Alphanumeric Codes & Binary Storage and Registers

Alphanumeric Codes

Digital computers' applications require handling of the data that requires not only of numbers but also of letters. For example, an insurance company with millions of policy holders may use a digital computer to process its files.

To processes holder's name in the binary form, it requires having a binary code for the alphabet. In addition, the same binary code must represent decimal number and some other special characters.

An alphanumeric code is a binary code of a group of elements consisting of the ten digits. The 26 letters of the alphabet. And a certain number of special symbols such as $.

The total number of elements in an alphanumeric group is greater than 36. Therefore, it must be coded with a minimum of six bits 26 = 64 but  25 = 32 is insufficient.

Binary Storage and Registers

binary storage and registers
The discrete elements of information in a digital computer must have a physical existence in some information storage medium. Furthermore, when discrete elements of information are represented in binary form, the information storage medium most contain binary storage elements for storing individuals bits.

A binary cell is a device that possesses two stable states and is capable of storing one bit of information.

The input to the cell receives excitation signals that set it to one of the two states. The output of the cell is a physical quantity that distinguishes between the two states. The information stored in a cell is a 1 when it is in one stable state and a 0 when in the other stable state.

Example of the binary cell are electronic flip-flop circuits, ferrite cores used in memories, and positions punched with a hole or not punched in a card.