What is **Computer**?

**Computer** is an electronic device that takes the some input **data** and instruction to give out the output as a result at very high speed and accuracy.

*A **computer** system is made by the combination of hardware and **software** .

**Early History Of Computers**

**Abacus-:**

It was prepared by Mesopotamians around 1000 years before the birth of Jesus Christ .It was mainly used for counting.

**Napier’s Bones -:**

It was prepared by a Scottish mathematician who’s name was Napier’s Bones.He devised set of rods, called Bones to transform the process of complex multiplication and division in to much simpler tasks of addition and subtraction.

**Slide Rule**-:

It was prepared by John Napier .It was used for performing complex and complicated calculations such as statistical and **Engineering** calculation at very fast speed.

**Pascal’s Calculator**-:

It was prepared by a French** mathematician**, physicist and theologian Blaise Pascal. It was used to perform arithmetic operation like additions and subtractions.

**Leibniz’s Calculator**-:

It was prepared by Gottfried Leibniz by improving Pascal’s **Calculator**. This **machine** was able to do arithmetic operation like addition ,subtraction,multiplication and division.

**Jacquard’s Loom**-:

It was invented by a French weaver Joseph Jaquard by using Punch cards to produce patterns on cloth. The **machine **entire operation was done by a program’s control.It influenced too much for the later inventions and advancement of **Computing** devices.

**Babbage’s Difference Engine**-:

This **machine** was developed by a mathematics professor Charles Babbage. This machine was able to calculate logarithms up to high precision degree, different functional values and polynomials by finite difference technique.

**Babbage Analytical Engine**-:

This was also developed by Charles Babbage .This analytical Engine was able to perform all four arithmetic operation along with to compare quantities and then decide which of the instructions sequence to follow. Due to Difference Engine and Analytical Engine inventions Charles Babbage is known as the Father Of **Computer.**

**Hollerith’s Machine**-:

It was invented by Herman Hollerith to fulfill the dream of Charles Babbage .He fabricated the first **electromechanical punched card** tabulator that used punch cards for input, output and instructions.

**Mark-1-:**

It was a **Electromechanical Computer** constructed by Prof Howard Aiken of USA in year 1943.It had capability to **multiply two 10-digit numbers in 5 seconds**, which was a record at that time .This was the first **machine **,which could perform according to pre Programmed instructions automatically without any manual interference and also the first operational general purpose **Computer**.

**ENIAC**-:

This machine was designed by the scientists of Pennsylvania University of USA in 1946.This **Computer **was 20 feet long and 40 feet high and consumed as much electric power as was sufficient to light a small city. But this machine was faster than earlier machine. ENIAC stand for Electronic Numerical Integrator and **Computer**. The Biggest problem of this** Computer** was that all the instruction were hardwired within the **Computer**.

**EDVAC**-:

This **computer** was designed and constructed in 1950 in Moore school Of America.It was capable of taking both data and instruction by making use of **Punched Cards**.Thus problem of hardwired instructions which was there in ENIAC was solved in this computer and its performance was much better than earlier **computer**.

**Modern Computer**-:

It was developed by** IBM** in 1981.it was small in size ,very powerful and functioning was very simple. This computer was called Personal **Computer** or PC which became popular very soon. After1981 a lot of improvements were made in PC due to these improvements PC become very powerful and easy to operate . Now PC’s function become so simple that even a child can operate it.