Components of Digital Computers

A digital computer can be broadly classified as a collection of four components. They are:


1. Input Unit-
The input Unit provides an interface between the users and the machine, for inputting data and instruction etc. one of the most common examples is the keyboard. Data can be input in many more forms – audio, visual, graphical etc.
Some input device are:


1. Keyboard
2. Mouse
3. Voice data entry
4. Joy stick
5. Light pen
6. Scanner
2. Output Unit


Like the input Unit, the Output Unit also provides an interface between the user and the machine. A common example is the visual display unit of a personal computer. The output unit receives the data from the CPU in the form of binary bits. This is then converted into a desired form (graphical, audio, visual etc) understandable by the user.

Some common output devices are:
1. VDU(Visual Display Unit).
2. Printers Speakers
3. Secondary Storage Devices.
4. The Central Processing Unit

The central processing unit is the brain of the computers system. The input and output devices may vary for defferent application, but there is only one CPU for a particular Computer. The specifications of computer are basically characterized by its Central Processing Unit.

1. The Arithmetic Logic Unit.
2. The Control Unit
3. Main Memory


5. The Main Memory Unit
The main memory also known as the primary memory is a part of the central processing unit and is a combination of both RAM and ROM. We shall discus the RAM and ROM later .

RAM- Random Access Memory is a read write memory i.e. information can be read as well as written into this type of memory. It is volatile in nature, i.e., the information it contains is lost as soon as the system is shut down unless ‘saved’ for further usage by users. It is basically used to store programs and data during the computer’s operation.

ROM- Read Only Memory as the name may suggest contains information that can only be read, i.e., you cam’t write on this type of memory. It is non-volatile or permanent in nature. It is basically used to store permanent programs such as program for the functioning of the monitor.