Computer Science 230 Final Exam Questions and Answers Updated 2026

Computer Science 230
Final Exam Questions and
Answers Updated 2026
GivenBtheBpageBtableBbelow,BforBeachBPTEB0~7,BmatchBthemBtoBoneBofBtheBfollowing
Bstatus:B-BAnswerBUnallocatedB->BWhereBValidBisB0BandBhasBNull



AllocatedBandBUncachedB->BWhereBvalidBisB0BandBisBinBtheBdisk/BvirtualBmemory



AllocatedBandBCachedB->BWhereBvalidBisB1BandBisBinBtheBdram/BphysicalBmemory



True/False:BPageBtablesBalwaysBmapBvirtualBmemoryBaddressesBtoBphysicalBaddressesBi
nBtheBRAM.B-BAnswerBFalse



AddressBtranslationBinBaBvirtualBmemoryBsystemBreceivesBaB_________BwhichBisBconve
rtedBintoBaBcorrespondingB_________BbeforeBitBisBsentBoffBtoBmainBmemory.B-
BAnswerB1.BVirtualBaddressBconvertedBintoBcorrespondingB2.BphysicalBaddress



True/False:BTheBvirtualBpageBnumberB(VPN)BcorrespondsBtoBanBindexBinBtheBpageBtabl
e.B-BAnswerBTrue



WhatBdoesBaBPageBTableBEntryB(PTE)Bcontain?B-
BAnswerBBothBaBvalidBbitBandBanBaddressBfield



WhatBisBtheBdedicatedBpieceBofBhardwareBthatBimplementsBaddressBtranslationBforBvirt
ualBmemory?B-BAnswerBMemoryBmanagementBunitB(MMU)



True/False:BAB"pageBhit"BmeansBthatBtheBpageBbeingBlookedBupBisBstoredBinBvirtualBm
emory,BasBopposedBtoBphysicalBmemoryB-BAnswerBFalse

,AssumeBaBvirtualBaddressBspaceBwithBcardinalityBNB=B232BandBaBphysicalBaddressBspac
eBwithBcardinalityBMB=B288.BComputeBtheBminimumBnumberBofBbitsBnecessaryBtoBrep
resentBaBPPNB--BthatBis,BaBphysicalBpageBnumberB--
BgivenBaBpageBsizeBofBPB=B1BMiBB=B220Bbytes.B-BAnswerBM(88)-P(20)

68



True/False:BWhenBanBentryBinBaBpageBtableBhasBitsBvalidBbitBsetBtoB"invalid"B(0),BtheB
"address"BfieldBofBthatBentryBmayBreferBtoBanBaddressBonBdiskB-BAnswerBTrue



GivenBtheBpageBtableBbelow,BaBreceivedBvirtualBaddress,BwhichBmapsBtoBPTEBx.BAnswe
rBPageBFaultBifBtheBaddressBcausesBPageBFault.BOtherwise,BAnswerBNone.B-
BAnswerBPageBfaultBifBvalidBbitBisB0

NoneBifBvalidBbitBisB1



WhichBofBtheBfollowingBareBbenefitsBofBusingBvirtualBmemory?B-
BAnswerBItBtreatsBmainBmemoryBasBaBcacheBforBanBaddressBspaceBstoredBonBdisk



ItBprotectsBtheBaddressBspaceBofBeachBprocessBfromBcorruptionBbyBotherBprocesses



ItBusesBmainBmemoryBefficientlyBforBmultitaskingBoperatingBsystem



WhereBpagesBareBareBswappedBinBandBoutBcontinuouslyBdueBtoBaBprogramBusingBmor
eBdataBthanBcanBfitBinBmemoryB-BAnswerBThrashing



WaitingBuntilBaBmissBoccursBinBorderBtoBswapBaBpageB-BAnswerBDemandBPaging



FixedBsizeBblocksBofBbytesBinBvirtualBmemoryBsystemB-BAnswerBPage



MovingBdataBfromBdiskBtoBmainBmemoryB-BAnswerBPagingBin

,AnBorderedBsetBofBnonnegativeBintegersBinBmemoryB-BAnswerBAddressBspace



MovingBdataBfromBmainBmemoryBtoBdiskB-BAnswerBPagingBout



LetBNB=B16,BMB=B64,BandBPB=B4,BwhereBNBisBtheBnumberBofBvirtualBaddresses,BMBis
BtheBnumberBofBphysicalBaddressesBinBmainBmemory,BandBPBisBtheBpageBsizeBinBbytes
.BGivenBtheBtableBbelow,BwhatBisBtheBphysicalBaddressB(inBdecimalBorBbinary)BthatBcor
respondsBtoBvirtualBaddressB0x4?



PageBtable

ValidBbitBPPN

0B11001B

0B10101B

0B10001B

0B01101B-BAnswerB0x4BinBbinaryBisB000100



01BcorrespondsBtoBPageBnumberB(middleBtwoBbits)

00BisBtheBaddressB(rightBtwoBbits)



TrackB1BtoBbeBPPNB10101

ThenBappendBaddressB00BtoBPPNB1



ResultB->B1010100B(84)



intBmain()B{B

printf("A\n");

fork();B

printf("B\n");B

printf("C\n");B

, returnB0;

}



HowBmanyBuniqueBoutputsBcanByouBgetBfromBthisBcode?B-BAnswerB2BUniqueBoutputs

ForkBthenBrunBbutBBBneedsBtoBcomeBbeforeBC

BCBCBorBBBCC



pid1=fork();B

pid2=fork();B

pid3=fork();

ifB(pid2B==B0)B{B

printf("A\n");

}

ifB(pid3B==B0)B{B

printf("B\n");

}



AssumingBallBtheBforksBdoBnotBfail.BIfBweBknowBtheBnumberBofBABthatBisBprintedBout
BisBXBandBtheBnumberBofBBBthatBisBprintedBoutBisBY,Bwhat'sBtheBvalueBofBXB+BY?B-
BAnswerB8BThereBareB4BA'sBandB4BB'sBprinted



ForkB3Btimes:

WhereBsecondBforkBhappensBifBgoingBup,BthenBprintBanBA

WhereBthirdBforkBhappensBifBgoingBup,BthenBprintBaBB



intBmain()B{

pid_tBpid,Bmypid;B

pidB=Bfork();

ifB(pidB==B0)B{