Chapter-1-–-Computer-Systems-Overview-Q&A

OperatingSystemsChapter1–ComputerSystemsOverviewPage1of6Chapter1–ComputerSystemsOverviewTrue/FalseQuestions:1.T/F–Theoperatingsystemactsasaninterfacebetweenthecomputerhardwareandthehumanuser.ANS:T2.T/F–Oneoftheprocessor’smainfunctionsistoexchangedatawithmemory.ANS:T3.T/F–User-visibleregistersaretypicallyaccessibletosystemprogramsbutarenottypicallyavailabletoapplicationprograms.ANS:F(typicallyavailabletoallprograms)4.T/F–Dataregistersaregeneralpurposeinnature,butmayberestrictedtospecifictaskssuchasperformingfloating-pointoperations.ANS:T5.T/F–TheProgramStatusWordcontainsstatusinformationintheformofconditioncodes,whicharebitstypicallysetbytheprogrammerasaresultofprogramoperation.ANS:F(setbytheprocessorhardware)6.T/F–TheprocessingrequiredforasingleinstructiononatypicalcomputersystemiscalledtheExecuteCycle.ANS:F(calledtheInstructionCycle)7.T/F–AfetchedinstructionisnormallyloadedintotheInstructionRegister(IR).ANS:T8.T/F–Aninterruptisamechanismusedbysystemmodulestosignaltheprocessorthatnormalprocessingshouldbetemporarilysuspended.ANS:T9.T/F–Toaccommodateinterrupts,anextrafetchcycleisaddedtotheinstructioncycle.ANS:F(interruptcycleisadded)10.T/F–Theminimuminformationthatmustbesavedbeforetheprocessortransferscontroltotheinterrupthandlerroutineistheprogramstatusword(PSW)andthelocationofthecurrentinstruction.ANS:F(locationofthenextinstruction)11.T/F–Oneapproachtodealingwithmultipleinterruptsistodisableallinterruptswhileaninterruptisbeingprocessed.ANS:TOperatingSystemsChapter1–ComputerSystemsOverviewPage2of612.T/F–Multiprogrammingallowstheprocessortomakeuseofidletimecausedbylong-waitinterrupthandling.ANS:T13.T/F–Inatwo-levelmemoryhierarchy,theHitRatioisdefinedasthefractionofallmemoryaccessesfoundintheslowermemory.ANS:F(foundinthefastermemory)14.T/F–Cachememoryexploitstheprincipleoflocalitybyprovidingasmall,fastmemorybetweentheprocessorandmainmemory.ANS:T15.T/F–Incachememorydesign,blocksizereferstotheunitofdataexchangedbetweencacheandmainmemoryANS:T16.T/F–TheprimaryproblemwithprogrammedI/OisthattheprocessormustwaitfortheI/OmoduletobecomereadyandmustrepeatedlyinterrogatethestatusoftheI/Omodulewhilewaiting.ANS:TMultipleChoiceQuestions:1.Thegeneralroleofanoperatingsystemisto:a.Actasaninterfacebetweenvariouscomputersb.Provideasetofservicestosystemusersc.Managefilesforapplicationprogramsd.NoneoftheaboveANS:B2.Thefourmainstructuralelementsofacomputersystemare:a.Processor,Registers,I/OModules&MainMemoryb.Processor,Registers,MainMemory&SystemBusc.Processor,MainMemory,I/OModules&SystemBusd.NoneoftheaboveANS:C3.Thetwobasictypesofprocessorregistersare:a.User-visibleandControl/Statusregistersb.ControlandStatusregistersc.User-visibleanduser-invisibleregistersd.NoneoftheaboveANS:A4.Addressregistersmaycontain:a.MemoryaddressesofdataOperatingSystemsChapter1–ComputerSystemsOverviewPage3of6b.Memoryaddressesofinstructionsc.Partialmemoryaddressesd.AlloftheaboveANS:D5.AControl/Statusregisterthatcontainstheaddressofthenextinstructiontobefetchediscalledthe:a.InstructionRegister(IR)b.ProgramCounter(PC)c.ProgramStatusWord(PSW)d.AlloftheaboveANS:B6.Thetwobasicstepsusedbytheprocessorininstructionprocessingare:a.FetchandInstructioncyclesb.InstructionandExecutecyclesc.FetchandExecutecyclesd.NoneoftheaboveANS:C7.Afetchedinstructionisnormallyloadedintothe:a.InstructionRegister(IR)b.ProgramCounter(PC)c.Accumulator(AC)d.NoneoftheaboveANS:A8.Acommonclassofinterruptsis:a.Programb.Timerc.I/Od.AlloftheaboveANS:D9.Whenanexternaldevicebecomesreadytobeservicedbytheprocessor,thedevicesendsthistypeofsignaltotheprocessor:a.Interruptsignalb.Haltsignalc.Handlersignald.NoneoftheaboveANS:A10.Informationthatmustbesavedpriortotheprocessortransferringcontroltotheinterrupthandlerroutineincludes:a.ProcessorStatusWord(PSW)b.ProcessorStatusWord(PSW)&LocationofnextinstructionOperatingSystemsChapter1–ComputerSystemsOverviewPage4of6c.ProcessorStatusWord(PSW)&Contentsofprocessorregistersd.NoneoftheaboveANS:B11.Oneacceptedmethodofdealingwithmultipleinterruptsisto:a.Defineprioritiesfortheinterruptsb.Disableallinterruptsexceptthoseofhighestpriorityc.Servicetheminround-robinfashiond.NoneoftheaboveANS:A12.Inauniprocessorsystem,multiprogrammingincreasesprocessorefficiencyby:a.Increasingprocessorspeedb.Takingadvantageoftimewastedbylongwaitinterrupthandlingc.Eliminatingallidleprocessorcyclesd.AlloftheaboveANS:B13.Asoneproceedsdownthememoryhierarchy(i.e.,frominboardmemorytoofflinestorage),thefollowingcondition(s)apply:a.Increasingcostperbitb.Decreasingcapacityc.Increasingaccesstimed.AlloftheaboveANS:C14.Small,fastmemorylocatedbetweentheprocessorandmainmemoryiscalled:a.WORMmemoryb.Cachememoryc.CD-RWmemoryd.NoneoftheaboveANS:B15.Whenanewblockofdataiswrittenintocachememory,thefollowingdetermineswhichcachelocationtheblockwilloccupy:a.Blocksizeb.Cachesizec.Writepolicyd.NoneoftheaboveANS:D(mappingfunction)16.DirectMemoryAccess(DMA)operationsrequirethefollowinginformationfromtheprocessor:a.AddressofI/Odeviceb.Startingmemorylocationtoreadfromorwritetoc.NumberofwordstobereadorwrittenOperatingSy