History of Computers

The golden age of computers began with the digital revolution, but people have been using computers in their daily lives since the beginning of civilization. The history of computers began with simple adding devices. Milestones in the 20th century included the invention of the transistor and the development of the microprocessor, which led to the modern-day computer.

**The Abacus and Adding Machines**

The first computers did not have electrical circuits, monitors or memory. The abacus, an ancient Chinese adding machine, is one of the original computing machines, used as early as 400 B.C. It can't do many of the computations that a modern electronic calculator can do, but it in the right hands it can make calculating large sums as easy as moving beads around. Famous mathematicians such as Leonardo da Vinci and Blaise Pascal invented more sophisticated calculators using gears and punch cards.

**The Vacuum Tube**

The invention of the vacuum tube in 1904 kicked off a revolution in computers. A vacuum tube is a tube that has had all air and gas removed, making it perfect for controlling electrical circuits. By using vacuum tubes together with hundreds or thousands of electrical circuits, a computer's vacuum tube can perform calculations by turning these circuits on (current flowing) or off (no current flowing). Computers from before 1950 often had vacuum tubes in their processors.

**The War Years (1939-1945)**

Many developments in modern computing took place during the war. Code breaking machines were built, including the Colossus. A man called Alan Turing (sometimes called the forefather of modern computing) worked on this machine.

**The Transistor and the Microprocessor**

Developed by Bell Laboratories in 1947, transistors are made of a metal (usually silicon) that, like vacuum tubes, can switch circuits on and off. Current technology makes it possible to make transistors as small as a single molecule. This allows computer manufacturers to make microprocessors (the "brains" of the computer) small enough to fit in the palm of your hand but still capable of performing billions of calculations in a single second.

**The Invention of the Microchip (1960s)**

The microchip is the brains of the computer. Microchips are very small and can carry out millions of instructions every second. Their small size meant that computers were much smaller in size. They were developed in the late 1950s. The first microchips became available in the early 1960s.

**The Early days of the Internet**

The Internet is the terms for the physical connection of computers, and networks. It can be traced back to the early 1960s in America. The system was originally called ARPANET and was not for public use. The Internet gained in popularity in the 1980s with the invention of the World Wide Web.

**The First PCs (1980s)**

The first personal computer can be traced back to the 1970s. The development of the microchip meant that PCs could be made quite small. Although developed in the 70s they did not really become mainstream until the 1980s. Computers at this time were being made by companies like Xerox, IBM and Amstrad.

**Computer Networks**

The most recent milestone in the history of computers has been the birth of the Internet and other networks. In 1973, Bob Kahn and Vint Cerf developed the basic idea of the Internet, a form of communication between different computers through packets of data. Tim Berners-Lee developed the World Wide Web, a network of Web servers, in 1991. A year later, the number of Internet "hosts" (computers connected to the Internet) exceeded one million.

**Computing today (2000 onwards)**

Computers are becoming smaller and more integrated. There are more hand-held computer devices such as PDAs, mobile phones and music players. The Internet has become more widespread and quicker to use. People like to get access to information when they want it. Computers are becoming cheaper to buy.

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by **SULEMAN NAZIR CHAUDHARY**