History of Computers

When the human race started doing some trade, it felt a need for a calculating device. The first calculating device, which was used 2000 years ago was called abacus and the improvements in the calculating device in that age were slow. The next change came after about 1600 years. Following this, the changes were frequent and the mechanical  desk calculator was developed around 1800 A.D.  in 1833, Prof. Charles Babbage, the father of the computer, developed a machine called analytical engine, which was the base for the modern digital computer.

Uses of a computer:

• Computer  can be used to draw pictures.
• Computer can be used to solve sums.
• Games can be played with computers.
• Computers can be used to play music and to listen songs.
• Computers can be used to store large amount of data.
• Computers can be used to create the cartoon movies.
• Computers can be used to watch the movies.
• Computers can be used for online reservations like railway tickets reservation and flight tickets reservations etc.,
• Computers are used in schools to teach lessons to the students.
• Computers are used in banks to keep records on accounts, withdrawals and deposits of the customer.
• The computer can be applied to more creative areas like forecasting, research and simulation.

Process:

• Computer receives data from the input device (keyboard. Scanner etc.,)
• Computer stores that data in memory.
• Computer processes the data and stores the result in memory.
• Computer sends that result to an output device (monitor) or to a printer.

Parts of computers:

Input unit:   

The key board is the main input key device, through which the data is put into computer for the computation.  Other examples for the input devices are mouse and joystick.

CPU:    

It  stands for Central Processing Unit. It is the brain of a computer.  It is also known as system unit. The system unit consists:

Memory unit:

When we feed the data into the computer, the CPU first sends it to the memory     unit, where it is stored.  

Control unit:

It deals with the input as per the instructions using the memory and the ALU. After the processing, it sends results back to the memory from where they will send the output device.

ALU: (Arithmetic and Logic Unit)

It decodes program instructions, solves arithmetic problems and carries out tasks which need logic to arrive at an answer.

Output unit:

The information that comes out of the computer is called the output. Monitor and Printer are output devices. Generally output is viewed on screen and printout is taken From printer.