COMPUTER

Commonly Operating Machine Particularly Used for Trade, Education & Research(COMPUTER)
The Computer

What’s a computer?A computer is an electronic device that accepts data and instructions, processes the data according the instructions and gives the desired output on a prescribed output device.
How computer works

Input stage –This stage comprises of entering some sort of data into a processing. E.g. typing data through keyboard.

Processing Stage –This stage comprises of performing certain tasks on the data to produce the required output. E.g. It process (works on) the data.
Output stage –This stage comprises of obtaining the results on a prescribed output device. E.g. the data is displayed on the monitor.
Advantages of computers
Very fast, accurate and reliable.
Never does careless mistakes and never gets tired.
Efficiency not decreases with age.
Useful in all the fields.
It has a mass storage capacity, if we use the secondary storage device.
Application of computers
Computers are used in:
Scientific research
Business administration
Industrial application
Meteorology
Space technology
Education
Hospitals
Court, etc…
Organization of a computer system

Input devices: Keyboard, Mouse, etc.

Output devices: Monitor, printer, speaker, etc

Central Processing Unit [C.P.U.] :Central processing unit controls all the activities of the computer system. It is here that the actual processing takes place.
The components of C.P.U. are :
Control Unit: -Control unit is the most important unit within the C.P.U. It controls the overall activities of the computer.

Primary Storage Unit (Main memory): -The Primary Storage unit is also called as internal storage or main memory. Its function is to store data, instructions and intermediate final results temporarily. RAM and ROM make up primary storage.
Random Access Memory (RAM): RAM stands for Random Access memory. As the name suggests data or instructions could be accessed quickly /randomly from the RAM. It is a temporary/volatile memory i.e. whatever data or instructions are in RAM would be lost when the computer is switched off

Read only Memory (ROM): ROM stands for Read only Memory. As the name suggests, data can only be read from this memory. It is a permanent /Non-volatile memory i.e. the contents of ROM would not be lost when the computer is switched off. The contents of ROM could only be read, they could not be modified or erased. Within the ROM the manufacturer stores a program needed by the computer.

Representation of Data within the Computer System.

• A computer cannot directly understand human languages like English, Tamil, Hindi etc.
• It only understands a coded language. SO everything fed into the computer gets converted into coded language. Only then does it start processing
• All the data is represented within the computer system as 0’s and 1’s. BITS.

Bits & Bytes
0 and 1 are called BITS (Binary digits).
8 BITS = 1BYTEA combination of any 8 bits is called a BYTE

Each Character (alphabet, number or Symbol) of the English Language is represented by 8 Bits(Byte) within the computer.

Units of Measurement of Storage

Byte :-8 Bits make 1 Byte.

Kilobyte :-1024 Bytes make 1 Kilobyte

Megabyte : -1024 KiloBytesmake 1 Megabyte

Gigabyte :-1024 Megabytes make 1 Gigabyte

Terrabyte:-1024 Gigabyte make 1 Terrabyte.