Chapter 14 ( History of computers ) Flashcards
(24 cards)
Built the mechanical calculators using pegged wheels that could perform the four basic arithmetic function of addition, subtraction, multiplication, and division
17th century two mathematicians, Blaise Pascal and Gottfried Leibniz
designed an analytical
engine that performed general calculations automatically.
1842 Charles Babbage
designed a tabulating machine to record census data
1890 Herman Hollerith
designed and built the rst electronic digital computer.
1939 John Atansoff and Clifford Berry
built the frst ully operational working computer, called Colossus, which was designed to crack encrypted German military codes.
December 1943 the British
designed to crack encrypted German military codes.
Colossus
first general-purpose modern computer was developed in
1944 at Harvard University.
Meaning of ASCC
Automatic Sequence Controlled Calculator (ASCC)
known simply as the Mark I. It was an electromechanical device that was exceedingly slow and was prone to mal unction.
Automatic Sequence Controlled Calculator (ASCC),
first general-purpose electronic computer was developed in
1946 at the University o Pennsylvania by J. Presper Eckert and John Mauchly at a cost o $500,000.
This computer contained more than 18,000 vacuum tubes that ailed at an average rate o one every 7 minutes
ENIAC (Electronic Numerical Integrator and Calculator),
developed the transistor.
In 1948 scientists led by William Shockley at the Bell Telephone Laboratories
an electronic switch that alternately allows or does not allow electronic signals to pass.
Transistor
first commercially success ul general- purpose, stored program electronic digital computer.
UNIVersal Automatic Computer), which appeared in 1951
First-generation computers were
vacuum tube devices (1939–1958)
Second-generation computers, which became generally available in about
1958, were based on individually packaged transistors.
Third-generation computers used
Integrated circuits (ICs),
Third-generation computers were introduced in
1964
The microprocessor was developed in
1971 by Ted Ho o Intel Corporation.
The Fourth generation o computers, which first appeared in
1975
an extension o the third generation and incorporated large-scale integration (LSI); this has now been replaced by very large-scale integration (VLSI), which places millions o circuit elements on a chip that measures less than 1 cm.
Fourth Generation of computers
refers to any general-purpose, stored-program electronic digital computer.
Computer
refers to a continuously varying quantity
Analog
uses only two values that vary discretely through coding.
Digital system
