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<strong>Data</strong> <strong>Mark</strong> <strong>70</strong>/<strong>70</strong>F<strong>Data</strong> <strong>Module</strong>Aligned Oxide Particlesmx Surface Shield"Armor-tough" Recording SurfaceThe <strong>Data</strong> <strong>Mark</strong> <strong>70</strong>/<strong>70</strong>FThis successor memory device toconventional disc packs combinesdisc pack technology with disc driveengineering. The easy-to-handlemodule houses disc recordingsurfaces, recording heads, spindle,head carriage, base plate andelectronics circuitry, in a completelyself-contained unit. Greater dataintegrity is achieved because thehead that writes the data is the samehead that reads it into the computer.Mistracking and data checks, formerlycaused by minor misalignment ofheads, are now eliminated. <strong>Data</strong><strong>Mark</strong>'s factory-sealed module has aclosed-loop air system which resistspotential contamination which waspreviously a problem with conventional disc packs.Two <strong>Data</strong> <strong>Mark</strong> configurations areavailable: the <strong>Data</strong> <strong>Mark</strong> <strong>70</strong> with <strong>70</strong>million bytes of data storage; and the<strong>70</strong>F which provides low cost, fixedhead access to 502 thousand bytesof the <strong>70</strong> million byte capacity. Inaddition to being directly interchangeable with the IBM 3348 Model <strong>70</strong>/<strong>70</strong>Fand other IBM 3340 compatible datamodules, the <strong>Data</strong> <strong>Mark</strong> featuresmany product attributes not foundon all modules.substrate used to make a disc issubjected to nine separate qualitycontrol checks before finalacceptance for coating."Armor-Tough" CoatingSince the Company was founded in1961, Memorex has pioneered incoating computer tape, video tapeand disc packs. This experience hasled to a proprietary formulation andadvanced processing techniques forthe coating of <strong>Data</strong> <strong>Mark</strong> discs. Thisspecial "armor-tough" surface coatingextends disc durability and withstandshead loading stress.All processing of <strong>Data</strong> <strong>Mark</strong> discsoccurs in environmentally controlledclean rooms to eliminate potentialcontamination. The special formulation is applied to microinch accuracyusing sophisticated spin coatingtechniques. Coated surfaces are thencured and polished to exactingstandards.Advanced Substrate Preparation<strong>Data</strong> <strong>Mark</strong> disc substrates arelathe turned on air bearings to thestrictest of tolerances. They are thenpolished to a mirror-like smoothness.Years of experience in manufacturingdisc packs of high reliability hasresulted in exacting quality controlprocedures. For example, eachOxide particles on ordinary data discs,depicted on the left, are dispersed in alldirections. The oxide particles on the <strong>Data</strong><strong>Mark</strong> data disc, depicted on the right, arecircumterentially aligned around the disc.Oxide Particle AlignmentThe oxide particles encapsulatedwithin the extremely thin coating arecircumterentially aligned on the discby a proprietary process. Particlealignment provides the high outputand data resolution that is essentialfor reliable performance with high bitpacking densities. <strong>Data</strong> <strong>Mark</strong> discshave greater resolution and lessresidual noise than conventionallycoated discs. Additionally, particlealignment maximizes head-to-trackstability and assures cleaner erasuresand rewriting on all tracks.
Unique "100X" Surface ShieldBecause the recording heads are incontact with the discs during start/stop operations, Memorex developedThe disc on the left, protected by Memorex"100X" surface shield, has undergone theequivalent of ten years' normal operationwith no damage to the surface. The disc onthe right, without Memorex "100X," showsextensive damage after the equivalent ofonly one year of normal operation.a special surface shield to complement the "armor-tough" coating. Thissmooth and durable top shield wascalled "100X" because it protects thediscs and the data on it by extendingthe useful life of the data disc byone hundred times over any normaldiscs without the coating used insimilar applications. This combinationof "armor-tough" coating and "100X"surface shield provides greater dataintegrity and longer lasting operationalperformance.Improved Head TechnologyTwo recording heads per surfaceare sealed within the datamodule and are bothighter and closer flyingthan any previousheads. This providesgreater bit densitycapabilities, fasterdata access andimproved performance characteristics.Final Testing andAssembly<strong>Data</strong> <strong>Mark</strong> discs undergocomplete surface testing byusing special test heads in overlapping paths. Any potential irregularity or minute flaw is detected onspecially designed test equipment.The modules are then hand assembledand sealed in clean rooms thatadhere to the industry's most rigidstandards (Class 100). After finalassembly and exhaustive testing,the <strong>Data</strong> <strong>Mark</strong>s are subjected tofinal testing utilizing a systemdesigned to assure 100% performance at less than idealoperating conditions.Servo Track WritingRecording tracks on the <strong>Data</strong> <strong>Mark</strong>Disc are so narrow and close together that two of them could becontained on the edge of a dataprocessing card. To control the headalignment accuracy, a speciallywritten servo surface is used. Thisservo is pre-recorded at the factoryusing a special servo writer operatedunder strict environmental control.This assures true track-to-headalignment and precise cylinderlocation. After final formatting andtesting, the <strong>Data</strong> <strong>Mark</strong>s are speciallypackaged for storage and shipment.Experience Improves PerformanceThe production of <strong>Data</strong> <strong>Mark</strong> modulesspans a broad spectrum of scientificand engineering disciplines that havebeen a part of Memorex for manyyears. These areas in which Memorexhas proven expertise include discpack production, coating of discsand tape, manufacture of disc drivesand recording heads. This uniquebackground enables Memorex todesign and produce <strong>Data</strong> <strong>Mark</strong>s ofunsurpassed performance andreliability. Each unit is designed for alife of over five years with nomaintenance.
•Lock<strong>Data</strong> <strong>Mark</strong> <strong>70</strong>/<strong>70</strong>FSummary <strong>Data</strong>General SpecificationsThe <strong>Data</strong> <strong>Mark</strong> will meet or exceed thespecifications detailed in the IBMDocument ZA26-1629-1Physical Dimensions<strong>70</strong> <strong>70</strong>FHeight 8" 8"Width 16" 16"Length 18" 18"Shipping weight 23 lbs. 24 lbs.Disc InformationTotal disc per module4 eachTop protective disc1 eachDisc thickness - nominal0.075 inchesCoating thickness - nominalI.D. toO.D.35-50 microinchesSurface smoothnessLess than 1.0 microinchesSurface shield"100X" wear coatingRecording Surfaces<strong>Module</strong> <strong>Data</strong> Capacity<strong>Data</strong> surfaces <strong>Data</strong> <strong>Mark</strong> <strong>70</strong>6 each 69, 889, 536 bytes per moduleServo surface<strong>Data</strong> <strong>Mark</strong> <strong>70</strong>F1 each 69, 889, 536 bytes per module;Fixed head storage:502,080 of the above accessibleServo surface of Model <strong>70</strong>F only by fixed heads (cylinders 1-5)Bytes per trackRecording Heads 8368<strong>Data</strong> HeadTracks per cylinder12 each (2 per data surface) 12Servo headCylinders per module1 each 696Fixed heads (Model <strong>70</strong>F only)Bytes per cylinder10 each (three data elements per 100,416fixed head)Bit per inchServo TracksPre-recordedInitializationStandard home address and recordzero are written prior to shipmentMaintenance RequirementsNoneAccess TimeModelCylindersMaximumMinimumAverage<strong>70</strong> <strong>70</strong>F5636 nominalTracks per inch300Alternate cylinders2KmC. E. Cylinders •2Transfer Rate885,000 Bytes per secondRead Only0-695 1-5 0,6-69550 ms10 ms25 ms0 ms0 ms0 msLatency - Average 10.1 ms 10.1 ms 10.1 msLatency - Maximum 20.2 ms 20.2 ms 20.2 msRotational speed | 2964 rpm | 2964 rpm | 2964 rpmout on <strong>Data</strong> <strong>Mark</strong> handleEnvironmental Conditions60°Fto90°F20% to 80% relative humidity50 ms10 ms25msMemorex CorporationComputer Media Products1200 Memorex DriveSanta Clara, California 95052(408) 987-1000
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