2. 1 Early Counting Devices 6 5 4 3 2 Fingers: As old as man, but limited in scope Fingers: As old as man, but limited in scope Pebble or Stones: Small smooth stones, but bulky in nature Pebble or Stones: Small smooth stones, but bulky in nature Cowries: Used as currency, but useful in counting numbers Wooden sticks: Local sticks, but replaced by notch sticks Wooden sticks: Local sticks, but replaced by notch sticks Counting boxes: Labelled boxes mostly used in businesses Counters: Flat plastics with two different colors

3. Mechanical Counting Devices Napier’s Bones Abacus Slide Rule 2 1 3

4. ELECTROMECHANICAL COUNTING DEVICES Pascaline An adding machine developed by Blaise Pascal in 1642 Leibniz First true calculator invented by Gottfried Leibniz in 1673 Analytical engine A general-purpose programmable machine designed by Charles Babbage Jacquard loom A textile production machine developed by Joseph Jacquard in 1804 4 1 3 2

5. MODERN COMPUTERS Popular stored-program computers invented in the early years. 1 2 3 4 5 ENIAC (Electronic Numerical Integrator and Computer) First general-purpose programmable computer developed in 1945. Manchester Mark 1 A computer designed and built at Victoria University, England in 1949. EDSAC (Electronic Delay Storage Automatic Calculator Inspired by Neumann’s report and built by Maurice Wilkes and team in 1949. EDVAC (Electronic Discrete Variable Automatic Computer) Improved version of ENIAC developed at More School of Engineering in 1951. UNIVAC (Universal Automatic Computer) First commercial computer developed by Presper Eckert and John Mauchly in 1951.

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7. Classification of Computers by Generation

8. Classification of Computers by Size

9. Special-Purpose General-Purpose

11. Computer System