Types of electronic computers

Date: 2015-10-07; view: 473.

UNIT 8. TYPES OF ELECTRONIC COMPUTERS

X. Write a brief summary of the text (15 sentences).

I. Practise reading the following words:

electronic, retrieve, purpose, designed, products, alarms, automobile, fuel, versatile, injection, accept, vary, liquid, minicomputers, simultaneously, primarily, arrays, sophisticated, analogy, engineering, particularly, simulated, automation, employ, analysis, compares, rearranges, binary, advantages, intervention, accurate

II. Before reading the text try to answer these questions:

1. What types of computers do you know?

2. What parts are modern computers made up of?

3. What products can computers be found in?

III. Read and translate the following text:

A computer is an electronic device that can use a list of instructions, called a program, to perform calculations or to store, manipulate and retrieve information. Computers come in many sizes and shapes. According to tasks they perform, computers may be special-purpose or dedicated and general-purpose computers. Special-purpose computers are designed to perform specific tasks. 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 (monitoring speeds and settings),and automobiles (controlling fuel injection, heating and air conditioning and monitoring hundreds of electronic sensors).

General-purpose computers, such as personal and business computers, are much more versatile, because they can accept new sets of instructions. Each new set of instructions, or program, enables the same computer to perform a different type of operation. For example, one program lets the computer act like a word processor, another lets it manage inventories and another transforms it into a video game.

Computers vary widely in size, cost and computing power. Although some general-purpose computers are as small as pocket radios, the smallest class of fully functional self-contained computers is the class called “notebook” computers. These usually consist of a CPU, data storage device called disk drives, a liquid-crystal display (LCD) and a full-size keyboard - all housed in a single unit small enough to fit into a briefcase.

Minicomputers are fast computers that have greater data manipulating capabilities than personal computers and can be used simultaneously by many people. These machines are primarily used by larger businesses to handle extensive accounting, billing and inventory records. Mainframes are large, extremely fast, multi-user computers that often contain complex arrays of processors, each designed to perform a specific function. Because they can handle huge databases, can simultaneously accommodate scores of users and can perform complex mathematics operations, they are mainstay of industry, research and university computing centers.

The speed and power of supercomputers, the fastest class of computers, are almost beyond human comprehension and their capabilities are continually being improved. The most sophisticated of these machines can perform nearly 32 billion calculations per second, store a billion characters in memory at one time, and do in hour what a desktop computer would take 40 years to do. Because these computers can cost millions of dollars, they are used primarily by government agencies and large research centers.

The three basic types of computers are digital, analog and hybrid. They differ from one another in terms of operating principle, equipment, design and application. The analog computer operates on data represented by continuously varying qualities, such as angular position or voltages, and provides a physical analogy of the mathematical problem to be solved. The simplest analog calculating device is the slide rule. The following principal units make up an analog computer:

1) a calculating device;

2) a controlling device;

3) a generator;

4) a plug board;

5) an output device.

Capable of solving ordinary differential equations, the analog computer is well suited for use in systems engineering, particularly for implementing real-time simulated models of processes and equipment. Another common application is the analysis of networks, such as those for electric-power distribution. This type of computers is widely used in automation and in aviation. Many air-borne control systems such as the autopilot employ an analog computer.

Unlike the analog computer which operates on continuous variables, the digital computer works with data in discrete form, i.e., expressed directly as the digits of the binary code. It counts, lists, compares, and rearranges these binary digits of data in accordance with very detailed program instructions stored within its memory.

Modern digital computers are made up of the following components:

1) a central processing unit (CPU);

2)input devices;

3) memory storage devices;

4) output devices;

5) a communications network, called a “bus”, that links all the elements of the system and connects the system to the external world.

Digital computers can be programmed to perform a host of varied tasks. They are used for electronic data processing, they are widely used in the solution of the problems of science, engineering, business. This use is based on their ability to operate at a great speed, to produce accurate results, to store large quantities of information and to carry out a long sequence of operations without human intervention. As a consequence, more than 90 percent of the computers in use today are of this type.

The hybrid computer combines the characteristics and advantages of analog and digital systems; it offers greater precision than the former and more control capability than the latter. Equipped with special conversion devices, it utilizes both analog and discrete representation of data.

In recent years hybrid systems have been used in simulation studies of nuclear-power plants, guided-missle systems and spacecraft in which a close representation of a dynamic system is essential.

IV. Answer the following questions:

1. What are computers used for?

2. How can computers be classified?

3. What is the fastest class of computers?

4. What computers are much more versatile?

5. What do analog computers operate on?

6. Where are analog computers used in?

7. What does the hybrid computer offer?

8. What do computers vary widely in?

V. Agree or disagree with the following statements:

1. Minicomputers can be used simultaneously by many people.

2. Digital computers operate on continuous variables.

3. Mainframes often contain complex arrays of processors.

4. General-purpose computers are much more versatile because they can accept new sets of instructions.

5. Supercomputers can perform nearly 32 billion calculations per minute.

VI. Find in the text the English equivalents to the following Ukrainian word-combinations:

атомна електростанція, звичайне диференціальне рівняння, комп'ютер спеціального призначення, системотехніка, незалежний комп'ютер, може забезпечувати одночасну роботу багатьох користувачів, конденціонування повітря, кутове положення, як наслідок, виконувати послідовність операцій, багато процесорів, величини, що неперервно змінюються, вприскування палива, вміститись в портфелі, проводити широкомасштабний бухгалтерський облік, багато різноманітних завдань, людська уява, комутаційне поле, логарифмічна лінійка

VII. Which words in the text have the same meaning as:

make/do, dedicated, keep/hold, clocks, important, information, feature, propose, broadly, named, vary, general, kind, use, velocity, big, quick, at the same time, every, differ, for instance

VIII. Here are the answers, make out the questions:

1. an electronic device;

2. in different electronic products;

3. a host of varied tasks;

4. of analog and digital systems;

5. by government agencies and large research centers;

6. digital, analog and hybrid computers;

7. the analysis of network.

IX. Choose the correct form of the verb or the correct preposition:

1. A computer is an electronic device that _____ a list of instructions to perform calculations.

a) use b) are used c) is used d) uses

2. Special-purpose computers _____ to perform specific tasks.

a) are designed b) are to design c) are designing d) will be designed

3. Special purpose computers can be _____ in thousands of electronic products.

a) find b) finding c) founded d) found

4. Minicomputers _____ to handle extensive accounting, billing, etc.

a) are used b) will have been used c) is used d) was used

5. The results of these arithmetic and logic operations are translated into characters that can be readily _____ by the human operator.

a) understand b) understanding c) understood d) understands

6. Most CPU chips and microprocessors _____ four functional sections.

a) has b) will have c) had d) have

7. Digital computers can _____ programmed to perform a host of varied tasks.

a) to be b) be c) have been d) being

8. The hybrid computer _____ the characteristics and advantages of analog and digital systems.

a) combines b) will be combined c) is combining d) combine