COMPUTER FULL NOTES_1_.pdf

1. INTRODUCTION TO COMPUTERS 1.1. A computer; A computer is an electronic device, operating under the control of instructions stored in its own memory, that can be programmed to accept data (input), process it into useful information (output), and store it in a secondary storage device (store) for safekeeping or future use. Or It is an electronic device that converts raw data into meaningful information. 1.2. CHARACTERISTICS OF MODERN COMPUTERS 1. Speed Computers are quite fast in their operation in that their speed is measured in Millions of Instructions Per Second (MIPS) or Megahertz (MHz) Inside the computer's system unit, the processing occurs through electronic circuits. Data and program instructions travel through these circuits at speeds close to the speed of light. Many computers process billions or trillions of operations in a single second. NB: Processing involves computing (adding, subtracting, multiplying, dividing), sorting, organizing, formatting, checking spelling and grammar, charting, displaying pictures, recording audio clips, playing music, and showing a movie. 2. Accuracy Computers are known to be accurate. They can process large amounts of data and generate error- free results, provided the data entered is correct. They hardly make any mistake. They are capable of detecting and correcting any mistakes made. It follows therefore, that if wrong data is fed into the computer, the resulting output will be incorrect. Hence the saying; Garbage In Garbage Out (G