Lesson 5: The Fourth Generation of Computers (4G)
Microprocessors
The fourth generation of computers is based on microprocessors. A microprocessor is an electronic component that is used by a computer to do its work. It is also known as a central processing unit or CPU. A microprocessor accepts binary data as input, processes that data, and then provides output based on the instructions stored in the memory. Most of today's computers are 4G.
The first microprocessor was developed in 1971 and was known as Intel 4004. Today’s microprocessors contain billions of transistors on a single chip, which can easily fit in your hand. This development has led to the presence of computers everywhere in our lives today. Since 2004, Intel has introduced microprocessors with multiple cores and millions more transistors, but even these microprocessors follow the same general rules as earlier chips.
1973 - Mobile phones and interconnected computers
A century after the invention of the telephone, Martin Cooper, inventor of the handheld cellular mobile phone, was the first person to ever make a call on a mobile phone in 1973. The mobile phone was a lot bigger than the ones we know today, weighing more than 1kg. It was affectionately known as "the brick", but it quickly became a must-have accessory for wealthy financiers and entrepreneurs.
The concept of a phone being as mobile as the person holding it, with the only restriction being the strength of the signal, revolutionised our idea of communication. In North America, the mobile phone was more commonly known as a cell phone because the local networks were called cells.
Another concept that would eventually revolutionise the world also became real and feasible in 1973 - interconnected computers. The story behind the internet begins much earlier than this. In 1975, the Soviet Union launched Sputnik, the first unmatched satellite in space. In response to this technological breakthrough, the US government set up the Defence Advanced Research Projects Agency (DARPA). Its aim was, and still is, to ensure that the US stays at the cutting edge of technological advances.
In the late 1960s, DARPA decided to connect scientists and engineers in four separate locations by using a network of interconnected computers called the ARPANET. The interconnection of networks became a key goal of industry and the military. ARPA's Transmission Control Protocol/IP, which was first sketched out in 1973 by Vint Cerf and Bob Kahn, would come to dominate the landscape of information transfer. By 1977 ARPA had several networks and they demonstrated that they could connect them all. This became known as the internet.
The Ethernet was also invented in 1973. At the time, there were many interconnecting computers, but the Ethernet became the standard. In the age of wireless communication that we have today, devices do not have any method for direct Ethernet connection.