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Network Security 101Session 1

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Early Mechanical Computers

Abacus Pascaline machine

Napier’s Bones

Stepped Reckoner

Arithmometer

Punch cards

Babbage’s Difference Engine

B.C.B.C. 16171617 16421642 16731673 18201820 18011801 18321832

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An Abacus (BC)

A mechanical device used for counting. Addition, subtraction,

multiplication and division can be performed on a standard abacus.

Using the abacus is still taught in Asian schools and still used by

shopkeepers in Asia and “Chinatowns” in the USA.

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Napier’s Bones (1617)

of logarithms and calculate based on relative

position of the scales and when bound together

created the first slide rule.

John Napier’s bones

work on the principal