The EDVAC as installed in Building 328 at the Ballistics Research Laboratory.

EDVAC (Electronic Discrete Variable Automatic Computer) was one of the earliest electronic computers. Electronics refers to the flow of charge (moving Electrons through Nonmetal conductors (mainly Semiconductors, whereas electrical A computer is a Machine that manipulates data according to a list of instructions. Unlike its predecessor the ENIAC, it was binary rather than decimal, and was a stored program machine. ENIAC, short for Electronic Numerical Integrator And Computer, was the first general-purpose electronic Computer. The binary numeral system, or base-2 number system, is a Numeral system that represents numeric values using two symbols usually 0 and 1. The decimal ( base ten or occasionally denary) Numeral system has ten as its base. The von Neumann architecture is a design model for a stored-program Digital computer that uses a processing unit and a single separate storage structure

Project origin and plan

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. John William Mauchly ( August 30 1907 &ndash January 8 1980) was an American Physicist who along with J John Adam Presper "Pres" Eckert Jr ( April 9, 1919 – June 3, 1995) was an American electrical engineer and ENIAC, short for Electronic Numerical Integrator And Computer, was the first general-purpose electronic Computer. 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. Genesis in radar The basic concept of the delay line originated with World War II Radar research as a system to reduce clutter from reflections from the ground ^[1] 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. The United States Army is a military organization whose primary mission is to "provide necessary forces and capabilities. The United States Army Ballistic Research Laboratory (BRL at Aberdeen Proving Ground, Maryland was the center for the army's research efforts in interior Aberdeen Proving Ground (APG is a United States Army facility located near Aberdeen Maryland (in Harford County) The University of Pennsylvania (also known as Penn) is a private University located in Philadelphia, Pennsylvania, USA. Moore School of Electrical Engineering at the University of Pennsylvania came into existence as a result of an endowment from Alfred Fitler Moore on June 4, 1923 Eckert and Mauchly and the other ENIAC designers were joined by John von Neumann in a consulting role; von Neumann summarized and elaborated upon logical design developments in his 1945 First Draft of a Report on the EDVAC. The First Draft of a Report on the EDVAC (commonly shortened to First Draft) was an incomplete 101-page document written by John ^[2]

A contract to build the new computer was signed in April 1946 with an initial budget of US$100,000. The United States dollar ( sign: $; code: USD) is the unit of Currency of the United States; it has also been 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, five times the initial estimate.

Technical description

The EDVAC was a binary serial computer with automatic addition, subtraction, multiplication, programmed division and automatic checking with an ultrasonic serial memory^[1] capacity of 1,000 44-bit words (later set to 1,024 words, thus giving a memory, in modern terms, of 5. A serial computer is typified by internally operating on one Bit or digit for each clock cycle. Genesis in radar The basic concept of the delay line originated with World War II Radar research as a system to reduce clutter from reflections from the ground In Computing, " word " is a term for the natural unit of data used by a particular computer design 5 kilobytes). A kilobyte (derived from the SI prefix Kilo -, meaning 1000 is a unit of Information or Computer storage equal to either 1024

Physically, the computer comprised the following components:

• a magnetic tape reader-recorder (Wilkes 1956:36^[1] describes this as a wire recorder. Magnetic tape is a medium for Magnetic recording generally consisting of a thin magnetizable coating on a long and narrow strip of Plastic. Wire recording is a type of analogue Audio storage in which the recording is made onto thin steel or stainless steel Wire. )
• a control unit with an oscilloscope
• a dispatcher unit to receive instructions from the control and memory and direct them to other units
• a computational unit to perform arithmetic operations on a pair of numbers at a time and send the result to memory after checking on a duplicate unit
• a timer
• a dual memory unit consisting of two sets of 64 mercury acoustic delay lines of eight words capacity on each line
• three temporary tanks each holding a single word^[1]

EDVAC's addition time was 864 microseconds and its multiplication time was 2900 microseconds (2. An oscilloscope (commonly abbreviated to scope or O-scope) is a type of Electronic test equipment that allows signal Voltages to be viewed Mercury (ˈmɜrkjʊri also called quicksilver or hydrargyrum, is a Chemical element with the symbol Hg ( Latinized hydrargyrum To help compare Orders of magnitude of different Times this page lists times between 10&minus6 seconds and 10&minus5 seconds (1 micro 9 milliseconds).

The computer had almost 6,000 vacuum tubes and 12,000 diodes, and consumed 56 kW of power. This article is about the electronic device not an evacuated pipe used for experiments in Free-fall. Dioden2jpg|thumb|right|150px|Figure 2 Various semiconductor diodes The watt (symbol W) is the SI derived unit of power, equal to one Joule of energy per Second. It covered 490 ft² (45. The square foot is an Imperial unit / US customary unit (non- SI non- metric) of Area, used mainly in the United States 5 m²) of floor space and weighed 17,300 lb (7,850 kg). M^2 redirects here For other uses see M². CM2 redirects here The full complement of operating personnel was thirty people for each eight-hour shift.

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. A patent is a set of Exclusive rights granted by a State to an inventor or his assignee for a fixed period of time in exchange for a disclosure of an

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. Drum memory is a magnetic Data storage device and was an early form of Computer memory widely used in the 1950s and into the 1960s invented by Gustav Tauschek In Computing, floating point describes a system for numerical representation in which a string of digits (or Bits represents a Real number.

EDVAC ran until 1961 when it was replaced by BRLESC. The BRLESC I ( B allistic R esearch L aboratories E lectronic S cientific C omputer was a first-generation electronic computer During its operational life it proved to be reliable and productive for its time.

References

1. ^ ^{a b c d} Wilkes, M. V. (1956). Automatic Digital Computers. New York: John Wiley & Sons, 305 pages. QA76. W5 1956.  
2. ^ "First Draft of a Report on the EDVAC" (PDF format) by John von Neumann, Contract No. W-670-ORD-4926, between the United States Army Ordnance Department and the University of Pennsylvania. The University of Pennsylvania (also known as Penn) is a private University located in Philadelphia, Pennsylvania, USA. Moore School of Electrical Engineering, University of Pennsylvania, June 30, 1945. Moore School of Electrical Engineering at the University of Pennsylvania came into existence as a result of an endowment from Alfred Fitler Moore on June 4, 1923 Events 350 - Roman usurper Nepotianus, of the Constantinian dynasty, is defeated and killed by troops of the Usurper Year 1945 ( MCMXLV) was a Common year starting on Monday (link will display the full calendar The report is also available in Stern, Nancy (1981). From ENIAC to UNIVAC: An Appraisal of the Eckert-Mauchly Computers. Digital Press.  .