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1-3 Introduction to the History of Computers |
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It is hard to say exactly when the modern computer was invented.Starting in the 1930s and through the 1940s,a number of machines were developed that were like computers.But most of these machines did not have all the characteristics that we associate with computers today.These characteristics are that the machine is electronic,that it has a stored program,and that it is general purpose.
很难确切地说现代计算机是什么时候发明的。20世纪30—40年代，许多类似计算机的机器被开发出来。但是这些机器大部分没有今天我们所说的计算机的所有特征。这些特性是电子设备、具有储存的程序、具有通用性。
Introduction to the History of Computers
One of the first computerlike devices was developed in Germany in 1941.Called the Z3,it was a general-purpose,stored-program machine with many electronic parts,but it had a mechanical memory.Another electromechanical computing machine was developed by Howard Aiken,with financial assistance from IBM,at Harvard University in 1943.It was called the Automatic Sequence Control Calculator MarkⅠ,or simply the Harvard MarkⅠ.Neither of these machines was a true computer,however,because they were not entirely electronic.
Perhaps the most influential of the early computerlike devices was the Electronic Numerical Integrator and Computer,or ENIAC.It was developed by J.Presper Eckert and John Mauchly at the University of Pennsylvania.The project began in 1943 and was completed in 1946.The machine was huge;it weighed 30 tons and contained over 18' 000 vacuum tubes.
The ENIAC was a major advancement for its time.It was the first general-purpose,electronic computing machine and was capable of performing thousands of operations per second.It was controlled,however,by switches and plugs that had to be manually set.Thus,although it was a general-purpose electronic device,it did not have a stored program.Therefore,it did not have all the characteristics of a computer.
First-generation computers were characterized by the use of vacuum tubes as their principal electronic component.Vacuum tubes are bulky and produce a lot of heat,so first-generation computers were large and required extensive air conditioning to keep them cool.In addition,because vacuum tubes do not operate very fast,these computers were relatively slow.
In the second generation of computers,transistors replaced vacuum tubes.Although invented in 1948,the first all-transistor computer did not become available until 1959.Transistors are smaller and less expensive than vacuum tubes,and they operate faster and produce less heat.Hence,with second-generation computers,the size and cost of computers decreased;their speed increased,and their air-conditioning needs were reduced.
The technical development that marks the third generation of computers is the use of integrated circuits or ICs in computers.An integrated circuit is a piece of silicon(a chip)containing numerous transistors.One IC replaces many transistors in a computer,resulting in a continuation of the trends beginning in the second generation.These trends include reduced size,reduced cost,increased speed,and reduced need for air conditioning.
Although not everyone agrees that there is a fourth computer generation,those that do feel that it began in 1971,when IBM introduced its successors to the System /360 line of computers.These mainframe computers were called the System /370,and current-model IBM computers,although not called System /370s,evolved directly from these computers.
Software development during the fourth computer generation started off with little change from the third generation.Operating systems were gradually improved,and new languages were designed.Database software became widely used during this time.The most important trend,however,resulted from the microcomputer revolution.Packaged software became widely available for microcomputers so that today most software is purchased,not developed from scratch.
We may have defined our last generation of computers and begun the era of generationless computers.Even though computer manufacturers talk of “ fifth-” and“sixth-” generation computers,this talk is more a marketing play than a reflection of reality.
associate [əˈsouʃɪət] vt .联想
general-purpose adj .通用的
assistance [əˈsɪst(ə)ns] n .援助；帮助
influential [ˌɪnfluˈenʃl] adj .有影响的
advancement [ədˈvɑːnsmənt] n .先进
thousands of成千上万的
manually [ˈmænjʊəlɪ] adv.人工地
bulky [ˈbʌlki] adj .笨重的；庞大的；体积大的
transistor [trænˈzɪstə(r) ] n .晶体管
purchase [ˈpəːtʃəs] v.购买；采购
from scratch从头做起，从零开始
reflection [rɪˈflekʃn] n .反映
computerlike [kəmˈpjuːtə(r)laik] adj .计算机似的
result in导致；造成……结果
electromechanical [ɪˌlektrəʊmɪˈkænɪk(ə)l] adj .机电的；电机的
integrated circuits n.集成电路
Pennsylvania [pensɪlˈveɪnjə] n .宾夕法尼（美国）
vacuum tube真空管
air conditioning空气调节
mainframe [ˈmeinˌfreim] n .主机；大型机
1.The UNIVACⅠ was the first commercial computer in this generation.As noted earlier,it was used in the Census Bureau in 1951.It was also the first computer to be used in a business application.In 1954,General Electric took delivery of a UNIVACⅠ and used it for some of its business data processing.
2.Software also continued to develop during this time.Many new programming languages were designed,including COBOL in 1960.More and more businesses and organizations were beginning to use computers for their data processing needs.
3.The fourth generation of computers is more difficult to define than the other three generations.This generation is characterized by more and more transistors being contained on a silicon chip.First there was Large Scale Integration( LSI),with hundreds and thousands of transistors per chip,then came Very Large Scale Integration(VLSI),with tens of thousands and hundreds of thousands of transistors.The trend continues today.
Ⅰ. Choices.
1.How many generations of computers are introduced in this chapter?
A.3
B.4
C.5
D.6
2.The first computer's name is___.
A.MarkⅠ
B.IBM
C.ENIAC
D.6 System /360
3.The first-generation computers were characterized by the use of___.
A.integrated circuits
B.transistors
C.electronic machines
D.vacuum tubes
4.The second-generation computers were characterized by the use of___.
A.integrated circuits
B.transistors
C.electronic machines
D.vacuum tubes
5.The third-generation computers were characterized by the use of___.
A.integrated circuits
B.transistors
C.electronic machines s
D.vacuum tube
Ⅱ. Translate the following paragraph into Chinese.
Advocates of the concept of generationless computers say that even though technological innovations are coming in rapid succession,no single innovation is,or will be,significant enough to characterize another generation of computers.
Ⅲ. Translate the following paragraph into English.
许多新的编程语言被发明，包括1960年发明的COBOL。越来越多的企业和组织开始使用计算机以满足他们的数据处理需要。
计算机发展史
第一个类似计算机的装置之一是1941年由德国研制的，叫Z3,它是通用型储存程序机器，具有许多电子部件，但是它的存储器是机械的。另一台机电式计算机器是由霍华德·艾坎在IBM的资助下于1943年在哈佛大学研制的。它被称为自动序列控制计算器Mark Ⅰ，或简称哈佛MarkⅠ。然而，这些机器都不是真正的计算机，因为它们不是完全电子化的。
也许早期最具影响力的类似计算机的装置应该是电子数字积分计算机，或简称ENIAC。它是由宾夕法尼亚大学的J.Presper Eckert和John Mauchly研制的。该工程于1943年开始，并于1946年完成。这台机器极其庞大，重达30吨，而且包含18000多个真空管。
ENIAC是当时重要的成就。它是第一台通用型电子计算机器，并能够执行每秒数千次运算。然而，它是由开关和继电器控制的，必须手工设定。因此，虽然它是一个通用型电子装置，但是它没有储存程序。因此，它不具备计算机的所有特征。
第一代计算机的特色是使用真空管为其主要电子器件。真空管体积大且发热严重，因此第一代计算机体积庞大，并且需要大量的空调设备保持冷却。此外，因为真空管运行不是很快，这些计算机运行速度相对较慢。
在第二代计算机中，晶体管取代了真空管。虽然发明于1948年，但第一台全晶体管计算机直到1959年才成为现实。晶体管比真空管体积小、价格低，而且运行快且发热少。因此，随着第二代计算机的出现，计算机的体积和成本降低、速度提高，且它们对空调的需要减少。
作为第三代计算机标志的技术发展是在计算机中使用集成电路或简称IC。一个集成电路就是包含许多晶体管的一个（芯片）。一个集成电路代替了计算机中的许多晶体管，从而导致始于第二代的一些趋势继续存在。这些趋势包括计算机体积减小、成本降低、速度提高和对空调的需要减小。
虽然并不是每个人都同意存在一个第四代，那些认为存在的觉得它开始于1971年，其时IBM开发了System/360系列计算机的下一系列产品。这些大型计算机称为System/370,当前的IBM计算机虽然不叫作System/370,但都是从这些计算机直接发展而来的。
在计算机的第四代期间，软件的发展开始与第三代有所不同。操作系统在逐渐地改进，而新的语言被发明。期间数据库软件被广泛使用。然而，最重要的趋势起因于微型计算机革命。用于微型计算机的软件包随处可得，因此今天大多数的软件可以购得，而不需从头开始开发。
我们可能已经定义了我们最新一代计算机而且开始了计算机的无代时代。即使计算机制造商谈到“第五”和“第六”代计算机，这些说法更多是市场行为，而不是真实的反映。