electronic data and instruction

Data and instructions are represented electrically with a binary, or two state, numbering system. ASCII, EBCDIC and Unicode are binary coding schemes. Have you ever wondered why it is said that we live in a digital world? It’s because computers cannot recognize information the same way you and I can. People follow instructions and process data using letters, numbers, and special characters. For example, if we wanted someone to add the numbers 3 and 5 together and record the answer, we might say “please add 3 and 5”. The system unit, however, is electronic circuitry and cannot directly process such a request.
Our voices create analog, or continuous signals, that vary to represent different tones, pitches and volume. Computers, however, can recognize only digital electronic signals. Before any processing can occur within the system unit, a conversion must occur from what we understand to what the system unit can electronically process.
What is the important fundamental statement you can make about electricity? It is simply this: it can be either on or off. Indeed, there are many forms of technology that can make use of this two- state on/ off, yes /no, present/absent arrangement. For instance a light switch may be on or off, or an electric circuit open or closed. A specific location on a tape or disk may have a positive charge or negative charge. This is the reason, then, that a two state or binary system is used to represent data and instructions.
The decimal system that we are all familiar with has 10 digits (0,1,2,3,4,5,6,7,8,9). The binary system, however, condition consists of only two digits – 0, and 1. Each 0 or 1 is called a bit – short for binary digit. In the system unit, the 0 can be represented by electrically being off and the 1 by electrically being on. In order to represent numbers, letters and special characters, bits, are combined into groups of eight called bytes. Each byte typically represents one character.