Maxtor 91792D7 THIN-FILM Media, TRACK-FOLLOWING Servo, Tracks PER Inch TPI, Track Positioning

GLOSSARY

T

THIN-FILM HEAD Amagnetictransducermanufacturedbydepositionofmagneticandelectricalmaterials onabasematerialcontrastedwithpriorartmechanicalmethods.Read/writeheads whoseread/writeelementisdepositedusingintegratedcircuittechniquesratherthan beingmanuallywound.

THIN-FILM MEDIA

Seeplatedthinfilmmedia.

TRACK

Onesurfaceofacylinder.Apathwhichcontainsreproducibleinformationleftona magneticmediumbyrecordingmeansenergizedfromasinglechannel.

TRACK-FOLLOWING SERVO

Aclosed-looppositionercontrolsystemthatcontinuouslycorrectsthepositionofthe diskdrive’sheadsbyutilizingareferencetrackandafeedbackloopinthehead positioningsystem.(Seealsoclosedloop.)

TRACKS PER INCH (TPI)

Ameasurementofradialdensity.Tracksperinchofdiskradius.

TRACK POSITIONING

Themethod,bothmechanicalandelectrical,usedtopositiontheheadsoverthecorrect cylinderinadiskdrivesystem.

U

UN-CORRECTABLE ERROR

AnerrorthatisnotabletobeovercomewithErrorDetectionandCorrection.

UNFORMATTED CAPACITY

Storagecapacityofdiskdrivepriortoformatting;alsocalledthegrosscapacity.(See format.)Therawcapacityofadrivenottakingintoaccountthecapacitylossdueto storageoftheformatcontrolinformationonthedisksurfaces.

UNRECOVERABLE ERROR

AreaderrorfallingoutsidethecapabilityofanECCmechanismtocorrect,ornot abletobeovercomebyrereadingthedatainquestion,withorwithoutrepositioning thehead.

V

VOICE COIL MOTOR

Apositioningmotorthatusesthesameprincipleasavoicecoilinaloudspeaker.The motorhasnodetentpositions.Themechanicalmotionoutputofitcanbeeitherrotary orlinear.

W

WHITNEY HEAD

AsuccessortotheoriginalWinchesterread/writeheaddesign.Theprimarychange wastomaketheflexuresmallerandmorerigid.FirstusedinIBM3370/3380.

WHITNEY TECHNOLOGY

Amethodofconstructingaread/writeheadinarigiddiskdriveusingaWhitney head.InallotherdetailsitisthesameasWinchestertechnology.

WINCHESTER HEAD Theread/writeheadusedinWinchestertechnology,non-removablemediadisk drives.Maybeeitheramonolithicorcompositetype.Itisaerodynamicallydesigned toflywithinmicroinchesofthedisksurface.

WINCHESTER TECHNOLOGY

AmethodofconstructingarigiddiskdriveusingconceptsintroducedintheIBM model3340diskdrive.Theprimarychangesfrompriortechnologywastolowerthe massoftheslider,useofamonolithicslider,radicallychangingthedesignofthe flexureandhavingtheslidercometorestonalubricateddisksurfacewhendisk rotationceases.Inadditiontotheabove,atotallysealedchambercontainingtheread/ writeheadsanddiskswasusedtoprotectagainstcontamination.

WINDOW MARGIN

Theamountoftolerancearead/writesystemhasfortransitionjitterataspecifiederror ratelevel.

WORD

Anumberofbits,typicallyamultipleofeight,processedinparallel(inasingle operation).Standardwordlengthsare8,16,32and64bits(1,2,4,or8bytes).

WRITE

Therecordingoffluxreversalsonamagneticmedia.

WRITE PRE-COMPENSATION

Theintentionaltimeshiftingofwritedatatooffsettheeffectsofbitshiftinmagnetic recording.

WRITE GATE SIGNAL

Adigitalinputsignallevelwhichcausesthedrivecircuitrytorecord(write)data.

GL – 6