ters. For all their apparent complexity, digital computers are basically simple machines. Every operation they perform, from navigating a spacecraft to playing a game of chess, is based on one key operation--determining whether certain switches, called gates, are open or closed. The real power of a computer lies in the speed with which it checks these switches--anywhere from 1million to 4 billion times, or cycles, per second. A computer can recognize only two states in each of its millions of circuit switches--on or off, or high voltage or low voltage. By assigning binary numbers to these states--1 for on and 0 for off, for example-and linking many switches together, a computer can represent any type of data--from numbers to letters to musical notes. This process is called digitization. Imagine that a computer is checking only one switch at a time. If the switch is on, it symbolizes one operation, letter, or number; if the switch is off it represents another. When switches are linked together as a unit, the computer can recognize more data in each cycle. For example, if a computer checks two switches at once it can recognize any of four pieces of data--one represented by the combination off-off; one by off-on; one by on-off; and one by on-on. The more switches a computer checks in each cycle, the more data it can recognize at one time and the faster it can operate. Below are some common groupings of switches (each switch is called a binary digit, or bit) and the number of discrete units of data that they can symbolize: 4 bits=a nibble (16 pieces of data); 8 bits=a byte (256 pieces of data); 16 bits=a word (65,536 pieces of data). 32 bits=a double word (4,294,967,296 pieces of data).A byte is the basic unit of data storage because all characters, numbers,...
