WORD

• The main memory contains a large number of semiconductor storage cells each capable of storing one bit of information.
• These cells are processed in groups of fixed size called words.
• The main memory is organized so that the contents of one word containing n bits can be stored or retrieved in one basic operation.
• To provide easy access to any word in memory, a distinct address is associated with each word location.
• A given word is accessed by specifying its address and issuing a control command that starts the storage or retrieval process.
• The time required to access one word is called memory access time.
• The number of bits in each word is often referred to as the word length of the computer.
• Large computers have usually 32 or more bits in a word and micro computer word lengths range from 8 to 32 bits.
• The capacity of the main memory is few hundred thousand words, whereas medium and large machines normally have millions of words.
• Data are manipulated within a machine in units of words, multiples of words or parts of words.
• A typical access to the main memory results in one word of data being read from the memory or written into it.