Bővebb ismertető
PREFACE
This book is intended to help you understand what computers are, what they do, and how they do it. The entries cover a wide range of topics, including hardware, software, programming concepts and languages, operating systems, electronics, logic circuits, history of computers, and specific models of personal computers. The lists of terms by categories at the front of the book will help you find entries that relate to a particular topic.
Thousands of software packages are now available that allow computers to perform a wide variety of tasks, and new packages are constantly being introduced. We discuss some popular software packages (for example, we show how to set up a simple spreadsheet using the program Lotus 1-2-3). We also describe some of the general tasks that software packages perform and explain much of the terminology that appears in software advertisements. However, it would be impossible to include a listing for every worthwhile item of software or hardware. Instead, we have chosen to concentrate on those items that, in our judgment, have become especially common or were unusually innovative.
This book will also help you if you are interested in writing your own programs. We provide articles on nearly all of the programming languages in widespread use today, with sample programs in Ada, ALGOL, APL, BASIC, C, COBOL, FORTRAN, LISP, LOGO, Pascal, PL/I, and Prolog. Several features of the languages BASIC and Pascal are described in more detail. In addition, we include ready-to-run programs illustrating several important algorithms (selection sort. Quicksort, etc.) and quick-reference tables of information often used in programming (ASCII characters, hexadecimal numbers, Epson printer control codes).
We also include descriptions of the electronic components and logic circuits of which computers are made. For example, we describe how a transistor works and illustrate how a machine made with transistors can perform arithmetic calculations. You do not need to know much about how computers work in order to use one, but a knowledge of their inner workings can make them less mysterious and help you appreciate their capabilities.
The field of computers changes very rapidly, making this new edition of the book necessary. For example, desktop publishing