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ENIAC

ENIAC, short for Electronic Numerical Integrator and Computer, was the first large-scale, electronic, digital computer capable of being reprogrammed to solve a full range of computing problems, although earlier computers had been built with some of these properties. ENIAC was designed and built to calculate artillery Artillery

Historically, artillery refers to any engine used for the discharge of projectile [i]s during war [i] ... 

 firing tables for the U.S. Army United States Army

The United States Army is the largest branch of the United States armed forces [i] ... 

's Ballistics Research Laboratory. The first problems run on the ENIAC however, were related to the design of the hydrogen bomb Nuclear weapon

A nuclear weapon derives its destructive force from nuclear reaction [i]s of fission [i] ... 

. The contract was signed on June 5, 1943 and Project PX was constructed by Penn's University of Pennsylvania

The University of Pennsylvania is a private [i], nonsectarian research university loc... 

 Moore School of Electrical Engineering from July, 1943.

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Timeline

1943   The United States Army United States Army

The United States Army is the largest branch of the United States armed forces [i] ... 

 contracts with the University of Pennsylvania University of Pennsylvania

The University of Pennsylvania is a private [i], nonsectarian research university loc... 

's Moore School to develop the ENIAC.

1945   Assembly of the world's first general purpose electronic computer, the Electronic Numerical Integrator and Computer (ENIAC), is completed. It covers 1800 feet of floor spa The first set of calculations is run on the computer.

1946   ENIAC (for "Electronic Numerical Integrator and Computer"), the first general-purpose electronic computer Computer

A computer is a machine [i] for manipulating data [i] according to a list of instructions [i] ... 

, is unveiled at the University of Pennsylvania University of Pennsylvania

The University of Pennsylvania is a private [i], nonsectarian research university loc... 

1947   After being shut off on November 9, 1946 for a refurbishment, ENIAC, one of the world's first digital computer Computer

A computer is a machine [i] for manipulating data [i] according to a list of instructions [i] ... 

s, is turned on after a memory upgrade. It will remain in continuous operation until October 2, 1955.



Encyclopedia


ENIAC, short for Electronic Numerical Integrator and Computer, was the first large-scale, electronic, digital computer capable of being reprogrammed to solve a full range of computing problems, although earlier computers had been built with some of these properties. ENIAC was designed and built to calculate artillery Artillery

Historically, artillery refers to any engine used for the discharge of projectile [i]s during war [i] ... 

 firing tables for the U.S. Army United States Army

The United States Army is the largest branch of the United States armed forces [i] ... 

's Ballistics Research Laboratory. The first problems run on the ENIAC however, were related to the design of the hydrogen bomb Nuclear weapon

A nuclear weapon derives its destructive force from nuclear reaction [i]s of fission [i] ... 

.

The contract was signed on June 5, 1943 and Project PX was constructed by Penn's University of Pennsylvania

The University of Pennsylvania is a private [i], nonsectarian research university loc... 

 Moore School of Electrical Engineering from July, 1943. It was unveiled on February 15, 1946 at the University of Pennsylvania, having cost almost $500,000. ENIAC was shut down on November 9, 1946 for a refurbishment and a memory upgrade, and was transferred to the Aberdeen Proving Ground, Maryland Maryland

Maryland , is a Mid-Atlantic [i] state [i] located on the East Coast [i] ... 

 in 1947. There, on July 29 of that year, it was turned on and would be in continuous operation until 11:45 p.m. on October 2, 1955.

ENIAC was conceived and designed by John William Mauchly and J. Presper Eckert of the University of Pennsylvania University of Pennsylvania

The University of Pennsylvania is a private [i], nonsectarian research university loc... 

. The patent for the ENIAC, granted in 1964, was voided by the 1973 decision of the landmark federal court case Honeywell v. Sperry Rand, putting the invention of the electronic digital computer in the public domain Public domain

Public domain comprises the body of knowledge [i] and innovation [i] in relation to which no person or ... 

.


Description

Physically, ENIAC was massive. It contained 17,468 vacuum tube Vacuum tube

In electronics [i], a vacuum tube or valve is a device generally used to amplify [i], ... 

s, 7,200 crystal diode Diode

In electronics [i], a diode is a component [i] that restricts the direction of mov... 

s, 1,500 relay Relay

A relay is an electrical switch [i] that opens and closes under control of another electrical circuit. ... 

s, 70,000 resistor Resistor

|- align = "center"
|
|width = "25"|
... 

s, 10,000 capacitor Capacitor

A capacitor is an electric [i]al device that can store energy [i] in the electric field [i] between a pair of ... 

s and around 5 million hand-solder Solder

A solder is a fusible [i] metal alloy [i], with a melting point or melting range below 450 ... 

ed joints. It weighed 30 short tons , was roughly 8 feet by 3 feet by 100 feet , took up 1800 square feet , and consumed 150 kW of power. Input was possible from an IBM card reader, while an IBM card punch was used for output. These cards could be used to produce printed output offline using an IBM IBM

company_name = International Business Machines Corporation |
... 

 accounting machine, probably the IBM 405 IBM 407

The IBM 407 Accounting Machine, introduced in 1949, was the culmination of a long line of IBM [i] tabulating machines [i] ... 

.

ENIAC used ten-position ring counters to store digits; each digit used 36 tubes, 10 of which were the dual triodes making up the flip-flop Flip-flop

In footwear [i] and fashion [i], flip-flops are a kind of flat, backless sandal [i] that consist ... 

s of the ring counter. Arithmetic was performed by "counting" pulses with the ring counters and generating carry pulses if the counter "wrapped around", the idea being to emulate in electronics the operation of the digit wheels of a mechanical adding machine Adding machine

An adding machine is a type of calculator [i], usually specialized for bookkeeping [i] calculations.
... 

. ENIAC had twenty ten-digit signed accumulators and could perform 5,000 simple addition or subtraction operations between any selected pair of them every second . It was possible to wire the carry of one accumulator into another to perform double precision arithmetic but the accumulator carry circuit timing prevented the wiring of three or more for higher precision. The ENIAC used four of the accumulators controlled by a special Multiplier unit and could perform 385 multiplication operations per second. The ENIAC used five of the accumulators controlled by a special Divider/Square-Rooter unit and could perform forty division operations per second or three square root Square root

In mathematics [i], a square root of a number x is a number whose square [i] is x. ... 

 operations per second. The other nine units in ENIAC were the Initiating Unit , the Cycling Unit , the Master Programmer , the Reader , the Printer , the Constant Transmitter, and three Function Tables. Design engineers included Bob Shaw , Chuan Chu , Kite Sharpless , Arthur Burks , Harry Huskey , and Jack Davis .


The reference by Rojas and Hashagen gives more details about the times for operations, which differ somewhat from those above. The basic clock cycle was 200 microseconds, or 5,000 cycles per second for operations on the 10-digit numbers. In one of these cycles, ENIAC could write a number to a register, read a number from a register, or add/subtract two numbers. A multiplication of a 10-digit number by a d-digit number took d+4 cycles, so a 10- by 10-digit multiplication took 14 cycles, or 2800 microseconds—a rate of 357 per second. If one of the numbers had fewer than 10 digits, the operation was faster. Division and square roots took 13 cycles, where d is the number of digits in the result . So a division or square root took up to 143 cycles, or 28,600 microseconds—a rate of 35 per second. If the result had fewer than ten digits, it was obtained faster.

Reliability

ENIAC used common octal-base Tube socket

Tube sockets were ubiquitous in early electronic equipment to allow vacuum tube [i]s to be easily remov ... 

 radio tubes of the day; the decimal accumulators were made of 6SN7 6SN7

6SN7 is a dual triode [i] vacuum tube [i], on an 8 pin octal base [i].... 

 flip-flops Flip-flop

In footwear [i] and fashion [i], flip-flops are a kind of flat, backless sandal [i] that consist ... 

, while 6L7s, 6SJ7s, 6SA7s and 6AC7s were used in logic functions. Numerous 6L6 6L6

6L6 is the designator for a vacuum tube [i] introduced by Radio Corporation of America RCA [i] United States [i] ... 

s and 6V6 6V6

6V6 is the designator for a vacuum tube introduced by Radio Corporation of America RCA [i] United States ... 

s served as line drivers to drive pulses through cables between rack assemblies.


Some electronics experts predicted that tube failures would occur so frequently that the machine would never be useful. This prediction turned out to be partially correct: several tubes burned out almost every day, leaving it nonfunctional about half the time. Special high-reliability tubes were not available until 1948. Most of these failures, however, occurred during the warm-up and cool-down periods, when the tube heaters and cathodes were under the most thermal stress. By the simple expedient of never turning the machine off, the engineers reduced ENIAC's tube failures to the more acceptable rate of one tube every two days. According to a 1989 interview with Eckert the continuously failing tubes story was therefore mostly a myth: "We had a tube fail about every two days and we could locate the problem within 15 minutes."

In 1954, the longest continuous period of operation without a failure was 116 hours . This failure rate was remarkably low, and stands as a tribute to the precise engineering of ENIAC.


Programmability

The six women who did most of the programming of ENIAC by manipulating its switches and cables were inducted in 1997 into the Women in Technology International Hall of Fame . As they were called by each other in 1946, they were Kay McNulty Kathleen Antonelli

Kathleen "Kay" McNulty Mauchly Antonelli was one of the six original programmers of the ENIAC [i], the f ... 

, Betty Jennings, Betty Snyder, Marlyn Wescoff, Fran Bilas Frances Spence

Frances Spence was one of the original programmers for the ENIAC [i] computer.
... 

 and Ruth Lichterman.

Eckert and Mauchly took the experience they gained and founded the Eckert-Mauchly Computer Corporation, producing their first computer, BINAC, in 1949 before being acquired by Remington Rand Remington Rand

Remington Rand was an early American [i] computer [i] manufacturer, best known as the orig ... 

 in 1950 and renamed as their UNIVAC UNIVAC

UNIVAC serves as the catch-all name for the American [i] manufacturers of the lines of mai ... 

 division.

ENIAC was a one-of-a-kind design and was never repeated. The freeze on design in 1943 meant that the computer had a number of shortcomings which were not solved, notably the inability to store a program. But the ideas generated from the work and the impact it had on people such as John von Neumann John von Neumann

John von Neumann was an Austro-Hungarian [i] mathematician [i] and polymath [i] who ma ... 

 were profoundly influential in the development of later computers, initially EDVAC EDVAC

EDVAC was one of the earliest electronic [i] computer [i]s. ... 

, EDSAC EDSAC

EDSAC ' was an early British [i] computer [i] . ... 

 and SEAC.

A number of improvements were also made to ENIAC from 1948, including a primitive read-only stored programming mechanism using the Function Tables as program ROM Read-only memory

Read-only memory is a class of storage media used in computer [i]s and other electronic devices. ... 

, an idea proposed by John von Neumann John von Neumann

John von Neumann was an Austro-Hungarian [i] mathematician [i] and polymath [i] who ma ... 

. Three digits of one accumulator was used as the program counter, another accumulator was used as the main accumulator, and most of the other accumulators were just used for data memory. It was first demonstrated as a stored-program computer on September 16 1948, running a program by Adele Goldstine for John von Neumann. This modification reduced the speed of ENIAC by a factor of six, but as it also reduced the reprogramming time to hours instead of days, it was considered well worth the loss of performance. Early in 1952, a high speed shifter was added, which improved the speed for shifting by a factor of five. In July 1953, a 100-word expansion core memory Magnetic core memory

Magnetic core memory, or ferrite-core memory, is an early form of computer memory [i]. ... 

 was added to the system, using binary coded decimal, excess-3 number representation. To support this expansion memory, the ENIAC was equipped with a new Function Table selector, a memory address selector, pulse-shaping circuits, and three new orders were added to the programming mechanism.

Comparison with other early computers


Mechanical and electrical computing machines have been around since the 19th century, but the 1930s and 40s are considered the beginning of the modern computer era.
  • The American Atanasoff-Berry Computer Atanasoff-Berry Computer

    The Atanasoff-Berry Computer was the first electronic [i] digital [i] computing [i] device. ... 

      was thought by some to be the first electronic digital computer. It implemented binary computation with vacuum tubes Vacuum tube

    In electronics [i], a vacuum tube or valve is a device generally used to amplify [i], ... 

     but was not general purpose, being limited to solving systems of linear equations. It also did not exploit electronic computing speeds, being limited by an electromechanical memory and an input-output system that was intended to write intermediate results to paper cards.
  • The German Z3 was designed in 1941 by Konrad Zuse Konrad Zuse

    Konrad Zuse was a German [i] engineer [i] and computer pioneer.... 

    . It was the first general purpose, electromechanical computer. It was a digital computer using binary math, was Turing-complete and fully programmable by punched tape. Since the computer used relay Relay

    A relay is an electrical switch [i] that opens and closes under control of another electrical circuit. ... 

    s for all functions it was not electronic.
  • The British Colossus computer Colossus computer

    The Colossus machines were early computing devices used by British codebreaker [i]s to read encrypted Ge ... 

      was designed by Tommy Flowers. Colossus was digital, all-electronic, and could be reprogrammed by rewiring, but was not fully general purpose as it was not Turing-complete.
  • Howard Aiken Howard Aiken

    Howard Hathaway Aiken was a pioneer in computing [i], being the primary engineer behind IBM [i]'s Harvard Mark I [i] ... 

    's 1944 Harvard Mark I Harvard Mark I

    The IBM [i] ASCC, called the Mark I by Harvard University [i], was the first large-scale automatic ... 

     was programmed by punched tape and used relays.


The ABC, ENIAC and Colossus all used thermionic valves . ENIAC's registers performed decimal, rather than binary, arithmetic like the Z3 or the Atanasoff-Berry Computer.

Until 1948, ENIAC required rewiring to reprogram, like the Colossus. The idea of the stored-program Von Neumann architecture

[i] design model that uses a single [[computer storage|storage]... 

 computer with combined memory for program and data was conceived during the development of the ENIAC, but it was not implemented at that time because World War II priorities required the machine to be completed quickly, and it was realized that 20 storage locations for memory and programs would be much too small.

Priority

The Z3, Colossus and ENIAC were developed independently and in secret as part of each country's war effort in WWII World War II

World War II, or the Second World War, was a worldwide [i] conflict [i] fought betwe ... 

. The Z3 was destroyed by Allied bombing of Berlin in 1944. The Colossus machines were destroyed in 1945 on Winston Churchill Winston Churchill

Sir Winston Leonard Spencer-Churchill, KG [i], OM [i], CH [i] ... 

's orders and their existence remained classified until the 1970s, though knowledge of their capabilities remained among the UK staff and invited Americans. The ABC was abandoned at Iowa State University Iowa State University

Iowa State University is a public land-grant [i] and space-grant [i] ... 

, when John Atanasoff John Vincent Atanasoff

John Vincent Atanasoff was an American physicist [i] of Bulgarian [i] descent. ... 

 was called to Washington, DC Washington, D.C.

Washington, D.C. is the capital [i] city [i] of the United States of America [i]. ... 

 to do war research. ENIAC, by contrast, was put through its paces for the press in 1946, "and captured the world's imagination". For these reasons, histories of computing formerly mentioned only ENIAC and the Harvard Mark I from this period.

Trivia



The School of Engineering and Applied Science at the University of Pennsylvania University of Pennsylvania

The University of Pennsylvania is a private [i], nonsectarian research university loc... 

 has four of the original 40 panels of the ENIAC. The artifacts on display represent approximately 1/10th of its original size. The Smithsonian Smithsonian Institution

The Smithsonian Institution is an educational and research institute and associated museum [i] complex, ... 

 has 5 panels in the National Museum of American History National Museum of American History

The National Museum of American History is a museum [i] administered by the Smithsonian Institution [i] ... 

 in Washington D.C. The Computer History Museum Computer History Museum

The Computer History Museum is a museum [i] established in 1996, when the Boston Computer Museum s ... 

 in Mountain View, California has a single panel on display. The University of Michigan University of Michigan

The University of Michigan, Ann Arbor is a coeducational [i] public [i] research university [i] ... 

 in Ann Arbor has four panels, salvaged by Arthur Burks. The U.S. Army Ordnance Museum  also holds some of the ENIAC.

As of 2004 2004

2004 was a leap year starting on Thursday [i] of the Gregorian calendar [i].
... 

, a chip of silicon measuring 0.02 inches square holds the same capacity as the ENIAC, which occupied a large room.

See also

  • History of computing
  • Other early computers:
    • Atanasoff-Berry Computer Atanasoff-Berry Computer

      The Atanasoff-Berry Computer was the first electronic [i] digital [i] computing [i] device. ... 

    • Colossus computer Colossus computer

      The Colossus machines were early computing devices used by British codebreaker [i]s to read encrypted Ge ... 

    • CSIRAC CSIRAC

      CSIRAC, originally known as CSIR Mk I, was Australia [i]'s first digital computer [i], and the fif ... 

    • Harvard Mark I Harvard Mark I

      The IBM [i] ASCC, called the Mark I by Harvard University [i], was the first large-scale automatic ... 

    • Manchester Mark I
    • SSEC
    • Z3

References



  • H. H. Goldstine, A. Goldstine, The Electronic Numerical Integrator and Computer , 1946


  • J. Presper Eckert, The ENIAC


  • John W. Mauchly, The ENIAC


  • Arthur W. Burks, Alice R. Burks, The ENIAC: The First General-Purpose Electronic Computer


  • W. Barkley Fritz, The Women of ENIAC


  • J. Presper Eckert, John Mauchly, Outline of plans for development of electronic computers


  • Raúl Rojas and Ulf Hashagen, editors, The First Computers: History and Architectures, 2000, MIT Press, ISBN 0-262-18197-5.

Further reading

  • Mike Hally, Electronic Brains: Stories from the Dawn of the Computer Age, Joseph Henry Joseph Henry

    Joseph Henry was a Scottish [i]-American [i] scientist. ... 

     Press, 2005. ISBN 0-309-09630-8
  • Scott McCartney, ENIAC: The Triumphs and Tragedies of the World's First Computer. Walker & Co, 1999. ISBN 0-8027-1348-3.
  • Edmund C. Berkeley, GIANT BRAINS or machines that think. John Wiley & sons, inc., 1949. Chapter 7 Speed—5000 Additions a Second: Moore School's ENIAC
  • C.B. Tompkins and J.H Wakelin, High-Speed Computing Devices, McGraw-Hill, 1950.*

External links

  • chapter in Karl Kempf, Electronic Computers Within The Ordnance Corps, November 1961
  • , Martin H. Weik, Ordnance Ballistic Research Laboratories, 1961
  • at the University of Pennsylvania
  • Modern photographs of parts of the ENIAC
  • 60th anniversary news story
  • Transcript of a video interview with Eckert by David Allison for the National Museum of American History, Smithsonian Institution on February 2, 1988. An in-depth, technical discussion on the ENIAC, including the thought process behind the design.
  • from Ballistic Research Laboratories Report No. 971 December 1955,
  • issued in 1964 for ENIAC , also