Maxtor 91280D5 Logical Address, Logical Block Addressing, Logical Sector, LOW Frequency, Memory

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GLOSSARY

LOGICAL ADDRESS

Astoragelocationaddressthatmaynotrelatedirectlytoaphysicallocation.Usually usedtorequestinformationfromacontroller,whichperformsalogicaltophysical addressconversion,andinturn,retrievesthedatafromaphysicallocationinthemass storageperipheral.

LOGICAL BLOCK ADDRESSING

Definestheaddressingofthedevicebythelinearmappingofsectors.

LOGICAL SECTOR

ThelowestunitofspacethatDOScanaccessthroughadevicedriver;oneormore physicalsectors.

LOW FREQUENCY

Thelowestrecordingfrequencyusedinaparticularmagneticrecordingdevice.With FMorMFMchannelcodes,thisfrequencyisalsocalled“IF.”

M

MAIN MEMORY Random-accessmemory(RAM)usedbythecentralprocessingunit(CPU)forstoring programinstructionsanddatacurrentlybeingprocessedbythoseinstructions.(Seealso randomaccessmemory.)

MASS STORAGE

Auxiliarymemoryusedinconjunctionswithmainmemory;generallyhavingalarge, on-linestoragecapacity.

MEGABYTE (MB)

Aunitofmeasureapproximatelyonemillionbytes(actually1,048,576bytes)or106.

MEMORY

Anydeviceorstoragesystemcapableofstoringandretrievinginformation.(Seealso storagedefinitions.)

MICROCOMPUTER

Acomputerwhosecentralprocessingunitisamicroprocessor.Itisusually,butnot necessarily,desktopsize.

MICROPROCESSOR

Acentralprocessingunit(CPU)manufacturedasachiporasmallnumberofchips.

MISSING PULSE

Atermusedinsurfacecertification.Itiswhenaprerecordedsignalisreducedin amplitudebyacertainspecifiedpercentage.

MODIFIED FREQUENCY MODULATION (MFM)

Amethodofencodingdigitaldatasignalsforrecordingonmagneticmedia.Alsocalled “threefrequencyrecording.”Recordingcodethatonlyusessynchronizingclockpulse ifdatabitsarenotpresent.Doublesthelinealbitdensitywithoutincreasingthelineal fluxreversaldensity,comparedtoFrequencyModulation.

MODIFIED MODIFIED FREQUENCY MODULATION (MMFM)

ArecordingcodesimilartoMFMthathasalongerrunlengthlimiteddistance.

MODULATION

1.Readbackvoltagefluctuationusuallyrelatedtotherotationalperiodofadisk.2.A recordingcode,suchasFM,MFM,orRLL,totranslatebetweenfluxreversalsandbits orbytes.

N

NON-RETURN TO ZERO

Aformofdataencodingthatisnotself-clocking,inotherwords,itneedstobe providedwithanexternalbitcellclocksignal.Generallyusedinhigher-performance diskdrives.

O

OFF-LINE processingorperipheraloperationsperformedwhiledisconnectedfromthesystem CPUviathesystembus.

ON-LINE processingorperipheraloperationsperformedwhiledisconnectedfromthesystem CPUviathesystembus.

OPEN LOOP SERVO

Aheadpositioningsystemthatdoesnotusepositionalinformationtoverifyandcorrect theradiallocationoftheheadrelativetothetrack.Thisisusuallyachievedbyuseofa steppermotorwhichhaspredeterminedstoppingpointthatcorrespondstotrack locations.

OPERATING SYSTEM

Asoftwareprogramthatorganizestheactionsofthepartsofthecomputerandits peripheraldevices.(Seediskoperatingsystem.)

OUTSIDE DIAMETER

Thelargestradiusrecordingtrackonadisk.

OVERWRITE

Atestthatmeasurestheresidual1Frecordedfrequencyonatrackafterbeing overwrittenbya2Fsignal.Variationsofthetestexist.

P

PARALLELISM

1.Theconditionoftwoplanesorlinesbeingparallel.Importantindiskdrivesbecause alackofitinmechanicalassembliescanresultinpositioninginaccuracy.More precisely:planes-coplanar;lines-colinear.2.Isthelocalvariationindiskthickness measuredindependentlyofthicknessitself.3.Theabilityofamultiprocessorcomputer toallocatemorethanoneprocessor(CPU)toacomputingproblem,whereeachCPU worksonaseparateproblemorseparatesegmentofthatproblem.Alsoreferredtoas parallelprocessing.

PARITY

Asimplemethodofdataerrordetectionsthatalwaysmakesnumberseitheroddor even,usinganextrabitinwhichthetotalnumberofbinary1s(or0s)inabyteis alwaysoddoralwayseven;thus,inanoddparityscheme,everybytehaseightbitsof dataandoneparitybit.Ifusingoddparityandthenumberof1bitscomprisingthe byteofdataisnotodd,theninthorparitybitissetto1tocreatetheoddparity.Inthis way,abyteofdatacanbecheckedforaccuratetransmissionbysimplycountingthe bitsforanoddparityindication.Ifthecountisevereven,anerrorisindicated.

PARTITION

Alogicalsectionofadiskdrive,eachofwhichbecomesalogicaldevicewithadrive letter.

PEAK SHIFT

Theshiftingintimeofthezero-slopeportionofareadbackvoltagefromthevalues containedinthewritecurrentwaveform.Sometimesincorrectlyusedtodescribebit jitter.

PERIPHERAL EQUIPMENT

Auxiliarymemory,displays,printers,andotherequipmentusuallyattachedtoa computersystem’sCPUbycontrollersandcables.(Theyareoftenpackagedtogetherin adesktopcomputer.)

PHASE LOCKED LOOP (PLL)

Acircuitwhoseoutputlocksontoandtracksthefrequencyofaninputsignal. Sometimesincorrectlycalledadataseparator.

PHASE MARGIN Measureindegreesoftheamountofdifferencebetweenexcursionsfromthewindow centerwherefluxreversalscanoccurandtheedgeofthedatawindow.Similarto windowmargin.

PHYSICAL SECTOR

Thesmallestgroupingofdataontheharddisk;always512bytes.

PIO

ProgrammableInputOutput.Ameansofaccessingdeviceregisters.Alsodescribesone formofdatatransfers.PIOdatatransfersareperformedbythehostprocessorusing PIOregisteraccessestothedataregister.

PLATED THIN FILM MEDIA

Magneticdiskmemorymediahavingitssurfaceplatedwithathincoatingofametallic alloyinsteadofbeingcoatedwithoxide.

PROCESSING

Theprocessofthecomputerhandling,manipulatingandmodifyingdatasuchas arithmeticcalculation,filelookupandupdating,andwordpressing.

PULSE CROWDING

Modificationofplaybackamplitudeduetosuper-positioningofadjacentfluxreversal fieldsbeingsensedbytheread/writegap.

PULSE DETECT

Adigitalpulsetraininwhicheachleadingedgeoreachedgecorrespondstoa magnetictransitionreadfromthedisk.Iftransitionqualificationcircuitryexistsinthe drive,thissignalistheoutputofsame.Alsoknownastransitiondetect.

GL – 4

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Contents HA RD Drive Produc T MA Nual DiamondMax Plus Revisions Manual No Before You Begin U T I O NContents Product Specifications Handling and InstallationAT Interface Description Host Software InterfaceGlossary Interface CommandsService and Support Figures Introduction Maxtor CorporationManual Organization AbbreviationsSignal Conventions ConventionsKey Words NumberingDiamondMax Plus 5120 Key Features Product DescriptionProduct Features Functional / InterfaceOn-the-Fly Hardware Error Correction Code ECC Logical Block AddressingDefect Management Zone DMZ Software ECC CorrectionRead-Ahead Mode Cache ManagementBuffer Segmentation Automatic Write Reallocation AWRMajor HDA Components Subsystem Configuration Jumper Location/ConfigurationCylinder Limitation Dual Drive SupportProduct Specifications Drive ConfigurationPerformance Specifications Models and CapacitiesPhysical Dimensions Parameter Standard MetricPower Requirements Power Mode DefinitionsEPA Energy Star Compliance Environmental LimitsReliability Specifications Shock and VibrationCanadian Emissions Statement Safety Regulatory ComplianceRadiated Electromagnetic Field Emissions EMC Compliance Handling and Installation Hard Drive Handling PrecautionsPre-formatted Drive Important NoticeUnpacking and Inspection Multi-pack Shipping ContainerRepacking Physical InstallationRecommended Mounting Configuration Before You Begin General Requirements Mounting Drive in System Attaching Interface Power Cables System Setup Hard Drive Preparation System Hangs During Boot Interface Connector SignalAT Interface Description Pin Description SummaryPIN Name Signal Name Signal Description Pin Description TableTiming Parameters Mode PIO TimingDMA Timing Ultra DMA Timing Timing Parameters all times in nanosecondsSustained Ultra DMA Data In Burst Device Terminating an Ultra DMA Data In Burst Initiating an Ultra DMA Data Out Burst Device Pausing an Ultra DMA Data Out Burst Device Terminating an Ultra DMA Data Out Burst Error Register Features RegisterHost Software Interface Task File RegistersSector Count Register Sector Number RegisterCylinder Number Registers Device/Head RegisterCommand Register Command Name Command Code Parameters Used SDH SummaryControl Diagnostic Registers Alternate Status RegisterDevice Control Register Digital Input RegisterInterrupt Handling Reset and Interrupt HandlingReset Handling Interface Commands Set Feature CommandsRead Verify Sectors Read CommandsRead Sectors Read DMA Read MultipleWrite Commands Set Multiple ModeWrite Sectors Write Verify SectorsWrite Multiple Write DMASet Feature Commands Set Features ModePower Mode Commands Sleep Mode Initialization Commands Identify Drive15-8 = PIO data transfer mode = Write Cache enabled Initialize Drive Parameters Format Track Seek, Format and Diagnostic CommandsExecute Drive Diagnostic A.R.T. Command Set Execute S.M.A.R.TService and Support Service PolicyNo Quibble Service SupportInternet MaxFax ServiceCustomer Service Glossary Direct Access Direct Memory AccessError Correction Code ECC Error FreeHard Error Head Disk Assembly HDAFile Allocation Table FAT Flux Changes PER InchPhase Locked Loop PLL Logical AddressLogical Block Addressing Logical SectorRandom Access Memory RAM Read Gate SignalRecoverable Error Sector Pulse SignalUN-CORRECTABLE Error Unrecoverable ErrorWrite Gate Signal THIN-FILM Media
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