## History of Computer

A computer keeps a history of its own. Before 3000 or 5000 BC, a Chinese businessman developed a counting machine with a rectangular wooden frame, known as **Abacus**. This device allows users to make computations using a system of sliding beads arranged on a rack. Early businessmen or merchants used the abacus to keep trading transactions.

**John Napier**

Napier is best known for discovering **logarithms**. The Scottish landowner John Napier of Merchiston, known as Marvellous Merchiston, was a mathematician, physicist, and astronomer. In the 16th Century, the Scottish mathematician John Napier developed a method of simplifying the process of multiplication and division using exponents of 10, which were later called logarithms.

Napier published a description of the admirable table of logarithms in 1614. In 1617 he published a method of using a device made up of a series of rods in a frame, marked with the digits 1 through 9 to multiply and divide using the *principles of logarithms.*

## William Oughtred

William Oughtred invented the **slide rule** in 1620. The slide rule was based on the **principle of logarithms**. Oughtred used two such scales sliding by one another to perform direct multiplication and division. One scale slides or slips upon the other. With the proper alignment of the two scales, it is easy to find the product, quotient, or any other function.

## Blaise Pascal

**Pascaline** was developed by Blaise Pascal. In 1642, Blase Pascal began pioneering work on calculating machines and after three years of effort developed 50 prototypes and invented the **mechanical calculator.** It is also known as the Arithmetic Machine because it was the first calculator or adding machine produced in a large quantity and actually used. Pascal designed and built the Pascaline between 1642 and 1644.

## Gottfried Wilhelm Von Leibniz

The first calculator that could perform automatic addition, subtraction as well as multiplication, and division was developed by a German philosopher **Gottfried Wilhelm von Leibniz.**

Leibniz invented the **Stepped Reckoner** and his famous cylinders around 1672 while adding direct multiplication and division to the Pascaline.

## Joseph-Marie Jacquard

In 1801, Josep-marie Jacquard developed a loom in which the pattern being woven was controlled by punched cards.

A punched card can be thought of as a piece of stiff paper that contains digital data represented by the presence or absence of holes arranged at predefined locations.

### Charles Xavier Thomas

Around 1820, Charles Xavier Thomas developed the first successful mass produced mechanical calculator. Thomas Arithmometer that could add, subtract, multiply, and divide.

The Arithmometer or Arithmomètre was the first digital mechanical calculator strong enough and reliable enough to be used daily in an office environment.

It was mainly based on Leibniz ideas and principles.

## Charles Babbage

Babbage is considered to be the “father of the computer”. 1823, He developed kind of machine which calculates the mathematical problmes without human mind. He also found out and develope the concept of storing binary numbers in the machine.

Babbage invented the first mechanical computer, the **Difference Engine**, that eventually led to more complex electronic designs, though all of the essential ideas of modern computers can be found in Babbage’s **Analytical Engine**, which used a principle borrowed from a **Jacquard loom.**

## Lady Augusta Ada Lovelace

The **first lady programmer** who became success to write the program for Babbage’s Analytical Engine. Babbage’s idea of analytical engine could not change into reality until his death in 1871. She was sucessful in discovering some of the key elements of programming and program design.

Additionally, she developed a vision of computers going beyond mere calculating or number-crunching, whereas many others, including Babbage himself, focused only on those functions.

## Dr. Herman Hollerith

An American statistician and inventor who developed a punch card tabulating machine. The first card machine which was electrically activated was used by Dr. Herman Hollerith to compute the statistics of the 1890 United States census. Hollerith designed cards which were the size of dollar bill. It had 288 locations for punching holes.

The Computing-Tabulating-Recording Company was formed in 1911 through the merger of Hollerith’s company and several other companies.

The company became one of the largest and most successful companies of the 20th century in 1924 when it was renamed **“International Business Machines” (IBM).**

## Boolean Algebra

George Boolean, a British mathematician, introduced mathematics of logic known as boolean algebra. Boolean algebra is the branch of algebra where the variables represent true and false values, denoted by 1 and 0, respectively.

The main foundation of digital computers is boolean algebra it consists of only two numbers and during the designing and analyzing of the system we only consider 0 and 1.