Calculator and Computer
There is only one part of calculator.
Screen of calculator is very small.
It works very slow and do simple calculation.
It cannot do lots of work.
There is only numeric key in calculator.
Computer has basically four main parts as Keyboard,CPU,Mouse,Monitor.
It has a big screen.
It can do simple and complex sums.
It can do lots of job as you can paint,read,draw with a very fast speed.
The keyboard has number key,alphabet key and special key.
Computer in early stage
In olden days,we calculated using our fingers.Even today,we can use the same formula.Different methods were invented to do the calculation accurately and fast.The story of computer had started long ago.Since then it had undergone many stages.
Some early computers
Abacus was the earliest calculating device,invented in China.It was invented mainly for counting.
Napier’s Bones,a calculating device for multiplication,division,addition and subtraction was invented by John Napier.
Pascaline,a calculating device was invented by Blaise Pascal.Pascal is a numerical wheel calculator.
Difference Engine:Charles Babbage is the father of computer.He designed Difference Engine to calculate mathematical table.He then designed Analytical Engine which had many similarities to modern computer.
Computer Generation and their Type
Classification of computer according to the technology used:
First Generation of Computers
The first electronic calculator MARK-I started the first generation.This machine was very slow but it could perform basic arithmetic as well as more complex equations.
Characteristics of first generation computers:
Used vacuum tubes.
Had huge size.
Large number of air conditioners were used.
A single program was loaded.
Very delicate and not reliable.
Used magnetic drums for storage.
Second Generation of computers
The major development that had started the second generation of computers was the invention of transistor.Vacuum tubes were replaced by transistors in the computers of second generation.
Some characteristics of second generation computers were:
Used transistors instead of vacuum tubes.
Smaller in size and used less power.
Had less heat production rate.
Comparatively faster and reliable.
Cheaper than first generation computers.
Capable to handle a large amount of data.
Third Generation of Computers
Integrated Circuits were introduced in third generation.
A single IC replaced a number of transistors because all the functions were performed by a single IC.
Some distinguishing features of computers of this generation were:
Used Integrated Circuits(IC)
Decreased in size and weight.
Cheaper than earlier computers.
Could easily be replaced and maintained.
Fourth Generation of computers
The computers of this generation have been improved by reducing the size of IC.
Some characteristics of Fourth Generation computers were:
Used microchip with a technique known as Very Large Scale Integration(VLSI).
Reduced considerably in size.
Low in cost,affordable to common man.
Increased memory capacity.
Worked with great speed.
Developed network of computers.
Fifth Generation of Computers
Fifth generation of computers are based on artificial intelligence.With the use of artificial intelligence,computers can hold conversation with its human operators and can also learn from its own experience.
Types of Computers
Micro computers have brought revolution in computers because of their size and cost.All PCs come under the micro computers.
Common characteristics of micro computers are:
Cheap and easy to use.
Have limited input and output capacities.
Limited range of softwares can be used.
Have self contained units which can be moved easily.
Designed to be used by one person at a time.
Have CPU and a keyboard for input.
Hard disk and floppy disk drives are used to enter and store data and programs.
Monitor and printer are used to get the output.
Mini computers are less efficient and store less data than mainframe computers.
Have limited range of peripherals.
Limited softwares are used.
Can be directly operated by the user.
Computer:An intelligent Machine
A machine is a manmade device which makes our work easier.Machines help us to work faster and correctly.
Refrigerator makes things cool.
Washing machine washes clothes.
Mobile phone helps to communicate with friends,parents.
TV shows you cartoons,movies,news and other programs.
Motorcycle helps you going to different places and enjoy riding.
AC helps keep room cool.
Calculator helps doing arithmetic operations like addition,subtraction,multiplication,division.
Likewise computer is also a machine that stores information and does calculation.
A computer is a smart machine because it works faster than us,it has memory like us and can store information.
It never commits mistakes.
It never gets tired.
It helps us playing games,surfing Internet,sending email.
Computers and Us
Computers are helpful to us in many ways.A computer is sometimes better than us.
A computer has memory like us.
It works faster than us.
It never commits mistakes.
It never forgets.
It never gets tired.
It does not need food to get energy.
It never complains.
But in some ways,we human beings are better than computers.
We think on our own.
We do not work on electricity.
We have a brain.
We do not need orders to work.
WHAT IS COMPUTER?
A computer consists of many different parts. All these parts help us to do some work.
Some help us feed information into the computer others help us display the information and still other store the information for later use. We can, therefore, group the parts into input, output and storage device.
What is computer? Computer is a machine which runs on electricity and carries out our instructions.
Let us take example to understand the concept of input/output devices. When you have exams, you work hard. If you work hard, you get good marks. So, your working hard becomes an input. When you work hard, the output or result brings good marks.
PARTS OF COMPUTER
There are three main parts of computer:
Central Processing Unit
Keyboard 100ks like a typewriter. It is made up of different types of Keys. These keys are small boxes on which some alphabets, numbers or signs are printed.
Alphabetical Keys: A, B, C,D,…….. to Z are English alphabets and the keys on which these alphabets are printed are called Alphabetical Keys. There are 26 alphabetical keys on the keyboards.
Numerical Keys: 0, 1, 2,…..to 9 are numbers and the keys on which these numbers are written are called Numerical Keys.
Special Keys : ?,!, #,%, & etc are called signs. These signs are present on the Numeric Keys.
CAPS LOCK KEY: This key is used when the entire sentence or word or a letter is to be typed in capitals.
Space Bar Key:The longest key on the keyboard is ‘Space Bar Key’.Nothing is written on Space Bar key.
Enter Key:Enter key must be pressed after typing every command.
Shift Key:Shift key is present on both sides of the keyboard.Though both the keys do the same thing,they are provided for ease of working.
Delete Key:is used to remove errors from lines.
CENTRAL PROCESSING UNIT(CPU)
CPU is the brain of computer.As all thinking and calculation are done by brain,in the same manner all calculations are done inside the CPU.
MONITOR:Monitor is a display unit,it is also called as Visual Display Unit(VDU).It looks like a TV.
Whatever we type from keyboard is displayed on monitor.
USES OF COMPUTER
MAN AND COMPUTER
COMPUTERMANComputer is always right.Man would be sometime wrong.Computer does not get tired.Man gets tired.Computer is fast.Man is slower than computer.Computer has no feeling.Man has feeling.Computer has no brain.It works on instruction.Man has brain.Computer can do only a few work.Man can do all kinds of work.
Computer help everywhere-
Computer helps the doctor.With its help,the doctor can cure the disease very quickly.
Computer helps for booking ticket at railway station and airport.
Computers are also used in offices,banks for calculation and for maintaining records.
Do you ever go to market?A computer helps in market.
We can write letters at the computer.
Computer helps in studies at school.
Uses of Computer
Computers are used at many places for performing many jobs.
One can write letters and send messages to one’s friends and relatives through a computer.
One can also learn many new things with the help of the Internet on the computer.
A computer helps us in drawing pictures and painting on the computer.
One can listen to music and also watch movies on the computer.
We can play different games on the computer,like solitaire,minesweeper,Lionking.
It is also used for mathematical operations like addition,subtraction,multiplication and division.