitous device.
Transistorized mechatronic circuits have replaced electromechanical devices in controlling appliances and machinery. It is often easier and cheaper to use a standard microcontroller and write a computer program to carry out a control function than to design an equivalent mechanical control function. The IBM Selective Sequence Electronic Calculator (SSEC) was an electromechanical computer built by IBM. Its design was started in late 1944, and it operated from January 1948 to 1952. It had many of the features of a stored-program computer and was the first operational machine able to treat its instructions as data, but it was not fully electronic. Although the SSEC proved useful for several high-profile applications it soon became obsolete. As the last large electromechanical computer ever built, its greatest success was the publicity it provided for IBM. Applications
The first application of the SSEC was calculating the positions of the moon and planets, known as Ephemeris. Each position of the moon required about 11,000 additions, 9,000 multiplications, and 2,000 table look-ups, which took the SSEC about seven minutes. This application used the machine for about six months; by then other users were lined up to keep the machine busy. It has sometimes been said that the SSEC produced the moon-position tables that were later used for plotting the course of the 1969 Apollo flight to the moon. Records closer to 1969 suggest, however, that while there was a relationship, it was most likely less immediate.
Thus, Mulholland and Devine (1968), working at NASA Jet Propulsion Laboratory, reported  that the JPL Ephemeris Tape System was “used for virtually all computations of spacecraft trajectories in the US space program”, and that it had, as its current lunar ephemeris, an evaluation of the Improved Lunar Ephemeris incorporating a number of corrections: sources are named as ‘The Improved Lunar Ephemeris’ (documentation which was the report of the Eckert computations carried out by the SSEC, complete with lunar position results from 1952–1971), with corrections as described by Eckert et al. (1966), and in the Supplement to the AE 1968. Taken together, the corrections thus referenced modify practically every individual element of the lunar computations, and thus the space program appears to have been using lunar data generated by a modified and corrected derivative of the computational procedure pioneered using the SSEC, rather than the directly resulting tables themselves. The first paying customer was General Electric.
The SSEC was also used for calculations by the U.S. Atomic Energy Commission for the NEPA project to power an airplane with a nuclear reactor. Robert D. Richtmyer of Los Alamos National Laboratory used the SSEC for some of the first large-scale applications of the Monte Carlo method. Llewellyn Thomas solved problems with stability of laminar flow, programmed by Donald A. Quarles, Jr. and Phyllis K. Brown. In 1949, Cuthbert Hurd was hired (also after a visit to the SSEC) and started a department of applied science; the operation of SSEC was eventually put into that organization. EDSAC
Electronic Delay Storage Automatic Calculator (EDSAC) was an early British computer. The machine, having been inspired by John von Neumann’s seminal First Draft of a Report on the EDVAC, was constructed by Maurice Wilkes and his team at the University of Cambridge Mathematical Laboratory in England. EDSAC was the first complete and fully operation regular stored-program electronic digital stored program computer. Later the project was supported by J. Lyons & Co. Ltd., a British firm, who were rewarded with the first commercially applied computer, LEO I, based on the EDSAC design. EDSAC ran its first programs on 6 May 1949, when it calculated a table of squares and a list of prime numbers. Applications of EDSAC
In 1950, Dr. M. V. Wilkes and Wheeler used EDSAC to solve a differential equation relating to gene frequencies in a paper by Ronald Fisher. This represents the first use of a computer to a problem in the field of biology. In 1951, Miller and Wheeler used the machine to discover a 79-digit prime—the largest known at the time. In 1952, A.S. Douglas developed OXO, a version of noughts and crosses (tic-tac-toe) for the EDSAC, with graphical output to a cathode ray tube. This may well have been the world’s first video game. In the 1960s, EDSAC was used to gather numerical evidence about solutions to elliptic curves, which led to the Birch and Swinnerton-Dyer conjecture. Further developments
EDSAC’s successor, EDSAC 2, was commissioned in 1958.
In 1961, an EDSAC 2 version of Autocode, an ALGOL-like high-level programming language for scientists and engineers, was developed by David Hartley. In the mid-1960s, a successor to the EDSAC 2 was planned, but the move was instead made to the Titan, a prototype Atlas 2—the latter having been developed from the Atlas Computer of the University of Manchester, Ferranti, and Plessey. 1945: EDVAC
John von Neumann (1903-1957), a mathematician and physicist at the Institute for Advanced Study in Princeton, played a key role in the development of the Electronic Discrete Variable Automatic Computer (EDVAC). The EDVAC was a successor to the ENIAC, and it had been designed to hopefully correct the weaknesses and problems of its predecessor. The EDVAC had a memory, which held the stored information and data. It was this stored memory that allowed for the EDVAC to be stopped and resumed at various times. The EDVAC also had a central processing unit (CPU), which can be found in many modern computers.
Plankalkul (“Plan Calculus”), developed by Konrad Zuse, was the first real programming language. Plankalkul made use of structured data, in which the records in the database was, a mixture of alphabetic and numeric data. It also used conditional statements, which modified the execution of a program. However, Plankalkul was not generally known outside of Germany.
Transistors were first developed in 1947 by Bell Telephone laboratories. They replaced vacuum tubes, which were big, bulky, costly, and unreliable. Transistors are most often used to regulate the flow of an electrical current and to switch electricity on and off.
The Selective Sequence Electronic Calculator (SSEC) was developed by IBM. It occupied space 25 feet by 40 feet and used punch cards, punched tape, vacuum tubes, and relays. It could do 50 multiplications per second, but it was not successful because of its high cost. 1949: EDSAC
Maurice Wilkes was a mathematician and a physicist at Cambridge University in 1959 when, inspired by the creation of EDVAC, he designed the Electronic Delay Storage Automatic Calculator (EDSAC). The EDSAC was the first practical stored-program computer. The EDSAC was humongous (it was smaller than the ENIAC though) and it contained 3000 tubes and used up 30 kilowatts of electric power.