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Text II: Computers in the modern world
Almost everything in the modern world is done with the help of computers. Today, computers are used more and more extensively, because they are far more efficient than human beings. They have much better memories and can store great amount of information and they can do calculations very quickly. No man alive can do 500,000 sums in a second, but a modern computer can.
They can control machines, work out tomorrow’s weather, play chess, write poetry or compose music. They help students to find a book or article in many subjects. They can translate articles from foreign languages and make up many lists of information which are needed in a modern library.
Computers influence our life and our language. Today even a 5 years old child knows that a mouse is not only a type of small animal that has long front teeth, but also an input device, on top of which there are one or more buttons for communicating with the computer. But the only language computers can understand directly is called machine code. It consists of the binary code (1s and 0s). Machine code as means of communication is very difficult to write, so you need a special program to understand this language.
Basic languages, in which the program is similar to the machine code version, are known as low-level languages. To make the program easier to write and to overcome the problem of intercommunication between different types of machines, higher-level languages were developed such as BASIC, COBOL, FORTRAN, Pascal, Ada, C, Java and others. A higher-level language is a problem oriented programming language, whereas a low-level language is machine oriented. At present there is a tendency towards an even higher level of programming languages, which might be called specification languages, and an increasing use of software development tools. Scientists report to be already working on artificial intelligence and the next generation of computers will be able to understand human languages.
Another great achievement of the computer world is the Internet. It is a magnificent global network with millions of people and computers connected together. There they exchange an immeasurable amount of information, e-mails, news, resources and ideas. With a few touches of a keyboard a person can get access to materials in almost everywhere. The web is one of the best resources for the up-to-date information. It is a hypertext-based system by which you can navigate through the Internet. Hypertext is the text that contains links to other documents. A special program known as browser can help you to find news, pictures, virtual museums, electronic magazines and print Web pages. You can also click on keyboard or buttons that take you to other pages or other Web sites. This is possible because browsers understand hypertext markup language or code, a set of commands to indicate how a web page is formatted and displayed.
The Internet allows Video conferencing programs and television for home communications, shopping, banking and other interactive services. For example, e-commerce offers convenience to the buyers. They can visit the World Wide Web sites 24 hours a day and seven days a week to compare prices and make purchases, without having to leave their homes or offices. In some cases, consumers can immediately obtain a product or service, such as an electronic book, a music file, or computer software by downloading it over the Internet.
For long-distance or worldwide communications, computers are usually connected into a wide area network to form a single integrated network. Networks can be linked together by telephone lines or fibre-optic cables. Modern telecommunication systems use fibre-optic cables which require little physical space. They are safe as they don’t carry electricity, and they avoid electromagnetic interference.
Network on different continents can also be connected via satellites. Computers are connected by means of a modem to ordinary telephone lines or fibre-optic cables, which are linked to a dish aerial. Communication satellites receive and send signals on a transcontinental scale.
We interact with computers by entering instructions and data into them. After the information has been processed, we can see the result on the visual display unit or the monitor. The picture and the characters we see on the screen are made up of picture elements which are called pixels. The total number of pixels the display is divided in (both horizontally and vertically) is known as resolution. Sharp image and high resolution are obtained with large number of pixels, and when the number of pixels is small, the resolution is low. Thus, pixel density affects the quality of the image. The cathode ray tube of the monitor is similar to that of TV set. An electron beam inside the tube scans the screen and turns on or off the pixels that make up the image. In a color monitor the screen surface is coated with substances called phosphor materials are – one each for red, green and blue. A beam of electrons causes phosphor materials to give coloured light from which the picture is formed. Colour monitors are capable to display many different colours at the same time. Portable computers use a flat liquid-crystal display (LCD) instead of a picture tube.
Exercise 1: Answers the following questions:
1.Why are computers used more and more extensively?
2. What can computers do?
3. Is the machine code the only language computers can understand directly?
4. What programming languages can you name?
5. Is the Internet a magnificent global network with millions of people and computers connected together?
6. How does the Internet work?
7. What services can be used in the Internet?
8. Can you interact with computers? How?
9. What is a pixel?
10. What is resolution?
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