Part 3. Programming

3. Раздел: Программирование

Unit 3.1. Computers: Introduction

3.1. Тема: Компьютеры: введение

Понятие компьютера. Аналоговые и цифровые компьютеры. Информатизация российского общества.

What is a Computer?

Понятие компьютера

E.x. 3.1.1. Прочитайте текст.

A computer is a general purpose device that can be programmed to carry out a finite set of arithmetic or logical operations. Since a sequence of operations can be readily changed, the computer can solve more than one kind of problem.

Conventionally, a computer consists of at least one processing element and some form of memory. The processing element carries out arithmetic and logic operations, and a sequencing and control unit that can change the order of operations based on stored information.

The first use of the word "computer" was recorded in 1613, referring to a person who carried out calculations, or computations, and the word continued with the same meaning until the middle of the 20th century. From the end of the 19th century the word began to take on its more familiar meaning, a machine that carries out computations Peripheral devices allow information to be retrieved from an external source, and the result of operations saved and retrieved.

Конец формы

We are all familiar with what a computer is in a specific, contemporary sense. Personal computers (PCs) are found in most aspects of daily life, and for some it is hard to even imagine a world without them. But the term means more than simply the Macs and PCs we are familiar with. A computer is, at its most basic, a machine which can take instructions, and perform computations based on those instructions.

It is the ability to take instructions — often known as programs — and execute them, that distinguishes a computer from a mechanical calculator. While both are able to make computations, a calculator responds simply to immediate input. In fact, most modern calculators are actually computers, with a number of pre-installed programs to help aid in complex tasks.

Computers range from the very small to the very large. Some are capable of doing millions of calculations in a single second, while others may take long periods of time to do even the most simple calculations. But theoretically, anything one computer is capable of doing, another will also be able to do. Given the right instructions, and sufficient memory, a computer found in a wristwatch should be able to accomplish anything a supercomputer can — although it might take thousands of years for the wristwatch to complete the operation.

At one time, computers were extremely large, and required enormous amounts of power. This made them useful only for a small amount of tasks — computing trajectories for astronomical or military applications, for example, or code breaking. Over time, with technological advances, they were scaled down and their energy requirements lowered immensely. This allowed the power to be harnessed for a staggering array of uses.

As prevalent as PCs are, they do not nearly begin to scratch the surface of computer use in our world. Interactive devices of all sorts contain their own computers. Cellular telephones, GPS units, portable organizers, ATM machines, gas pumps, and millions of other devices all make use of them to streamline their operations, and to offer features which would be impossible without one.

A computer like this is often referred to as an embedded computer. The embedded type is differentiated from a PC because it is essentially static in its function. While a PC, some cellular telephones, and some personal organizers are able to have new software installed, and make use of a wide range of features, an embedded computer usually has only a few purposes, which are relatively fixed once the device is manufactured.

Embedded systems vary in the amount of change that can happen to them after production. An MP3 player, for example, is an embedded computer, but can have quite a bit of interaction and changes made to it. It may allow the user to alter the colors used, change the clock, update firmware, and change the songs or playlists in memory. One within a traffic light, to take another example, is probably quite fixed. It is set to respond to a few certain programs — time of day, a trigger when a car approaches, and perhaps input from a central database in the case of more advanced systems. These programs are not built for interactivity, and will likely never be changed over the system’s life.

The computer is one of the most powerful innovations in human history. With their use, people are suddenly able to perform a staggering amount of computations at dazzling speeds. Information can be crunched, organized, and displayed in the blink of an eye. As technology continues to advance, the computer will no doubt become even more pervasive — and in many cases, likely even less recognizable.

E.x. 3.1.2. Выпишите из текста лексику профессиональной направленности на английском языке. Переведите слова на русский язык.

E.x. 3.1.3. Переведите первый абзац текста на русский язык.

E.x. 3.1.4. Выпишите из текста предложения, разъясняющие понятие «компьютер», переведите предложения на русский язык.

Analogue and Digital Computers Аналоговые и цифровые компьютеры

E.x. 3.1.5. Прочитайте текст.

The first electronic digital computers were developed between 1940 and 1945 in the United Kingdom and United States. Originally they were the size of a large room, consuming as much power as several hundred modern personal computers (PCs). In this era mechanical analog computers were used for military applications.

Modern computers based on integrated circuits are millions to billions of times more capable than the early machines, and occupy a fraction of the space. Simple computers are small enough to fit into mobile devices, and mobile computers can be powered by small batteries. Personal computers in their various forms are icons of the Information Age and are what most people think of as "computers". However, the embedded computers found in many devices from mp3 players to fighter aircraft and from toys to industrial robots are the most numerous.

Semiconductors and microprocessors

Computers using vacuum tubes as their electronic elements were in use throughout the 1950s, but by the 1960s had been largely replaced by semiconductor transistor-based machines, which were smaller, faster, cheaper to produce, required less power, and were more reliable. The first transistorised computer was demonstrated at the University of Manchester in 1953. In the 1970s, integrated circuit technology and the subsequent creation of microprocessors, such as the Intel 4004, further decreased size and cost and further increased speed and reliability of computers. By the late 1970s, many products such as video recorders contained dedicated computers called microcontrollers, and they started to appear as a replacement to mechanical controls in domestic appliances such as washing machines. The 1980s witnessed home computers and the now ubiquitous personal computer. With the evolution of the Internet, personal computers are becoming as common as the television and the telephone in the household

Modern smartphones are fully programmable computers in their own right, and as of 2009 may well be the most common form of such computers in existence

Programs

Replica of the Small-Scale Experimental Machine (SSEM), the world's first stored-program computer, at the Museum of Science and Industry in Manchester, England

The defining feature of modern computers which distinguishes them from all other machines is that they can be programmed. That is to say that some type of instructions (the program) can be given to the computer, and it will process them. While some computers may have strange concepts "instructions" and "output" (see quantum computing), modern computers based on the von Neumann architecture often have machine code in the form of an imperative programming language.

In practical terms, a computer program may be just a few instructions or extend to many millions of instructions, as do the programs for word processors and web browsers for example. A typical modern computer can execute billions of instructions per second (gigaflops) and rarely makes a mistake over many years of operation. Large computer programs consisting of several million instructions may take teams of programmers years to write, and due to the complexity of the task almost certainly contain errors.

E.x. 3.1.6. Выпишите из текста лексику профессиональной направленности. Переведите слова на русский язык.

E.x. 3.1.7. Дайте сравнительную характеристику аналоговых и цифровых компьютеров, пользуясь текстом.

Analogue Computers		Digital Computers
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E.x. 3.1.8. Переведите таблицу из упражнения 3.1.8. на русский язык.