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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:
once a year
News:
When
Cambridge joined the computer age
Video:
ENIAC
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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