Unit 4

I. Read the title and subtitles of the text and predict what the text is about. Scan the text and say if you were a success in guessing the content of it.

Text A

Historical perspective

As people learn new things, they use that knowledge to generate more new information. The more information they have, the more they try to find better ways to store it, process it, and retrieve it. During the past forty years, a giant leap has been made in dealing with information. Men and women have developed high-speed computers which accept, store, process, and give out information. The computers work faster than people like Pascal or Hollerith ever dreamed possible.

The age of "modern computers" began in 1944. That year an American engineer at Harvard University, Howard Aiken, built a computer. It worked very much like a machine designed more than 100 years earlier – Babbage's Analytical Engine. Aiken's computer, called the Mark I, accepted information through punched cards. It stored and processed the information. It printed the results on an electric typewriter. The Mark I was able to do many different tasks. It was a huge machine. It took up the space of a school gymnasium. It took only a few seconds to calculate a math problem – quite a feat for 1944! The Mark I is known today as the world's first electro-mechanical computer.

Soon after the invention of the Mark I, scientists began to build computers that had almost no moving parts. That is, they were electronic rather than mechanical. Most of the computers that you'll be reading about are called digital computers. A digital computer changes information into digits to be stored and processed. Electronic digital computers quickly replaced the Mark I. In fact, a

30

few years after the Mark I was built, electromechanical computers became oldfashioned, and weren't used any more.

There have been several major changes in digital computers during the past forty years. Each change ushered in a new "generation" of computers. Just as we have different generations of people in a family, computers have generations, too.

First-Generation Computers

As moving parts inside computers were replaced by electrical circuits, computers worked faster and more efficiently. The first all-digital computer was completed in 1946 at the University of Pennsylvania under the direction of two engineers, John W. Mauchly and J. Presper Eckert. The computer, called the ENIAC, was even bigger than the Mark I. It weighed over 30 tons! It conducted electricity through vacuum tubes. In fact, the computer used over 18,000 vacuum tubes! Vacuum tubes get hot, and 18,000 of them created a lot of heat. So, it was necessary for the ENIAC to have special air conditioning units to keep it cooled down.

The ENIAC was considered quite a "brain." It was 300 times faster than the Mark I. It worked a thousand times faster than a person using a desk calculator. It was given a problem that would have taken 100 engineers, working eight hours a day, an entire year to solve. The ENIAC solved the problem in two hours.

Soon after the ENIAC was built, John von Neumann had the idea of storing a computer program in the computer's memory. Up until this time, only the numbers used in the program were stored in the memory. Von Neumann's idea enabled people to build computers that worked faster than the ENIAC. In fact, today's computers are based on von Neumann's idea of storing programs in the memory.

31

A few years later, in 1951, Eckert and Mauchly designed another computer called the UNIVAC. The UNIVAC was even larger than the ENIAC. Eckert and Mauchly sold the UNIVAC to the United States Census Bureau. Other models of the UNIVAC were built and sold, making the UNIVAC the first commercial computer.

Second-Generation Computers

In the late 1950s, the transistor replaced vacuum tubes in the computer. A transistor could conduct electricity more quickly and efficiently than a vacuum tube. It was more reliable, too. Vacuum tubes often "burned out" and needed to be replaced. Transistors rarely needed to be replaced. A transistor was also much smaller than a vacuum tube, and it did not get hot.

When companies started building computers with transistors instead of vacuum tubes, the computers became smaller. They also solved problems ten times faster than first-generation computers.

It is difficult to give credit to any one person for building a secondgeneration computer. These computers were so complex that it took many people with many different skills to design all the computer parts. Several large companies built these second-generation computers. Some were for their own use. Some were sold to other companies.

Third-Generation Computers

In 1964, tiny integrated circuits were developed to take the place of transistors. These tiny circuits were even faster and more reliable than transistors. Integrated circuits, or IC's, were very small. They took up very little space.

Firstand second-generation computers were large machines. They stood on the floor and occupied a lot of space. But the third-generation computers were much smaller. Some could even sit on top of a table. Also, they could

32

operate 100 times faster than second-generation computers (1000 times faster than first-generation computers!)

Integrated circuits were mass-produced at a low cost. So, as more computers were built with integrated circuits, the price of computers dropped lower and lower. Third-generation computers were inexpensive enough and small enough to be bought by thousands of companies around the world.

Fourth-Generation Computers

In the mid-1970s, scientists developed a method of putting thousands of integrated circuits on one tiny silicon chip. The chip itself is so small that it can fit through the eye of a needle. It is difficult to imagine so many circuits on such a tiny surface. It takes many delicate instruments and special scientific techniques to create this "miracle" chip, called an integrated circuit chip.

Integrated circuit chips, or ICCs, are smaller and less expensive than the integrated circuits used in third-generation computers. So, the fourth-generation of computers are even smaller and less expensive than the third-generation computers. Computers built with these chips can perform over 10 million calculations in one second. They are 10 times faster than third-generation computers. (That's 1000 times faster than second-generation computers and 10,000 times faster than first-generation computers!)

As you can see, each generation of computers used a new invention to conduct the electricity through the computer. As the new electrical devices got smaller, the computers got smaller. They became more powerful than the earlier, large computers. They also became less expensive, which enabled small companies, schools, and people to buy their own computers.

Future Generations of Computers

What will future generations of computers be like? Computers will respond to a human voice, rather than ordinary input devices such as a keyboard, tape recorder, or disk drive. There are already some computers which can

33

"understand" a small spoken vocabulary. Some computers can "speak" certain sounds through voice synthesizers. These output units are being improved so that computers will be able to "talk" and sound almost human.

Scientists are already trying to fit millions of circuits on one chip. That will make computers even smaller and faster than they are now. Small pocketsize computers are already being sold. Some days, computers more powerful than today's will be as common and as small as tiny calculators.

From the time people counted on their fingers to the time world's first electromechanical computer was built, thousands of years went by. Yet, it took only thirty years from the invention of the big, expensive, and "slow" ENIAC, to the development of small, inexpensive, and fast microcomputers. What caused the rapid changes in those thirty years? New inventions usually open up new areas to explore. They bring about even more new inventions. This has been true with computers. Computers are used to design new computers. When a new and better computer has been built, it can be used to help design an even better computer. What will smaller, more powerful, less expensive computers mean to us? Perhaps, some day, there will be a computer in every home or in every student's school bag!

II. Answer the following questions:

1.Why are the improvements in computers taking place at a faster and faster rate?

2.What is the name of the world's first electromechanical computer?

3.What name is given to electronic computers that translate information into digits to store and process?

4.What devices were used to conduct electricity in the first-generation computers?

34