Data Mark 70/70F Data Module - mrxhist.org

Data Mark 70/70FData ModuleAligned Oxide Particlesmx Surface Shield"Armor-tough" Recording SurfaceThe Data Mark 70/70FThis 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. DataMark's factory-sealed module has aclosed-loop air system which resistspotential contamination which waspreviously a problem with conventional disc packs.Two Data Mark configurations areavailable: the Data Mark 70 with 70million bytes of data storage; and the70F which provides low cost, fixedhead access to 502 thousand bytesof the 70 million byte capacity. Inaddition to being directly interchangeable with the IBM 3348 Model 70/70Fand other IBM 3340 compatible datamodules, the Data Mark 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 Data Mark discs. Thisspecial "armor-tough" surface coatingextends disc durability and withstandshead loading stress.All processing of Data Mark 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 PreparationData Mark 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 DataMark 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. Data Mark discshave greater resolution and lessresidual noise than conventionallycoated discs. Additionally, particlealignment maximizes head-to-trackstability and assures cleaner erasuresand rewriting on all tracks.