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COMPUTER

20090239

ENG 204

GÜLŞEN HÜSEYİN

MUSTAFA DOLMACI

The history of computer science began long before the
modern discipline of computer science that emerged in the
20th century, and hinted at in the centuries prior
progression, from mechanical inventions
and mathematical theories towards the modern concepts
and machines, formed a major academic field

 The earliest known tool for use in computation was
the abacus, developed in period 2700–2300 BC
in Sumer. The Sumerians' abacus consisted of a table
of successive columns which delimited the successive
orders of magnitude of their sexagesimal number
system.[2] Its original style of usage was by lines drawn
in sand with pebbles. Abaci of a more modern design
are still used as calculation tools today.

Binary logic
 In 1703, Gottfried Leibnitz developed logic in a formal,
mathematical sense with his writings on the binary
numeral system. In his system, the ones and zeros also
represent true and false values or onand off states. But
it took more than a century before George
Boole published his Boolean algebra in 1854 with a
complete system that allowed computational processes
to be mathematically modeled.

 By this time, the first mechanical devices driven by a
binary pattern had been invented. The industrial
revolution had driven forward the mechanization of
many tasks, and this included weaving. Punched
cards controlled Joseph Marie Jacquard's loom in 1801,
where a hole punched in the card indicated a
binary one and an unpunched spot indicated a
binary zero. Jacquard's loom was far from being a
computer, but it did illustrate that machines could be
driven by binary systems.

Birth of computer science
 Before the 1920s, computers (sometimes computors)
were human clerks that performed computations. They
were usually under the lead of a physicist. Many
thousands of computers were employed in commerce,
government, and research establishments. Most of
these computers were women, and they were known to
have a degree in calculus. Some performed
astronomical calculations for calendars.

 After the 1920s, the expression computing
machine referred to any machine that performed the
work of a human computer, especially those in
accordance with effective methods of the Church-Turing
thesis. The thesis states that a mathematical method is
effective if it could be set out as a list of instructions able
to be followed by a human clerk with paper and pencil,
for as long as necessary, and without ingenuity or
insight.

 Machines that computed with continuous values
became known as the analog kind. They used
machinery that represented continuous numeric
quantities, like the angle of a shaft rotation or difference
in electrical potential.

Wiener and Cybernetics
 From experiments with anti-aircraft systems that
interpreted radar images to detect enemy
planes,Norbert Wiener coined the term cybernetics from
the Greek word for "steersman." He published
"Cybernetics" in 1948, which influenced artificial
intelligence. Wiener also compared computation,
computing machinery, memory devices, and other
cognitive similarities with his analysis of brain waves.

 The first actual computer bug was a moth. It was stuck
in between the relays on the Harvard Mark II.[1] While
the invention of the term 'bug' is often but erroneously
attributed to Grace Hopper, a future rear admiral in the
U.S. Navy, who supposedly logged the "bug" on
September 9, 1945, most other accounts conflict at least
with these details. According to these accounts, the
actual date was September 9, 1947 when operators filed
this 'incident' — along with the insect and the notation
"First actual case of bug being found.

 REFERENCES

http://en.wikipedia.org/wiki/History_of_computer_science

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