One of the most widely used coding systems to represent data in main computer memory is the American Standard Code for Information Interchange, called the ASCII Code. In ASCII system, each digit in a numeric value is stored in a single byte. For example, the numeric value 4263 would require four bytes of memory when stored using the ASCII code. The ASCII code uses the right most seven bits of the 8-bits = one byte to represent number, letters of the alphabet, and special characters. This provides for the representation of a maximum of 128 individual characters. With the ASCII code, the left most bit is not used to represent characters. Each letter of the alphabet is represented by a unique combination of bits being ‘on’ or off. Table 2.5 above illustrates the representation of the letters of the alphabet A-Z.