History of computer

Necessity is the mother iof the invention.The saying holds true for computers too.Computers were invented because of man’s search for last and accurate calculating devices.Computer  was not invented by a person in a particular time.It is the result of the gradual development of calculating technology, in this we discuss the development of different and machines which led to the development of modern computers.

Abacus

Approximately 4,000 years ago, the Chinese invented the Abacus. It was the first machine used for counting and calculating. It is made of a wooden frame, metal rods, and wooden beads. It takes a great deal of time and practice to learn how to master the use of an abacus. An abacus is a person who is very experienced in using an abacus. Today, the abacus is still used widely in China and other Asian countries to count and calculate, just as we use calculators.

Each bead has a specific value. Reading from right to left, the beads in the first column are worth 1, in the second column the beads are worth 10, in the third column the beads are worth 100, etc. Addition, subtraction, multiplication, and division are performed by moving the appropriate beads to the middle of the abacus.

John Napier & Napier's Bones

In the early 17th century, John Napier, a Scottish mathematician, invented another calculating tool. It used marked strips of wood or bone, side by side, to multiply and divide. This tool became known as "Napier's Bones."

The Pascaline

The Pascaline was a wooden box that could only add and subtract by means of a series of gears and wheels. When each wheel rotated one revolution, it would then turn the neighboring wheel. On top of the wheels were a series of windows through which the totals could be read. About 50 models were constructed and were made of wood, ivory, ebony, and copper.

1673-Wilhelm Gottfried Liebniz and The Stepped Reckoner

In 1673, German inventor Gottfried Liebniz perfected the Liebniz Calculator. Liebniz entered a university at fifteen years of age and received his bachelor's degree at seventeen. This machine is sometimes called The Stepped Reckoner. The Liebniz was also a calculating machine, but much superior to that of the Pascaline. It could do more than just add and subtract. The Liebniz Calculator could also multiply, divide, and find square roots of numbers. It too was mechanical and worked by hand. A crank was added to speed up the work of this calculator. It was used by mathematicians and bookkeepers.

 

Liebniz's Calculator

Mr. Liebniz believed that it did not make sense fo men to spend hours and hours doing mathematical calculations when he could invent a machine that would work much faster. Would you rather add a long list of numbers with a pencil and paper or use a calculator?

1801-Joseph-Marie Jacquard & the Jacquard's Loom

Jacquard's Loom

In 1801, Jacquard invented the Jacquard loom. It was a weaving machine that was controlled by punched cards. While the loom was being pumped, cards with holes in them were attached together in a pattern through which strings of thread were automatically fed. These cards would feed the right pieces of thread into the loom to make a beautiful cloth.

His invention scared other weavers because it made cloth faster and better than they could by hand. As a result, Jacquard's house and loom were burned down.

This violent act did not discourage Jacquard, for he built another loom. Weavers today still use the Jacquard Loom.

In the years to follow, variations on jacquard's punched cards would find a variety of uses, including representing the music to be played by automated pianos and the storing of programs for computers.

Charles Babbage & his Engines

In the early 1820s, an English mathematician by the name charles Babbage, designed a computing machine called the Difference Engine. This machine was to be used in the calculating and printing of simple math tables. In the 1830s, he designed a second computing machine called the Analytical Engine. This machine was to be used in calculating complicated problems by following a set of instructions.

Analytical Engine

The Analytical Engine was a mechanical computer that can solve any mathematical problem. It uses punch-cards similar to those used by the Jacquard loom and can perform simple conditional operations.

 

Difference Engine

However, neither of these machines were ever finished because the technology at the time was not advanced enough, and both of his projects lacked financial funding. The computing machines made in the 1900s, and even those today are based on the designs of the Difference Engine and the Analytical Engine. This is why charles Babbage is known as the "Father of Computers."

Augusta Ada Byron, Countess of Lovelace

Much of what we know about Babbage and his machine comes from the papers of Augusta Ada Byron, countess of Lovelace and daughter of the poet Lord Byron. lady Lovelace was a genius in math. curious about Babbage's work, she translated an article about the analytical engine from French to English. she added some important notes of her own about how the machine should work. She outlines the fundamentals of computer programming, including data analysis, looping and memory addressing.

Lady Lovelace also helped Babbage with programs for the Analytical Engine. Many of her ideas are like those used in today's computer programs. Sadly, like Babbage, lady Lovelace never lived to see her ideas used. She died at age 36 while Babbage was still working on the Analytical Engine. Her work has long outlived her, however. She is now called "the first programmer," and a programming language used chiefly by the U.S. government was named Ada in her honor.

Electro-mechanical Machines

1890-Herman Hollerith & his Tabulating Machine

 An American inventor by the name of Herman Hollerith wanted to speed up the work involved in taking the government census. In 1890, 50 years after charles Babbage's death, Hollerith invented a machine called the tabulating Machine, using notes that were left by Babbage.

Prior to this invention it took nearly eight years to count everyone in the United States and add up all the information about where people lived, their ages, and what their jobs were. The Tabulating Machine used punched cards to record and sort data or information. Each hole punched meant something. If a hole had been punched, a pin would pass through it to make an electrical contact with mercury in a cup below. This turned motors that moved numbers that counted. Approximately 65 cards could be passed through this computer in a minute, and in 1890 it took only 2.5 years to complete the U.S. Census.

Hollerith did not stop with this one invention. He began a company by the name of the Tabulating Machine Company. Eventually this company changed its name to International Business Machines (IBM)--one of the largest computer companies in the world.

 

1930-Vannevar Bush and the Differential Analyzer

In 1930, Vannevar Bush introduced the first electronic "computer" in the United States. It was an analog device. That is, it could measure quantities that changed continuously, such as temperature and air pressure. It used vacuum tubes to switch electrical signals that performed calculations. Bush's machine could do 25 calculations in a few minutes. To show the results, a pen fixed above a drawing board was used to draw a curve on a graph.

The Differential Analyzer weighed 100 tons, used 2000 vacuum tubes, thousands of relays, 150 motors, and approximately 200 miles of wire.

Double-click to see simulation

 

1944-Howard Aiken and the Mark I

The next major invention in the history of computing began in 1937. In that year Howard Aiken outlined a plan for a machine that could perform math problems involving very large numbers. Because it handled distinct amounts or numbers, it was a digital (rather than analog) device.

In 1944, IBM paid engineers to build Aiken's machine. Called the Mark I, it was made up of 78 adding machines and desk calculators that were connected by almost 500 miles of wires. In one second, the Mark I could add three eight-digit numbers; for example, 12,345,678 plus 90,123,456 plus 78,901,234. It could print out its results on punched cards or on an electric typewriter.

The machine had some serious disadvantages, however; it was enormous--51 feet long and 8 feet high. Its 3,000 electrical switches made a terrible racket as they kicked on and off. The Mark I was expensive and complicated to build. After all, it had one million parts and weighed approximately 5 tons!

Grace Hopper

One of the primary programmers for the Mark I was a woman, Grace Hopper. Hopper found the first computer "bug": a dead moth that had gotten into the Mark II and whose wings were blocking the reading of the holes in the paper tape. The word "bug" had been used to describe a defect since at least 1889 but Hopper is credited with coining the word "debugging" to describe the work to eliminate program faults.