MODULE10ComputersPart2:TeachingResources第二部分教学资源Section1:BackgroundReadings1.FormingaWH-questionWH-questions(usingwordssuchas"what","when","where"etc.)arealsocreatedbyputtingtheauxiliarydobeforethesubject.Then,youaddtheWH-wordatthebeginning.Herearesomeexamples:StatementYes/noquestionWH-questionIsingDoIsing?WhatdoIsing?Youspeak.Doyouspeak?Whydoyouspeak?HelivesDoeshelive?Wheredoeshelive?2.Whatisacomputer?Acomputerisadeviceormachineforprocessinginformationfromdataaccordingtoaprogram—acompiledlistofinstructions.Theinformationtobeprocessedmayrepresentnumbers,text,pictures,orsound,amongstmanyothertypes.Computersareextremelyversatile.Infact,theyareuniversalinformationprocessingmachines.AccordingtotheChurch-Turingthesis,acomputerwithacertainminimumthresholdcapability(intechnicalterms,onewaytodescribethisisthatthemachinemusthavetheabilitytoemulateauniversalTuringmachine)isinprinciplecapableofperformingthetasksofanyothercomputer,fromthoseofapersonaldigitalassistanttoasupercomputer.Therefore,thesamecomputerdesignshavebeenadaptedfortasksfromprocessingcompanypayrollstocontrollingindustrialrobots.Modernelectroniccomputersalsohaveenormousspeedandcapacityforinformationprocessingcomparedtoearlierdesigns,andtheyhavebecomeexponentiallymorepowerfulovertheyears.ThisprocesswasdubbedMoore'sLaw.Computersarepresentinavarietyofphysicalpackages.Theoriginalcomputerswerethesizeofalargeroom,andsuchenormouscomputingfacilitiesstillexistforspecialisedscientificcomputation-supercomputers-andforthetransactionprocessingrequirementsoflargecompanies,generallycalledmainframes.Smallercomputersforindividualuse,calledpersonalcomputers,andtheirportableequivalentthenotebookcomputer,areubiquitousinformationprocessingandcommunicationtoolsandareperhapswhatmostnon-expertsthinkofas"acomputer".However,themostcommonformofcomputerinusetodayistheembeddedcomputer,a(usually)smallcomputerusedtocontrolanotherdevice.Machinesfromfighterplanestodigitalcamerasarecontrolledbyembeddedcomputers.3.TheInternetTheInternet,orsimplytheNet,isthepubliclyaccessibleworldwidesystemofinterconnectedcomputernetworksthattransmitdatabypacketswitchingusingastandardizedInternetProtocol(IP)andmanyotherprotocols.Itismadeupofthousandsofsmallercommercial,academic,domesticandgovernmentnetworks.Itcarriesvariousinformationandservices,suchaselectronicmail,onlinechat,andtheinterlinkedwebpagesandotherdocumentsoftheWorldWideWeb.
