Unit VIII computers

Part I

I. Match the computer parts with the words below:

a) CD-drive b) disk drive с) keyboard d) modem e) monitor f) mouse

g) printer h) speakers

II. Make a list of people who use computers. What do they use them for?

III. Read the text Personal computers and circle the information that is not mentioned in the text.

1) size of computers

2) speed of operation

3) development of computers

4) a computer system

5) price of computers

6) changes in our lives due to computers

7) different types of computers

8) attraction of computers

9) our dependence on computers

10) greater cooperation between banks and on-line services

Personal computers

A computer is any device that can perform numerical calculations. The term usually refers to an electronic device that can perform automatically a series of tasks according to a set of instructions. The set of instructions is called a program, and the tasks may include making arithmetic calculations, storing, and processing data, controlling another device, or interacting with a person to perform a business function or to play a video game.

Computations that once required machines that weighed 30 tons and occupied warehouse-size rooms can now be done by computers that weigh less than five ounces (140 grams) and can fit in a suit pocket or a purse. The “brains” of today's computers are integrated circuits (ICs), sometimes called microchips, or simply chips. They can each contain hundreds of millions of microscopic electronic components and are designed for many specific operations. Some chips make up a computer's central processing unit (CPU), which controls the computer’s overall operation; some are math coprocessors that can perform millions of mathematical operations per second; and others are memory chips that can each store billions of characters of information at one time.

In 1953 there were only about 100 computers in use in the entire world. Today billions of computers form the core of electronic products, and programmable computers are being used in homes, schools, businesses, government offices, and universities for almost every purpose.

Computers come in many sizes and shapes. Special-purpose, or dedicated, computers are designed to perform specific tasks. Their operations are limited to the programs built into their microchips. These computers are the basis for electronic calculators and can be found in thousands of other electronic products, including digital watches (controlling timing, alarms, and displays), cameras and automobiles (controlling fuel injection, heating, and air-conditioning and monitoring hundreds of electronic sensors).

General-purpose computers, such as personal computers and business computers, are much more versatile because they can accept new programs. Each new program enables the same computer to perform a different set of tasks. For example, one program instructs the computer to be a word processor, another instructs it to manage inventories, and another transforms it into a video game.

Today’s PCs can perform several billion operations per second. These computers are used not only for household management and personal entertainment, but also for most of the automated tasks required by small businesses.

Servers are fast computers that have greater data-processing capabilities than most PCs and workstations and can be used simultaneously by many people. Often several PCs and workstations are connected to a server via a local area network (LAN). The server controls resources that are shared by the people working at the PCs and workstations. An example of a shared resource is a large collection of information called a database.

The speed and power of supercomputers, the fastest class of computer, are almost beyond human comprehension, and their capabilities are continually being improved. The fastest of these machines can perform many trillions of operations per second on some type of calculations and can do the work of thousands of PCs. Supercomputers have these speeds through the use of several advanced engineering techniques. For example, critical circuitry is supercooled to a temperature of nearly absolute zero so that electrons can move at the speed of light, and many processing units are linked in such a way that they can all work on a single problem simultaneously. Because these computers can cost billions of dollars and because they can be large enough to cover the size of two basketball courts they are used primarily by government agencies and large research centers.

Researchers are currently developing microchips called digital signal processors (DSPs) to enable computers to recognize and interpret human speech. This development promises to lead to a revolution in the way humans communicate and transfer information.

Computers make all modern communications possible. They operate telephone switching systems, coordinate satellite launches and operations, help generate special effects for movies, and control the equipment in television and radio broadcasts. Local area networks link the computers in separate departments of businesses or universities, and the Internet links computers all over the world. Journalists and writers use word processors to write articles and books, which they then submit electronically to publishers.

Scientists and researchers use computers in many ways to collect, store, manipulate, and analyze data. Running simulations is one of the most important applications. Data representing a real-life system is entered into the computer, and the computer manipulates the data in order to show how the natural system is likely to behave under a variety of conditions. In this way scientists can test new theories and designs or can examine a problem that does not lead itself to direct experimentation. Computer-aided design (CAD) programs enable engineers and architects to design three-dimensional models on a computer screen. Chemists may use computer simulations to design and test molecular models of new drugs.

Computers have opened a new era in manufacturing and consumer-product development. In factories, computer-assisted manufacturing (CAM) programs help people plan complex production schedules, keep track of inventories and accounts, run automated assembly lines, and control robots. Dedicated computers are routinely used in thousands of products ranging from calculators to airplanes.

Government agencies are the largest users of mainframes and supercomputers. Computers are essential for compiling census data, handling tax records, maintaining criminal records, and other administrative tasks. Governments also use supercomputers for weather research, interpreting satellite data, weapons development, and cryptography.