1. Data Processing Lesson 3

2. 3-1 The History of Computers 3-2 The Earliest Computing Devices 1. Abacus 2. Napier’s Bones 3. Oughtred’s slide rule 4. Pascal’s Calculator 5. Leibnir’s Calculator 6. Babbage’s analytical Engine 7. Hollerith’s Punched-card Machine

3. 3-1 History of Computers Historical records will tell us that man has invented three types of devices to assist him in calculating and processing data. They are: Manual mechanical Eletromechanical Electronic

4. Manual-mechanical : A simple mechanism powered by hand Abacus Slide rule Electromechanical: It is usually powered by an electric motor and uses switches and relays. Household electrical appliances Calculators Punched cards

5. Electronic : a device which has its principal components circuit boards, transistors or silicon chips and the like Modern digital computer

6. 3-2 The Earliest Computing Devices Abacus

7. 3-2 The Earliest Computing Devices Napier’s Bones

8. 3-2 The Earliest Computing Devices 3. Oughtred’s Slide Rule

9. 3-2 The Earliest Computing Devices 4. Pascal’s Calculator

10. 3-2 The Earliest Computing Devices 5. Leibniz’s Calculator

11. 3-2 The Earliest Computing Devices 6. Babbage’s Analytical Calculator

12. 3-2 The Earliest Computing Devices 7.Hollerith’s Punched-card Machine