Computers & Calculating Devices

History and Evolution of Computers

Computer is an electronic device created for calculation purpose. But before the computer there were many more calculating devices as explained below:

Abacus

• History of computers began with abacus

• Invented almost 5,000 years ago (1,100 BCE)

• Used for addition, subtraction, multiplication and division

• Is a wooden tool with wires and beads attached to it

Napier’s Bones

• Invented in 1617 by John Napier

• Apart from the 4 basic calculations, it also finds square roots

• Consists of a set of rectangular rods made up of carved bones

Pascaline

• Invented in 1642 by Blaise Pascal

• First mechanical device used for calculations

• Performs addition and subtraction

• It consists of wheels and gears which rotate to perform calculations

Difference Engine

• Designed by Charles Babbage in 1822

• Designed to perform polynomial functions

• Expected to be 8 ft tall and had about 25,000 different parts

Analytical Engine

• Built by Charles Babbage in 1844

• Has 2 input streams, 3 output streams, a processing unit and memory

• Was first machine to have a set of programming instructions

Punched Card Machine

• Invented by Herman Hollerith

• Unlike earlier devices, this machine had facility to store data

E N I A C

• Designed by Mauchly and Presper Eckert

• Stands for Electronic Numerical Integrator and Computer

• Performs 5,000 instructions per second

Von Neuman

• Invented by John Von Neuman

• Is a stored program concept

• Programs and data are stored in separate storage units called memories

Mark I

• Invented by Howard Aiken in 1944

• Based on Charles Babbage’s Analytical Engine

• Programmed to handle logarithms and trigonometric functions

• For input and output, it uses paper tape readers, card readers, card punch and typewriters

Generations of Computer

Types of computers

• Supercomputer

• Mainframe Computer

• Mini Computer

• Workstation Computer

• Personal Computer (PC)

• Server Computer

• Analog Computer

• Digital Computer

• Hybrid Computer

• Tablets and Smartphones

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