An introductory level text for high school students, this book elucidates the step-by-step procedures used to solve problems and demonstrates the simplicity with which one can read and write computer programmes using BASIC language. It explains how a computer works, using an elementary model of the computer. All programmes are worked out on the IBM PC and involve a minimum of mathematics. This new edition is thoroughly revised and updated to incorporate recent developments in the field. It also contains a large number of worked-out examples and exercises with solutions to assist self-study. It can be used by all interested beginners and laymen as well.