《电子与通信工程专业英语》课件第17章

Unit17ComputerHardwareFundamentalsNEWWORDSANDPHRASES

NOTES

EXERCISES

参考译文

EXTENSIVETEXT

1.Thecentralprocessingunit

Thecentralprocessingunit(CPU)istheheartofthecomputersystems.Amongotherthings,itsconfigurationdetermineswhetheracomputerisfastorslowinrelationtoothercomputers.TheCPUisthemostcomplexcomputersystemcomponent,responsiblefordirectingmostofthecomputersystemactivitiesbasedontheinstructionsprovided.Asonecomputergenerationhasevolvedtothenext,thephysicalsizeoftheCPUhasoftenbecomesmallerandsmaller,whileitsspeedandcapacityhaveincreasedtremendously.Indeed,thesechangeshaveresultedinmicrocomputersthataresmallenoughtofitonyourdeskoryourlap.

TheCPUcomprisesthecontrolunitandthearithmetic/logicunit(ALU).

Thecontrolunitisresponsiblefordirectingandcoordinatingmostofthecomputersystemsactivities.Itdeterminesthemovementofelectronicsignalsbetweenmainmemoryandthearithmetic/logicunit,aswellasthecontrolsignalsbetweentheCPUandinput/outputdevices.

Justasacarisuselesswithoutgas,acomputerisnotmuchgoodwithoutsoftwareinstructions.Whenweusesoftware,weareworkingwithhighlevelinstructionsthataretobecarriedoutbythecontrolunit.Theseinstructionsareconvertedbyalanguageprocessorintoalowlevelformofinstructionsthatthecomputercanworkwithmachinelanguage,theonlylanguagethattheCPUcanunderstand.Inmachinelanguage,dataandinstructionsarerepresentedinbinaryform(0sand1s).Oncetheinstructionshavebeenconvertedintothisform,theycanberetrievedfrommainmemoryandinterpretedbythecontrolunit.Accordingtoeachspecificinstruction,thecontrolunitissuesthenecessarysignalstoothercomputersystemcomponentsasneededtosatisfytheprocessingrequirements[1].Thiscouldinvolve,forexample,directingthatdataberetrievedfromadiskstoragedevice,“telling”theprintertoprinttheletteryoujustwrote,orsimplydirectingthearithmetic/logicunittoaddtwonumbers[2].

WithouttheALU,computerswouldnotbeabletodomostofthetasksthatwefinduseful.TheALUperformsallthearithmeticandlogicalfunctionsthatis,itadds,subtracts,multiplies,divides,anddoescomparisons.Thesecomparisons,whicharebasically“lessthan”,“greaterthan”,and“equalto”,canbecombinedintoseveralcommonexpressions,suchas“greaterthanorequalto”.Theobjectiveofmostinstructionsthatusecomparisonsistodeterminewhichinstructionshouldbeexecutednext.

TheALUcontrolsthespeedofcalculationsandsoreceivesagreatdealofattentionfromcomputerusers.Oldermicrocomputers’speedsareusuallymeasuredinmilliseconds(1thousandthofasecond).Newermicrocomputers’speedsaremeasuredinnanoseconds(1billionthofasecond).Ifananosecondwereequaltooneminute,thenaminutewouldbeequalto1900years!

2.Computerhardware

Computerhardwarecanbedividedintofourcategories:inputhardware,storagehardware,processinghardware,andoutputhardware.

1)

Inputhardware

Thepurposeofinputhardwareistocollectdataandconvertitintoaformsuitableforcomputerprocessing.Themostcommoninputdeviceisakeyboard.Itlooksverymuchlikeatypewriterkeyboard.Itskeysarearrangedinthetypicaltypewriterlayout.Therearealsoanumberofadditionalkeys.Theycanbeusedtoenterspecialcomputerrelatedcodes.Althoughitisn’ttheonlytypeofinputdeviceavailable,thecomputerkeyboardistheonethatismostgenerallyusedbythebusinesscommunity.

2)

Storagehardware

Thepurposeofstoragehardwareistoprovideameansofstoringcomputerinstructionsanddatainaformthatisrelativelypermanent,thatis,thedataisnotlostwhenthepoweristurnedoffandeasytoretrievewhenneededforprocessing.Storagehardwarestoresdataaselectromagneticsignalsorlaseretchedspot,commonlyondiskortape,ratherthanonpaper.

3)

Processinghardware

Thepurposeofprocessinghardwareistoretrieve,interpret,anddirecttheexecutionofsoftwareinstructionsprovidedtothecomputer.ThemostcommoncomponentsofprocessinghardwarearetheCPUandmainmemory.

TheCPUisthebrainofthecomputer.Itreadsandinterpretssoftwareinstructionsandcoordinatestheprocessingcoordinateactivitiesthatmusttakeplace.ThedesignoftheCPUaffectstheprocessingpowerandspeedofthecomputer,aswellastheamountofmainmemoryitcanuseeffectively.WithawelldesignedCPUinyourcomputer,youcanperformhighlysophisticatedtasksinaveryshorttime.

Mainmemory(alsocalledinternalmemory,primarystorage,orjustmemory)canbethoughtofasanelectronicdesktop.Themoredesksurfaceyouhaveinfrontofyou,themoreyoucanplaceonit.Similarly,ifyourcomputerhasalotofmemory,youcanplacemoresimplesoftwareinstructionorsophisticatedsoftware;acomputerwithalargememoryismorecapableofholdingthethousandsofinstructionthatarecontainedinthemoresophisticatedsoftwareprograms.Alargememoryalsoallowsyoutoworkwithandmanipulategreatamountsofdataandinformationatonemanipulatetime.

4)

Outputhardware

Thepurposeofoutputhardwareistoprovidetheuserwillthemeanstoviewinformationproducedbythecomputersystem.Informationisoutputineitherhardcopyorsoftcopyform.Hardcopyoutputcanbeheldinyourhandexamplesarepaperwithtext(wordsornumbers)orgraphicsprintedonit.Softcopyoutputisdisplayedonamonitor,atelevisionlikescreenonwhichyoucanreadtextandgraphics.

3.Monitorandsystemunit

1)

Monitor

Thetermmonitorisusedinterchangeablywithscreen,videodisplayscreen,andcathoderaytube(CRT).Thisoutputdeviceprovidesyourprincipalvisualcontactwiththemicrocomputersystem.Whenyouentercommandsordatafromthekeyboard,youseetheresultsonthemonitor.Acolormonitor,oftenreferredtoasanRGB(forred,green,blue)monitor,candisplaytextandgraphicsinvariouscolors.Mostofthecapabilitiesofthemonitor,includingimageclarityandtheabilitytodographics,aredeterminedbythesophisticationofthevideodisplaycircuitboard,ifany,containedwithinthesystemunit.Inanycase,theuserneedstheappropriatesoftwaretotakeadvantageofamonitor’scapabilitiesincludingtheabilitytodisplaygraphics.

2)

Systemunit

Themaincomputersystemcabinet,calledthesystemunit,usuallyhousesthepowersupply,thesystemboard,andthestoragedevices(althoughsomestoragedevicesdiskdrives,forexampleareoftenhousedincabinetsoutsidethesystemunit).Theseelementscanbedefinedasfollows:

(1)

Thepowersupplyprovideselectricalpowertoallcomponentshousedinthesystemunit.Insomemicrocomputers,italsoprovidespowertothemonitor.

(2)

Thesystemboard,alsoknownasthemotherboard,isthemaincircuitboardofthemicrocomputersystem.Itnormallyincludes①themicroprocessorchip;②mainmemorychips;③allrelatedsupportcircuitry,and④theexpansionslotswhereadditionalcomponentscanbepluggedin.

(3)

Thestoragedevicesareusuallyoneormorefloppydiskdrivesandhighcapacityharddiskdrives.Afloppydisk,ordiskette,isathinplasticdiskenclosedinapaperorplasticcoveringthatcanbemagneticallyencodedwithdata.Harddisksarerigiddiskscapableofstoringmuchmoredatathanafloppydisk.(Andharddiskdrivesaccessdatafasterthanfloppydiskdrivesdo.)Harddisksaremoreexpensivethanfloppydisks.Sincemostharddisksarepermanentlyinstalledinthesystemunit,floppydisks,whichcanbecarriedaround,areoftenusedtomovedatafromonecomputertoanother.

(4)

Additionalcomponents:Theexpansionslotsonthesystemboardallowuserstoaddnewcomponentstotheircomputersystem.Themostpopularaddoncomponentincludes:①amemorycardcontainingmainmemorychipsthatgiveyouadditionalmainmemory;②aninternalmodemtofacilitatedatacommunicationbetweencomputersoverphonelinesandsimilarcables;③abatterypoweredclockandcalendarmechanism;④additionalprinterportsthatallowyoutocommunicatewithseveraltypesofoutputdevices;and⑤videodisplayboards.

4．RAMandROM

Therearetwowellknowntypesofmemorychips.OnetypeiscalledRAM.TheothertypeisROM.

1)

RAM

RAM(randomaccessmemory)chipsholdtheprogramanddatathattheCPUispresentlyprocessing.Thatis,itistemporaryorvolatilestorage.

TheprincipalfunctionofRAMistohold:①Dataforprocessing;②Instructionsforprocessingthedatathatis,theprogram;③Informationthatis,processeddatawaitingtobeoutputorsenttosecondarystoragesuchasafloppydiskinadiskdrive.

OneofthemostimportantfactstoknowaboutRAMisthatthepartofitscontentisheldonlytemporarily.Inotherwords,itisstoredonlyaslongasthemicrocomputeristurnedon.Whenyouturnthemachineoff,thecontentsimmediatelyvanish.Thestoredcontentsinmemoryarevolatileandcanvanishveryquickly,asduringapowerfailure[3].Itisthereforeagoodpracticetorepeatedlysaveyourworkinprocesstosecondarystoragemediumsuchasfloppydiskorharddisk.

Thenextimportantfacttoknowaboutmemoryisthatitscapacity.ThebanksofRAMchips(agroupofchips,usuallynine,arrangedinarow)[4]aresometimesonamemoryexpansioncard,whichfitsinsidethesystemcabinetandsometimesareonthemaincircuitboard.TheamountofdatathatcanbestoredinRAMismeasuredinbytes.MostdesktopPCssoldtodayhaveabout1GBofRAMandallowtheadditionofmorememory.TwotypesofmemoryareusedtoincreaseRAMexpandedmemoryandextendedmemory.Thetypeusedisinfluencedbythesophisticationofmicroprocessorinyourmachine.

2)

ROM

Howdoesyourcomputerknowwhattodowhenyouturniton?Howdoesitknowtocheckoutyourhardwarecomponents(suchasthekeyboardorthemonitor)toseethattheyhavebeenconnectedcorrectly?Instructionstoperformsuchoperations,whicharecriticaltotheoperationofcomputer,arestoredpermanentlyonareadonlymemory(ROM)chipinstalledbythemanufacturerinsidethecomputer.TheROMchipretainsinstructionsinapermanentlyaccessible,nonvolatileform.Whenthepowerinthecomputeristurnedoff,theinstructionsstoredinROMwillnotbelost.

CertaintypesofROMchipgiveusersaddedflexibility.Programmablereadonlymemory(PROM)chipsallowyoutoputyourowndataandprogramsonthem.Erasableprogrammablereadonlymemory(EPROM)chipscanbechangedbyusingaspecialultravioletlightdevice;however,youhavetotakeEPROMchipsoutofthecomputertochangethedataandprogramsonthem.Electricallyerasableprogrammablereadonlymemory(EEPROM)chipscanbechangedwithouttakingthemoutofthecomputer.

NEWWORDSANDPHRASES

configuration n. 构造，结构，配置

tremendously adv. 非常地

microcomputer n. 微(型)计算机

lap n. 膝盖

coordinate n. 坐标(系)；协同，协调；交叉索引；并列

binary adj. 二进制的

millisecond n. 毫秒

typewriter n. 打字机

etched adj. 被腐蚀的，被蚀刻的，风化的

interchangeably adv. 可交替地

diskette n. 磁盘

volatile adj. 可变的，不稳定的

exterior adj. 外部的

n. 外部

archive vt. 存档

n. 档案文件

spin vt.,vi. 旋转，纺，纺纱

n. 旋转

cursor n. 光标游标；指针，指示器

pixel n. 像素

dotmatrix 点阵

inkjet 墨水喷射,喷墨

thermal adj. 热的，热量的

NOTES

[1]Accordingtoeachspecificinstruction,thecontrolunitissuesthenecessarysignalstoothercomputersystemcomponentsasneededtosatisfytheprocessingrequirements.

本句可译为：针对每条特定的指令，控制单元向计算机系统其他部件发出必要的控制信号，以满足处理需求。

[2]Thiscouldinvolve,forexample,directingthatdataberetrievedfromadiskstoragedevice,“telling”theprintertoprinttheletteryoujustwrote,orsimplydirectingthearithmetic/logicunittoaddtwonumbers.本句可译为：例如，这可能涉及命令从磁盘存储器取数据，“告知”打印机打印你刚写好的信，或简单地命令算术/逻辑单元做两数相加的运算。

[3]Thestoredcontentsinmemoryarevolatileandcanvanishveryquickly,asduringapowerfailure.

本句可译为：当电源出故障时，RAM存储器中的内容是易失的，并且会消失得非常迅速。

[4]ThebanksofRAMchips(agroupofchips,usuallynine,arrangedinarow)…

在这里，括号里的内容就是对“ThebanksofRAMchips”的解释。“bank”译为“存储体”，是一组芯片，一般九个一组，成一行排列。

本句可译为：RAM芯片的存储体(存储体是一组芯片，通常九个一组排成一排)……

EXERCISES

Ⅰ.

TranslatethefollowingphrasesintoEnglish.

控制单元 电信号 主存 语言处理器

硬盘 电磁信号 显示器 复杂的软件程序

串行口 电路板 图像显示屏幕 可编程只读存储器

Ⅱ.

TranslatethefollowingphrasesintoChinese.

(1)

centralprocessingunit

(2)

physicalsize

(3)

arithmetic/logicunit

(4)

highlevelinstructions

(5)

binaryform

(6)

diskstoragedevice

(7)

imageclarity

(8)

microprocessorchip

(9)

highcapacityharddiskdrive

(10)

batterypoweredclock

(11)

memoryexpansioncard

(12)

readonlymemory

(13)

erasableprogrammablereadonlymemory

Ⅲ.

TranslatethefollowingparagraphsintoChinese.

(1)

Thecontrolunitisresponsiblefordirectingandcoordinatingmostofthecomputersystemsactivities.Itdeterminesthemovementofe1ectronicsignalsbetweenmainmemoryandthearithmetic/logicunit,aswellasthecontrolsignalsbetweentheCPUandinput/outputdevices.

(2)

Justasacarisuselesswithoutgas,acomputerisnotmuchgoodwithoutsoftwareinstructions.Whenweusesoftware,weareworkingwithhighlevelinstructionsthataretobecarriedoutbythecontrolunit.Theseinstructionsareconvertedbyalanguageprocessorintoalowlevelformofinstructionsthatthecomputercanworkwithmachinelanguage,theonlylanguagethattheCPUcanunderstand.Inmachinelanguage,dataandinstructionsarerepresentedinbinaryform(0sand1s).

(3)

WithouttheALU,computerswouldnotbeabletodomostofthetasksthatwefinduseful.TheALUperformsallthearithmeticandlogicalfunctionsthatis,itadds,subtracts,multiplies,divides,anddoescomparisons.Thesecomparisons,whicharebasically“lessthan”,“greaterthan”,and“equalto”,canbecombinedintoseveralcommonexpressions,suchas“greaterthanorequalto”.Theobjectiveofmostinstructionsthatusecomparisonsistodeterminewhichinstructionshouldbeexecutednext.

(4)

Thepurposeofinputhardwareistocollectdataandconvertitintoaformsuitableforcomputerprocessing.Themostcommoninputdeviceisakeyboard.Itlooksverymuchlikeatypewriterkeyboard.Itskeysarearrangedinthetypicaltypewriterlayout.Therearealsoanumberofadditionalkeys.Theycanbeusedtoenterspecialcomputerrelatedcodes.Althoughitisn’ttheonlytypeofinputdeviceavailable,thecomputerkeyboardistheonethatismostgenerallyusedbythebusinesscommunity.

(5)

OneofthemostimportantfactstoknowaboutRAMisthatthepartofitscontentisheldonlytemporarily.Inotherwords,itisstoredonlyaslongasthemicrocomputeristurnedon.Whenyouturnthemachineoff,thecontentsimmediatelyvanish.Thestoredcontentsinmemoryarevolatileandcanvanishveryquickly,asduringapowerfailure.Itisthereforeagoodpracticetorepeatedlysaveyourworkinprocesstosecondarystoragemediumsuchasfloppydiskorharddisk.

参考译文

第十七单元计算机硬件基础

1．中央处理器

中央处理器(CPU)就如同计算机系统的心脏，它的配置决定了计算机运行速度的快慢。中央处理器是计算机部件中最复杂的，基于提供的指令直接负责大多数计算机系统活动。随着计算机的更新换代，中央处理器变得越来越小，速度和性能增长迅猛。当然，这些变化也产生了足够适合在桌面和膝上用的微型计算机。中央处理器包含控制单元和算术/逻辑单元(ALU)两部分。

控制单元负责指挥和调度大部分计算机系统活动。它决定了主存和算术/逻辑单元间的电子信号流动和中央处理器与输入/输出设备间的控制信号流动。

正如没有汽油无法使用汽车一样，计算机没有软件指令也是不行的。当我们使用软件时，我们使用的是被控制单元执行的高级指令。这些指令被语言处理机转换为计算机能懂的机器语言——低级指令格式。在机器语言中，用二进制数(0和1)表示数据和指令。一旦指令被转换为这种格式，它们就可以从主存中取回并通过控制单元进行译码。针对每条特定的指令，控制单元向计算机系统其他部件发出必要的控制信号，以满足处理需求。例如，这可能涉及命令从磁盘存储器取数据，“告知”打印机打印你刚写好的信，或简单地命令算术/逻辑单元做两数相加的运算。

如果没有算术/逻辑单元，计算机就不可能执行许多我们认为有效的任务。算术/逻辑单元能执行所有的数学和逻辑功能，即加、减、乘、除和比较。这类比较是基础比较，如“小于”、“大于”和“等于”，可以组成联合表达式，如“大于或等于”。大部分比较指令的作用是确定下面该执行哪条指令。

算术/逻辑单元控制计算速度，因此要从计算机用户接收大量信号。早期微机的速度一般用毫秒(千分之一秒)计量。新一代的微机速度则用纳秒(十亿分之一秒)计量。若把纳秒比作一分钟，则一分钟就等于1900年！

2．计算机硬件

计算机硬件可分为四类：输入硬件、存储硬件、处理硬件和输出硬件。

1)输入硬件

输入硬件用于收集数据并将数据转换为适合计算机处理的格式。最常见的输入设备就是键盘。它看起来非常像打字机键盘，与典型的打字机键位布局一致。还有一组数字附加键，可用于输入特殊计算机相关代码。虽然键盘并不是可获得的唯一输入设备，但是计算机键盘是工商业界最常使用的输入设备。

2)存储硬件

存储硬件按照一定的格式相对永久地存储计算机指令和数据，即关机后数据不会丢失，并能在需要处理时方便地找回。存储硬件以电磁信号或激光蚀刻点的方式存储数据，通常存储在盘片或磁带上，而不是纸上。

3)处理硬件

处理硬件用于检索、翻译和引导执行计算机提供的软件指令。处理硬件最常用的部件为中央处理器和主存储器。

中央处理器如同计算机的大脑，它负责读和翻译软件指令，并处理调度活动。中央处理器的设计要考虑处理能力和计算机的速度，当然还包括它能有效使用的主存储器容量。如果你的计算机配备了一个设计良好的中央处理器，你就能在很短的时间内完成高复杂度的任务。

可以将主存储器(也称为内存、基本存储或存储器)想象成一个电子桌面。你面前的桌面面积越大，你在桌面上放的东西就越多。同样的，如果你的计算机存储器很大，你就能在里面放置更多的简单软件指令或高级软件；一个拥有大存储器的计算机能胜任处理数千条指令，这些指令包含在更高级的软件程序中。大容量存储器还允许在一个操作周期操作大量数据和信息。

4)输出硬件

输出硬件的作用是让用户按照自己的方式查看计算机系统生成的信息。信息以硬拷贝或软拷贝方式输出。硬拷贝输出可以拿在手上看，如上面打印有文本(文字或数字)或图的纸。软拷贝显示在监视器(一个像电视一样的屏幕)上，可以在上面显示文本或图形。

3．监视器和系统单元

1)监视器

术语“监视器”常指屏幕、视频显示屏和阴极射线管(CRT)。这种设备提供了人与微机的主要的视觉对话方式。当你用键盘输入命令或数据时，你可以在监视器上看到刚输入的结果。彩色监视器常指RGB(RGB代表红、绿、蓝)监视器，它能以多种颜色显示文本和图形。监视器的大多数性能(包括图像清晰度和图像显示能力)取决于视频显示电路板的高级程度，该电路板一般包含在系统单元中。在任何情况下，用户需要合理地将软件与监视器的图像显示性能相匹配。

2)系统单元

计算机系统主机箱称为系统单元，一般包含有供电电源、系统板和存储设备(有些存储设备磁盘驱动经常是外置的)。这些要素定义如下：

(1)供电电源给所有系统单元内的部件供电。有些微机内的电源还负责给监视器供电。

(2)系统板常称为主板，是微机系统的主电路板，通常包含：①微处理器芯片；②主存储器芯片；③所有相关支持电路；④可插入附件的扩展插槽。

(3)存储设备通常是一个或多个软驱和大容量硬盘。软盘或磁盘是一种表面覆盖着一层纸或塑料的很薄的塑料盘片，能把数据用磁性的方法编码在盘片的表面。硬盘是一种硬磁盘，可存储的数据比软盘多很多。(并且硬盘驱动器访问数据的速度也比软盘驱动器快。)硬盘比软盘价格更高。大多数硬盘都是永久地安装在系统单元中，而软盘由于要便于携带，故常常用于在计算机间拷贝数据。

(4)附件：系统板上的扩展插槽允许用户给计算机系统添加新的部件。常添加的部件有：含有主存储器芯片的存储卡，可为系统提供附加主存；②内部调制解调器，可使计算机通过电话线或类似的电缆完成数据通信；③电池供电时钟和日历部件；④附加的打印机接口，可使用户与多种类型外设通信；⑤显卡。

4．RAM和ROM

众所周知的存储器芯片有两类，一类称为RAM，另一类称为ROM。

1)

RAM

RAM(随机存取存储器)芯片保存CPU正在处理的程序和数据，即它是一种临时或易失性存储器。

RAM的主要功能是存储：①要处理的数据；②用于处理数据的指令，即程序；③信息，即等待被输出或发送至二级存储器(如软驱中的软盘)处理后的数据。需注意的是，RAM的最大特点就是它只临时性地存储数据或程序。换句话说，它只在微机开机状态进行存储。一旦关机，RAM中所有的内容就立刻消失了。当电源出故障时，RAM存储器中存储的内容是易失的，并且会消失得非常迅速。因此，要养成即时将你进行的工作存到二级存储介质(如软盘或硬盘)中的习惯。

对于存储器，需注意的第二个重要因素是它的容量。RAM芯片的存储体(存储体是一组芯片，通常九个一组排成一排)有时位于存储器扩充插件卡上，适合于安装在主机机箱内并且有时位于主电路板上。RAM可存储数据的容量用字节表示。现在可购买的大部分个人计算机都配有1

GB左右的RAM，并且允许扩展。扩展RAM和扩展存储器有两类方法，选择哪类方法取决于计算机中微处理器的复杂程度。

2)

ROM

当你打开电源，计算机如何知道要做什么呢？它如何知道要去检查硬件部件(如键盘或监视器)是否连接正常呢？这些操作都是依靠执行指令来完成的，这些对计算机操作起到关键作用的指令被永久存储在只读存储器(ROM)芯片中，生产商将这种芯片安装在计算机内部。ROM中存储的指令可被永久读取，是非易失的。当计算机断电后，存储在ROM中的指令不会丢失。某些类型的ROM芯片给用户提供更多的灵活性。可编程只读存储器(PROM)芯片允许用户加入自己的数据和程序。可擦除可编程只读存储器(EPROM)芯片可用专门的紫外线设备改写；当然，在改写EPROM内的数据和程序时，必须将它们从计算机内取出来。电可擦除可编程只读存储器(EEPROM)芯片不用取出计算机就可以改写。

EXTENSIVETEXT

TheFutureofComputing

Siliconmicroprocessorshavebeentheheartofthecomputingworldformorethan40years.Inthattime,microprocessormanufacturershavecrammedmoreandmoreelectronicdevicesontomicroprocessors.InaccordancewithMoore’sLaw,thenumberofelectronicdevicesputonamicroprocessorhasdoubledevery18months.Moore’sLawisnamedafterIntelfounderGordonMoore,whopredictedin1965thatmicroprocessorswoulddoubleincomplexityeverytwoyears.ManyhavepredictedthatMoore’sLawwillsoonreachitsendbecauseofthephysicallimitationsofsiliconmicroprocessors.

Thecurrentprocessusedtopackmoreandmoretransistorsontoachipiscalleddeep-ultravioletlithography(DUVL),whichisaphotography-liketechniquethatfocuseslightthroughlensestocarvecircuitpatternsonsiliconwafers.DUVLwillbegintoreachitslimitaround2005.Atthattime,chipmakerswillhavetolooktoothertechnologiestocrammoretransistorsontosilicontocreatemorepowerfulchips.Manyarealreadylookingatextreme-ultravioletlithography(EUVL)asawaytoextendthelifeofsiliconatleastuntiltheendofthedecade.EUVLusesmirrorsinsteadoflensestofocusthelight,whichallowslightwithshorterwavelengthstoaccuratelyfocusonthesiliconwafer.

BeyondEUVL,researchershavebeenlookingatalternativestothetraditionalmicroprocessordesign.TwoofthemoreinterestingemergingtechnologiesareDNAcomputersandquantumcomputers.

DNAcomputershavethepotentialtotakecomputingtonewlevels,pickingupwhereMoore’sLawleavesoff.ThereareseveraladvantagestousingDNAinsteadofsilicon.

Aslongastherearecellularorganisms,therewillbeasupplyofDNA.ThelargesupplyofDNAmakesitacheapresource.

Unliketraditionalmicroprocessors,whicharemadeusingtoxicmaterials,DNAbiochipscanbemadecleanly.

DNAcomputersaremanytimessmallerthantoday’scomputers.

DNA’skeyadvantageisthatitwillmakecomputerssmaller,whileatthesametimeincreasingstoragecapacity,thananycomputerthathascomebefore.OnepoundofDNAbasthecapacitytostoremoreinformationthanalltheelectronic