Abacus

The earliest calculating device was known

as Abacus. Its exact origin is unknown. It is

invented 2000 years ago. Its has 2 section:

Heaven and Earth

which are separated by beam. The heaven is

also called the upper deck, and the earth is also

called the lower deck. The Abacus was used to

perform addition and subtraction. It is still used

today in china and some other countries.

History Of Computer

• Abacus
• Napier's Bone
• Slide Rule
• Pascaline
• Leibniz's Calculating Machine
• Charles Babbage
• Mark 1
• Attansoff Berry Computer (ABC)
• Electronic Numerical Integrator and Calculator (ENIAC)
• Electronic Discrete Variable Automatic Computer (EDVAC)
• Universal Automatic Computer (UNIVAC)

Benefits and Limitation of Computers

The fact that the computers have made their impact on almost all aspects of our life in today's world can hardly be questioned. The question that you may ask here is how do you benefit from using a computer.

A Computer provides three Basic benefits:

• Speed
• Accuracy(accurate work)
• Diligence(careful hard work)

Computers work at very high speeds and are much faster than human being. The human equivalent of an average computer would be one million mathematicians working 24 hours a day. A computer rarely makes mistakes. In fact, most computer errors are cusec by human facilities. Unlike human, computers simply do not get bother or tired. The monotony of repetitive works does not affect computer. Unanticipated situation arises, computer will either produce erroneous results or abandon the task altogether. They do not have the potential to work out and alternative solution.

The Part of Computer system

Parts of computer system are :

• Hardware
• Software
• Data
• Users

Hardware

A computer's hardware consists of electronic devices; the parts you can see and touch. The term "device" refers to any pieces of hardware used by the computer, such as a keyboard, monitor,modem,mouse etc.

Software

Software consist of organized sets of instructions for controlling the computer. Some programs exist for the computer's use, to help it manage its own tasks and devices. Other programs exists for the user, and enable the computer to perform tasks for you, such as creating documents. A computer solves a wide variety of programs, but it solve the programs on it own. Its must be provide with instructions is the form of a computer program. A program is list of instructions written in a special language that computer understands. It tells the computer which operations to be perform and in what sequence to perform them.

Data

Data consists of row facts, which the computer can manipulate and process into information that is useful to people. Computerized data is digital, meaning it has been reduced to digits, or numbers. The computer stores and reads all data as number. Although computers use data in digital form, they convert data into form that people can understand, such as text, numerals, sounds and images.

Users

People are the computer's operators, or users. Some types of computers can operate without much intervention from people, but personal computers are designed specifically for used by people.

Central process Unit(CPU)

This is main part of computer which help to operate system program in computer. There are four steps that nearly all CPUs use in their operation: fetch, decode, execute, and writeback

Monitor

It is an electronic device which help us to visual display.The size of screen will be rectangular.

liquid crystal display(LCD) and Cathode ray rube(CRT) are types of Monitor and Plasma

• Cathode Ray Tube

I t hav high dynamic range and excellent colours as well as wide gamut and low black level.It can display natively. its will be large size and high power consuption.thats why its usually cheaper then LCD.

• Liquid Crystal Display

Its very compact and light and limited viewing angle.it no light and flicker depending on back light techjnology.

• Plasma

It hav high compact and light with high contrast ratios as well as excellet colour. It will be more expensive then CRT.

Parts of Computer

Here are some parts of computer.

1. Monitor
2. CPU
3. Keyboard
4. Mouse
5. Floppy drive
6. DVD/CD drive
7. Webcam
8. Head set
9. printer
10. scanner
11. Microphone