Hello There,br br In this tutorial, I am going to teach you about the followings;br br INTRODUCTION TO COMPUTERbr Evolution Of Computersbr (i) Mechanical Era (Dark Age)br (a) Abacus (3000 B.C.)br (b) Napier's Bones (1612 A.D.)br (c) Slide Rule (1622 A.D.)br (d) Pascaline or Pascal's Calculator (1642 A.D.)br (e) Leibniz's Calculator (1694 A.D.)br (f) Babbage's Difference and Analytical Engines (1822 and 1837 A.D.