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ENIAC (Electronic Numerical
Integrator And Computer)
The
first all-electronic computer Common
clues:
Granddaddy of digital computers; 1940s computer; First electronic
computer; Digital dinosaur; Pioneer computer; Early
computer Crossword
puzzle frequency:
3 times a year News: The
Computer That Helped Defeat the Nazis Needs Your Aid Video:
ENIAC
Where
a calculator like the ENIAC today is equipped with 18,000 vacuum
tubes and weighs 30 tons, computers in the future may have only
1,000 vacuum tubes and perhaps weigh 1.5 tons
~
Popular Mechanics 1949
ENIAC,
short for Electronic Numerical Integrator And Computer, was the
first all-electronic computer designed to be Turing-complete,
capable of being reprogrammed by rewiring to solve a full range
of computing problems. It
was preceded in 1941 by the fully tape-programmable but still
mechanical Z3 designed by Konrad Zuse and by the all-electronic
rewire-to-reprogram but not fully general purpose British
Colossus computer. Both ENIAC and Colossus used thermionic
valves, that is, vacuum tubes, while Z3 used mechanical relays.
The requirement to rewire to reprogram ENIAC was removed in 1948.
ENIAC
was developed and built by the U.S. Army for their Ballistics
Research Laboratory with the purpose of calculating ballistic
firing tables. ENIAC was conceived of and designed by J. Presper
Eckert and John William Mauchly of the University of
Pennsylvania. The computer was commissioned on May 17, 1943 as
Project
PX,
constructed at the Moore School of Electrical Engineering from
mid-1944, and formally operational from February 1946 having cost
almost $500,000. It was then shut off on November 9, 1946 for a
refurbishment and a memory upgrade. ENIAC was unveiled on
February 14, 1946 at the University of Pennsylvania and was
transferred to the Aberdeen Proving Grounds, Maryland in 1947.
There, on July 29th of that year, it was turned on and would be
in continuous operation until 11:45 PM on October 2, 1955.
ENIAC
used ten-position ring counters to store digits. 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. 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 (Note: It was possible to connect several pairs
of accumulators simultaneously, so the peak speed of operation
was potentially much higher due to parallel
operation).
Physically ENIAC was a monster—it
contained 17,468 vacuum tubes, 7,200 crystal diodes, 1,500
relays, 70,000 resistors, 10,000 capacitors and around 5 million
hand-soldered joints. It weighed 30 short tons (27 t), was
roughly 2.4 m by 0.9 m by 30 m, took up 167 m² and consumed
160 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 accounting
machine, probably the IBM 405.
As of 2004, a chip of
silicon measuring 0.02 inches (0.5 mm) square holds the same
capacity as the ENIAC, which occupied a large room.
This
article is licensed under the GNU
Free Documentation License.
It uses material from the Wikipedia
article "ENIAC".
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