Computer English Unit 1 Computer and Computer Science(计算机英语 第一单元 计算机与计算机科学)

Unit1 Computer and Computer Science

第一单元：计算机与计算机科学

Section A:

A节：

Computer Overview

计算机概览

Introduction

一、引言

A computer is an electronic device that can receive a set of instructions, or program, and then carry out this program by performing calculations on numerical data or by manipulating other forms of information.

计算机是一种电子设备，它能接收一套指令或一个程序，然后通过对数字数据进行运算或对其他形式的信息进行处理来执行该程序。

The modern world of high technology could not have come about except for the development of the computer.

要不是由于计算机的发展，现代的高科技世界是不可能产生的。

Different types and sizes of computers find uses throughout society in the storage and handling of data, from secret governmental files to banking transactions to private household accounts.

不同类型和大小的计算机在整个社会被用于存储和处理各种数据，从保密政府文件、银行交易到私人家庭账目。

Computers have opened up a new era in manufacturing through the techniques of automation, and they have enhanced modern communication systems.

计算机通过自动化技术开辟了制造业的新纪元，而且它们也增强了现代通信系统的性能。

They are essential tools in almost every field of research and applied technology, from constructing models of the universe to producing tomorrow’s weather reports, and their use has in itself opened up new areas of conjecture.

在几乎每一个研究和应用技术领域，从构建宇宙模型到产生明天的气象报告，计算机都是必要的工具，并且它们的应用本身就开辟了人们推测的新领域。

Database services and computer networks make available a great variety of information sources.

数据库服务和计算机网络使各种各样的信息源可供使用。

The same advanced techniques also make possible invasions of personal and business privacy.

同样的先进技术也使侵犯个人隐私和商业秘密成为可能。

Computer crime has become one of the many risks that are part of the price of modern technology.

计算机犯罪已经成为作为现代技术代价组成部分的许多风险之一。

History

二、历史

The first adding machine, a precursor of the digital computer, was devised in the 1642 by the French scientist, mathematician, and philosopher Blaise Pascal.

第一台加法机是法国科学家、数学家和哲学家布莱斯·帕斯卡于1642年设计的，它是数字计算机的先驱。

This device employed a series of ten-toothed wheels, each tooth representing a digit from 0 to 9.

这个装置使用了一系列带有10个齿的轮子，每个齿代表从0到9的一个数字。

The wheels were connected so that numbers could be added to each other by advancing the wheels by a correct number of teeth.In the 1670s the German philosopher and mathematician Gottfried Wilhelm Leibniz improved on this machine by devising one that could also multiply.

轮子互相连接，从而通过按照正确的齿数向前转动轮子，就可以将数字彼此相加。17世纪70 年代，德国哲学家和数学家戈特弗里德·威廉·莱布尼兹对这台机器进行了改良，设计了一台也能做乘法的机器。

The French inventor Joseph-Marie Jacquard, in designing an automatic loom, used thin, perforated wooden boards to control the weaving of complicated designs.

法国发明家约瑟夫―玛丽·雅卡尔，在设计自动织机时，使用了穿孔的薄木板来控制复杂图案的编织。

During the 1880s the American statistician Herman Hollerith conceived the idea of using perforated card, similar to Jacquard’s boards, for processing data.

在19世纪80年代期间，美国统计学家赫尔曼·何勒里斯，想出了使用类似雅卡尔的木板那样的穿孔卡片来处理数据的主意。

Employing a system that passed punched cards, over electrical contacts, he was able to compile statistical information for the 1890 United States census.

通过使用一种将穿孔卡片从电触点上移过的系统，他得以为1890年的美国人口普查汇编统计信息。

The Analytical Engine

1、分析机

Also in the 19th century, the British mathematician and inventor Charles Babbage worked out the principles of the modern digital computer.

也是在19世纪，英国数学家和发明家查尔斯·巴比奇，提出了现代数字计算机的原理。

He conceived a number of machines, such as Difference Engine, that was designed to handle complicated mathematical problems.

他构想出旨在处理复杂数学题的若干机器，如差分机。

Many historians consider Babbage and his associate, the mathematician Augusta Ada Byron, the true pioneers of the modern digital computer.

许多历史学家认为，巴比奇及其合伙人，数学家奥古斯塔·埃达·拜伦，是现代数字计算机

的真正先驱。

One of Babbage’s designs, the Analytical Engine, had many features of a modern computer.

巴比奇的设计之一，分析机，具有现代计算机的许多特征。

It had an input stream in the form of a deck of punched cards, a “store” for saving data, a “mill” for arithmetic operations, and a printer that made a permanent record.它有一个以一叠穿孔卡片的形式存在的输入流、一个保存数据的“仓库”、一个进行算术运算的“工厂”和一个产生永久性纪录的打印机。

Babbage failed to put this idea into practice, though it way well have been technically possible at that date.

巴比奇未能将这个想法付诸实践，尽管在那个时代它在技术上很可能是可行的。

2. Early Computers

2、早期的计算机

Analogue computer began to be built in the late 19th century.

模拟计算机是19世纪末开始制造的。

Early models calculated by means of rotating shafts and gears.

早期型号是靠转动的轴和齿轮来进行计算的。

Numerical approximations of equations too difficult to solve in any other way were evaluated with such machine.

用任何其他方法都难以计算的方程近似数值，可以用这样的机器来求得。

Lord Kelvin built a mechanical tide predictor that was a specialized analogue computer. 开尔文勋爵制造了一台机械潮汐预报器，这实际上就是一台专用模拟计算机。

During World War 1 and 2, mechanical and later, electrical analogue computing systems were used as torpedo course predictors in submarines and as bombsight controllers in aircraft.

第一次和第二次世界大战期间，机械模拟计算系统，以及后来的电动模拟计算系统，在潜艇上被用作鱼雷航线预测器，在飞机上被用作轰炸瞄准器的控制器。

Another system was designed to predict spring floods in the Mississippi River basin. 有人还设计了另一个系统，用于预测密西西比河流域春天的洪水。

3. Electronic Computers

3、电子计算机

During World War 2, a team of scientists and mathematicians, working at Bletchley Park, north of London, created one of the first all-electronic digital computers: 第二次世界大战期间，以伦敦北面的布莱切利公园为工作地点的一组科学家和数学家，制造了最早的全电子数字计算机之一：

Colossus.

“巨人”。

By December 1943, Colossus, which incorporated 1500 vacuum tubes, was operational. 到1943年12月，这个包含了1500个真空管的“巨人”开始运转了。

It was used by the team headed by Alan Turing, in the largely successful attempt to

crack German radio messages enciphered in the Enigma code.

它被以艾伦·图灵为首的小组用于破译德国用恩尼格码加密的无线电报，他们的尝试大部分是成功的。

Independently of this, in the United States, a prototype electronic machine had been built as early as 1939, by John Atanasoff and Clifford Berry at Iowa State College. 除此而外，在美国，约翰·阿塔纳索夫和克利福德·贝里早在1939年就在艾奥瓦州立学院制造了一台原型电子机。

This prototype and later research were completed quietly and later overshadowed by the development of the Electronic Numerical Integrator And Computer (ENIAC) in 1945. 这台原型机和后来的研究工作都是悄悄完成的，而且后来因1945年电子数字积分计算机（ENIAC）的研制而显得相形见绌。

ENIAC was granted a patent, which was overturned decades later, in 1973, when the machine was revealed to have incorporated principles first used in the Atanasoff-Berry Computer.

ENIAC被授予了专利。但是，数十年后，在1973年，当该机被揭露吸收了在阿塔纳索夫―贝里计算机中首次使用的原理后，这项专利被废除了。

ENIAC contained 18000 vacuum tubes and had a speed of several hundred multiplications per minute, but originally its program was wired into the processor and had to be manually altered.

ENIAC含有18,000个真空管，具有每分钟几百次的乘法运算速度，但是，其程序最初是通过导线传送到处理器内的，必须由人工更改。

Later machines were built with program storage, based on the ideas of the Hungarian-American mathematician John von Neumann.

根据美籍匈牙利数学家约翰·冯·诺伊曼的想法，后来制造的机器带有一个程序存储器。The instructions, like the data, were stored within a “memory”, freeing the computer from the speed limitations of the paper-tape reader during execution and permitting problems to be solved without rewiring the computer.

指令像数据一样存储在“存储器”中，使计算机在执行过程中摆脱了纸带阅读器的速度限制，并使问题在不给计算机重新接线的情况下得以解决。

The use of the transistor in computers in the late 1950s marked the advent of smaller, faster, and more versatile logical elements than were possible with vacuum-tube machines.

20 世纪50年代末，晶体管在计算机中的应用，标志着比在真空管机器情况下体积小、速度快、用途广的逻辑元件的出现。

Because transistors use much less power and have a much longer life, this development alone was responsible for the improved machines called second-generation computers. 由于晶体管使用的功率小得多，寿命也长得多，仅这项发展本身就导致了被称之为第二代计算机的改良机器的产生。

Components became smaller, as did inter-component spacings, and the system became much less expensive to build.

元件变小了，元件的间距也变小了，而且系统的制造成本也变得低得多。

4. Integrated Circuits

4、集成电路

Late in the 1960s the integrated circuit, or IC, was introduced, making it possible for many transistors to be fabricated on one silicon substrate, with interconnecting wires plated in place.

20 世纪60年代末，集成电路得到采用，从而有可能将许多晶体管制作在一块硅衬底上，晶体管之间用覆镀在适当位置的导线相连接。

The IC resulted in a further reduction in price, size, and failure rate.

集成电路导致价格、尺寸和故障率的进一步降低。

The microprocessor became a reality in the mid-1970s with introduction of the large-scale integrated (LSI) circuit and later, the very large-scale integrated (VLSI) circuit (microchip), with many thousands of interconnected transistors etched into a single silicon substrate.

20世纪70年代中期，随着大规模集成电路和后来的超大规模集成电路（微芯片）的采用，成千上万个彼此相连的晶体管被蚀刻在一块硅衬底上，于是微处理器成为现实。

To return, then, to the switching capabilities of a modern computer:

那么，再回过头来看看现代计算机处理开关值的能力：

computers in the 1970s, were generally able to handle eight switches at a time. 20世纪70年代的计算机一般一次能够处理8个开关值。

That is, they could deal with eight binary digits, or bits, of data, at every cycle. 也就是说，在每个循环中，它们能处理8个二进制数字或位的数据。

A group of eight bits is called a byte, each byte containing 256 (2 to the 8th power) possible patterns of ONs and OFFs (or 1s and 0s).

8 个位为一组，称为一个字节；每个字节包含256（2的8次方）个开与关（或0与1）的可能模式。

Each pattern is the equivalent of an instruction, a part of an instruction, or a particular type of datum, such as a number or a character or a graphics symbol. 每个模式相当于一条指令、一条指令的一部分或者一个特定的数据类型，如一个数字、一个字符或一个图形符号。

The pattern 11010010, for example, might be binary data—in this case, the decimal number 210—or it might be an instruction telling the computer to compare data stored in its switches to data stored in a certain memory—chip location.

例如，11010010这个模式可能是二进制数据——在此情况下代表210这个十进制数字，或者它可能是一条指令，告诉计算机将存储在其交换设备中的数据与存储在存储芯片某个位置的数据进行比较。

The development of processors that can handle 16, 32, and 64 bits of data at a time has increased the speed of computers.

一次能处理16、32和64位数据的处理器的研制，提高了计算机的速度。

The complete collection of recognizable patterns—the total list of operations–of which a computer is capable is called its instruction set.

一台计算机能够处理的全部可识别模式——操作总清单——称为其指令集。

Both factors—the number of bits that can be handled at one time, and the size of instruction sets—continue to increase with the ongoing development of modern digital computers.

随着现代数字计算机的不断发展，这两个因素——能够同时处理的位数和指令集的大小——在继续增长。

Hardware

三、硬件

Modern digital computers are all conceptually similar, regardless of size.

不论尺寸大小，现代数字计算机在概念上都是类似的。

Nevertheless, they can be divided into several categories on the basis of cost and performance:

然而，根据成本与性能，它们可分为几类：

the personal computer or microcomputer, a relatively low-cost machine, usually of desktop size (though “laptops” are small enough to fit in a briefcase, and “palmtops” can fit into a pocket); the workstation, a microcomputer with enhanced graphics and communications capabilities that make it especially useful for office work; the minicomputer, generally too expensive for personal use, with capabilities suited to a business, school, or laboratory; and the mainframe computer, a large, expensive machine with the capability of serving the needs of major business enterprises, government departments, scientific research establishments, or the like (the largest and fastest of these are called supercomputers).

个人计算机或微型计算机，一种成本较低的机器，通常只有桌面大小（尽管“膝上型计算机”小到能够放入公文包，而“掌上型计算机”能够放入口袋）；工作站，一种具有增强型图形与通信能力、从而使其对于办公室工作特别有用的微型计算机；小型计算机，一般就个人使用而言太昂贵，其性能适合于工商企业、学校或实验室；以及大型机，一种大型的昂贵机器，具有满足大规模工商企业、政府部门、科研机构或者诸如此类机构需要的能力（其中体积最大、速度最快的称为巨型计算机）。

A digital computer is not a single machine:

一台数字计算机不是单一的机器。

rather, it is a system composed of five distinct elements(1) a central processing unit; (2) input device;(3) memory storage devices;(4) output devices; and (5) a communication network, called a bus, which links all the elements of the system and connects the system to the external world.

确切地说，它是由5个不同的要素组成的系统：（1）中央处理器；（2）输入设备；（3）存储设备；（4）输出设备；以及（5）被称作总线的通信网络，它将系统的所有要素连接起来并将系统与外界连接起来。

Programming

四、编程

A program is a sequence of instructions that tells the hardware of a computer what operations to perform on data.

一个程序就是一系列指令，告诉计算机硬件对数据执行什么样的操作。

Programs can be built into the hardware itself, or they may exist independently in a form known as software.

程序可以内嵌在硬件本身里，或以软件的形式独立存在。

In some specialized, or “dedicated” computers, the operating instructions are embedded in their circuitry; common examples are the microcomputers found in calculators, wristwatches, car engines, and microwave ovens.

在一些专门或“专用”计算机中，操作指令被嵌入其电路里；常见的例子有计算器、手表、汽车发动机和微波炉中的微型计算机。

A general-purpose computer, on the other hand, although it contains some built-in programs (in ROM) or instructions (in the processor chip), depends on external programs to perform useful tasks.

另一方面，通用计算机尽管含有一些内置的程序（在只读存储器中）或者指令（在处理器芯片中），但依靠外部程序来执行有用的任务。

Once a computer has been programmed, it can do only as much or as little as the software controlling it at any given moment enables it to do.

计算机一旦被编程，就只能做在任何特定时刻控制它的软件所允许它做的事情。

Software in widespread use includes a wide range of applications programs—instructions to the computer on how to perform various tasks.

广泛使用的软件包括一系列各种各样的应用程序——告诉计算机如何执行各种任务的指令。

Future Developments

五、未来的发展

One continuing trend in computer development is microminiaturization, the effort to compress more circuit elements into smaller and smaller chip space.

计算机发展的一个持续不断的趋势是微小型化，亦即将越来越多的电路元件压缩在越来越小的芯片空间内的努力。

Researchers are also trying to speed up circuitry functions through the use of superconductivity, the phenomenon of decreased electrical resistance observed in certain materials at very low temperatures.

研究人员也在设法利用超导性来提高电路的功能速度。超导性是在超低温条件下在某些材料中观察到的电阻减小现象。

The “fifth-generation” computer effort to develop computers that can solve complex problems in ways that might eventually merit the description “creative” is another trend in computer development, the ideal goal being true artificial intelligence. 计算机发展的另一个趋势是“第五代”计算机的研制工作，亦即研制可以解决复杂问题而且其解决方法用“创造性的”这个词来形容或许最终名副其实的计算机，理想的目标是真正的人工智能。

One path actively being explored is parallel-processing computing, which uses many chips to perform several different tasks at the same time.

正在积极探索的一条道路是并行处理计算，亦即利用许多芯片来同时执行数个不同的任务。One important parallel-processing approach is the neural network, which mimics the architecture of the nervous system.

一种重要的并行处理方法是模仿神经系统结构的神经网络。

Another ongoing trend is the increase in computer networking, which now employs the worldwide data communications system of satellite and cable links to connect computers globally.

另一个不断发展的趋势是计算机联网的增加。计算机联网现在使用由卫星和电缆链路构成的世界范围的数据通信系统，来将全球的计算机连在一起。

There is also a great deal of research into the possibility of “optical” computers—hardware that processes not pulses of electricity but much faster pulses of light.

此外，大量的研究工作还投入在探索“光”计算机的可能性上——这种硬件处理的不是电脉冲而是快得多的光脉冲。