Data and instructions cannot be entered and processed directly into computers using human language. Any type of data be it numbers, letters, special symbols, sound or pictures must first be converted into machine-readable form i.e. binary form. Due to this reason, it is important to understand how a computer together with its peripheral devices handles data in its electronic circuits, on magnetic media and in optical devices.
Bits, bytes, nibble and word
The terms bits, bytes, nibble, and word are used widely in reference to computer memory and data size.
Bits: is the basic unit of data or information in digital computers, expressed in binary forms 0 or 1.
Byte: a group of bits (8 bits) used to represent a character. A byte is considered as the basic unit of measuring memory size in computer.
A nibble: is half a byte, which is usually a grouping of 4 bytes.
Word: two or more bits make a word. The term ‘word length’ is used as the measure of the number of bits in each word. For example, a word can have a length of 16 bits, 32 bits, 64 bits, etc.
Computers not only process numbers, letters and special symbols but also complex types of data such as sound and pictures. However, these complex types of data take a lot of memory and processor time when coded in a binary form. This limitation necessitates the need to develop better ways of handling long streams of binary digits. Higher number systems are used in computing to reduce these streams of binary digits into manageable form. This helps to improve the processing speed and optimize memory usage.
Number systems and their representation-
A number system is a set of symbols used to represent values derived from a common base or radix. As far as computers are concerned, number systems can be classified into two major categories:
· Decimal number system
· Binary number system
· Octal number system
· Hexadecimal number system