DEFINITION OF INPUT UNIT
Data and instruction must enter the computer system before any computation can be performed on the supplied data. This task is performed by the input unit of the computer that links the external environment with computer system. Data and instruction enter input unit in forms that depend on the particular device used. For example, data is entered from a keyboard in a manner similar to typing, and this differ from the way in which data is entered through a card reader which is other type of input device. However regardless of the form in which they receives their inputs, all input devices must provide a computer system with data that are transformed into the binary codes that the primary memory of the computer is designed to accept. The transformation is accomplished by units called input interfaces. Input interfaces are designed to match the unique physical or electrical characteristic of input device to the requirement of the computer system.
FUNCTIONS PROVIDED BY INPUT UNIT
- It reads the list of instruction and data from the outside world.
- It converts these instructions and data in the computer acceptable form.
- It supplies the converted instructions and data to the computer system for further processing.