Maxtor 91024D4 Cylinder Zero, Data Separator, Data Synchronizer, Data Transfer Rate, Disk

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GLOSSARY

CYLINDER

Onseveraldisksurfacessharingacommonrotationalaxis,theaggregateoftracksata givenradialposition.Asetofdisktracksthataresimultaneouslyunderthesetofread/ writeheads.Thisthree-dimensionalstoragevolumecanbeaccessedafterasingleseek.

CYLINDER ZERO

Theoutermostcylinderinadrivethatcanbeusedfordatastorage.

D

DATA

Anorderedcollectionofinformation.Inaspecificcase,itistheinformationprocessed byacomputer.

DATA SEPARATOR

Anelectroniccircuitwhichdecodesplaybackdataandproducesseparateclockanddata bits.Sometimesincorrectlyusedtodenotedatasynchronizer.

DATA SYNCHRONIZER

Anelectroniccircuitproducingaclocksignalthatissynchronouswiththeincoming datastream.Thisclocksignalisthenusedtodecodetherecordingcodebeingusedinto userdata.

DATA TRANSFER RATE

Inadiskortapedrive,therateatwhichdataistransferredtoorfromthestorage media.Itisusuallygiveninthousandsofbitspersecond(Kbit/second)ormillionsof bitspersecond(Mbit/second).

DEDICATED LANDING ZONE

Adesignatedradialzoneonthediskwherecontactstartingandstoppingoccurby design.

DEDICATED SERVO

Aservoschemeinwhichaprerecordedpatternonanotherwiseunuseddisksurface providespositioninformationtotheservocircuitrybymeansofaheadreadingthat surface.

DEFECT

Amagneticimperfectioninarecordingsurface.

DEFECT MANAGEMENT

Ageneralmethodologyofavoidingdataerrorsonarecordingsurfacebyavoidingthe useofknownbadareasofmedia.Usuallydefectivesectorsortracksareretiredanddata arewritteninalternatelocations.Severalalgorithmsarepossiblesuchas“sector slipping,”or“sparesectorpertrack.”

DEFECT MAP

Alistofdefectsthatfallwithinapass/failcriteriaofauser.Thislistisusuallyusedbyan operatingsystemoradiskdrivecontrollerfordefectmanagement.

DEFECT SKIPPING

Adefectmanagementschemeforavoidingsurfacedefects.Ithasdatawrittenbeforeand afterthedefect,insteadofusingalternatetracksorsectorstoavoiduseofthedefective area.

DENSITY

Generally,recordingdensity.Seeareal,bit,andstoragedensity.

DC ERASE

ThemethodoferasingatrackusingaDCwrite/erasecurrentthrougheitheraRead/ WriteorErasehead.

DIGITAL

Anysystemthatprocessesdigitalbinarysignals(havingonlyvaluesofa1or0;usually inbitsandbytes)ratherthananalogsignals(signalsthatcanhavemanyvalues)

DIGITAL MAGNETIC RECORDING

Seemagneticrecording.

DIRECT ACCESS

Accessdirectlytomemorylocation.(Seerandomaccess).

DIRECT MEMORY ACCESS

Ameanofdatatransferbetweenthedeviceandhostmemorywithoutprocessor intervention.

DIRECTORY

Alistingoffilesmaintainedbythediskoperationsystem(DOS)oradatabase managementsystemtoenableausertoquicklyaccessdatafiles.

DISK

Aflat,circularpieceofmetal(usuallyaluminum)orplastic(usuallymylar)witha magneticcoatinguponwhichinformationcanberecorded.(See,forexample,floppy diskorWinchesterdisk)

DISK DRIVE OR DISK MEMORY DEVICE

Thetotalelectromechanicalstoragedevicecontainingdisksandread/writeheads,head positioningmechanism,drivemotor,andelectronics.

DISK PACK

Anumberofmetaldiskspackagedinacanisterforremovalfromthediskdrive (predecessorofWinchestertechnology).

DISK OPERATING SYSTEM (DOS) Themastercomputersystemprogramthatschedulestasks,allocatesthecomputersystem resources,controlsaccessestomassstoragedevices,managesfiles,andsoforth.Typical diskoperatingsystemsincludeCP/M,MS-DOS,andUNIX.

DISK STORAGE

Auxiliarymemorysystemcontainingdiskdrives.

DISK TRANSFER RATE

Theratethatdigitaldataistransferredfromonepointtoanother.Expressedineither bits/secondorbytes/second.

DOUBLE FREQUENCY ENCODING

AnothernameforFMencoding.Thisisbecauseallpossibledatacombinationswill resultinonlytwopossibletemporaldisplacementsofadjacentdatabits,specifically “1F”and2F.”

E

EARLY WINDOW

Adatawindowthathasbeenintentionallyshiftedintimeinanearlydirection.

EMBEDDED SERVO

Aservotechniqueusedfortrackfollowing.Positioninformationisprerecorded betweendataareasinatracksothatadatahead,andproperadditionalcircuitry,can determinethedataheadlocationwithrespecttothecenterpositionofthetrack(or cylinder)inquestion.

ERASE

Aprocessbywhichasignalrecordedonamediumisremovedandthemediummade readyforrerecording.

ERROR CORRECTION CODE (ECC)

Amathematicalalgorithmthatcandetectandcorrecterrorsinadatafield.Thisis accomplishedwiththeaidofCheckBitsaddedtotherawdata.

ERROR FREE

Arecordingsurfacethathasnodefects.

ERROR RATE

Thenumberoferrors(typemustbespecified)thatoccurinaspecifiednumberofbits read.

ERROR RECOVERY PROCEDURE

Theprocessthatoccursinresponsetoadataerror.InadrivewithoutECC,this wouldincludere-calibrationandre-seekingtothespecifiedtrackandrereadingthe specifieddata.

EXTRA PULSE

Termusedinsurfacecertification.Itiswhenafluxfielddiscontinuityremainsafterthe recordingsurfaceiserased,therebyproducinganelectricaloutputofareadhead passingovertheareawiththediscontinuity.Anextrapulseoccurswhentheelectrical outputislargerthanaspecifiedthreshold.

F

FEEDBACK

Inaclosed-loopsystem,theoutputsignal(fromtheservohead)isusedtomodifythe inputsignal(tothepositioner).

FETCH

Areadoperationanditsrelateddatatransferoperations.

GL – 2

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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 InterfaceInterface Commands Service and SupportGlossary Figures Manual Organization IntroductionMaxtor Corporation AbbreviationsKey Words Signal ConventionsConventions NumberingDiamondMax Plus 5120 Key Features Product DescriptionProduct Features Functional / InterfaceDefect Management Zone DMZ On-the-Fly Hardware Error Correction Code ECCLogical Block Addressing Software ECC CorrectionBuffer Segmentation Read-Ahead ModeCache Management Automatic Write Reallocation AWRMajor HDA Components Cylinder Limitation Subsystem ConfigurationJumper Location/Configuration Dual Drive SupportPerformance Specifications Product SpecificationsDrive Configuration Models and CapacitiesPhysical Dimensions Parameter Standard MetricEPA Energy Star Compliance Power RequirementsPower Mode Definitions Environmental LimitsReliability Specifications Shock and VibrationSafety Regulatory Compliance Radiated Electromagnetic Field Emissions EMC ComplianceCanadian Emissions Statement Pre-formatted Drive Handling and InstallationHard Drive Handling Precautions Important NoticeUnpacking and Inspection Multi-pack Shipping ContainerPhysical Installation Recommended Mounting ConfigurationRepacking Before You Begin General Requirements Mounting Drive in System Attaching Interface Power Cables System Setup Hard Drive Preparation System Hangs During Boot AT Interface Description Interface ConnectorSignal 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 Host Software Interface Error RegisterFeatures Register Task File RegistersCylinder Number Registers Sector Count RegisterSector Number Register Device/Head RegisterCommand Register Command Name Command Code Parameters Used SDH SummaryDevice Control Register Control Diagnostic RegistersAlternate Status Register Digital Input RegisterReset and Interrupt Handling Reset HandlingInterrupt Handling Interface Commands Set Feature CommandsRead Commands Read SectorsRead Verify Sectors Read DMA Read MultipleWrite Sectors Write CommandsSet Multiple Mode 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 Seek, Format and Diagnostic Commands Execute Drive DiagnosticFormat Track A.R.T. Command Set Execute S.M.A.R.TNo Quibble Service Service and SupportService Policy SupportMaxFax Service Customer ServiceInternet Glossary Error Correction Code ECC Direct AccessDirect Memory Access Error FreeFile Allocation Table FAT Hard ErrorHead Disk Assembly HDA Flux Changes PER InchLogical Block Addressing Phase Locked Loop PLLLogical Address Logical SectorRecoverable Error Random Access Memory RAMRead Gate Signal Sector Pulse SignalWrite Gate Signal UN-CORRECTABLE ErrorUnrecoverable Error THIN-FILM Media
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