Seagate STT8000A manual Mechanics, Cartridge load mechanism, Capstan drive motor assembly, Chassis

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Chapter 7

Theory of operations

The following table shows clock frequencies used by the STT8000 drive

VCO Frequencies—All Derived from System Clock (42 MHz Crystal Oscillator)

Fundamental	28 MHz	28 MHz	28 MHz	24.89 MHz
Frequency

Channel	9.33 MHz	7.00 MHz	4.667 MHz	3.11 MHz
Frequency

Mechanics

The mechanical package for the STT8000 ATAPI minicartridge drive was designed to provide all the advantages of easy cartridge loading and unloading while maintaining the positioning accuracy necessary for high-density data recording. The orientation of the cartridge is the same as the majority of QIC minicartridge drives in the field.

Cartridge load mechanism

The cartridge is inserted in the drive by sliding it through the aperture in the bezel and into a tray mechanism. When fully inserted the back portion of the cartridge protrudes about 3/4-inch from the aperture. A switch is actuated at this point that causes a microprocessor to complete the loading operation.

When the tape is in motion, the amber LED on the front panel flashes. The LED is not lit when the tape is positioned at BOT.

Capstan drive motor assembly

In the STT8000 ATAPI minicartridge drive, the cartridge is driven by the capstan/belt motor assembly, which is on a linear slide. The cartridge is loaded against the cartridge drive roller which exerts a net radial dynamic force of 18 to 26 ounces. The motor is a brushless DC drive motor with integral capstan which is designed to provide maximum reliability.

The motor operates from the 12V nominal supply and moves the tape at speeds from 35 to 100 inches per second (IPS).

Chassis

The drive mechanism is mounted in a molded frame that provides the mounting holes for the industry standard 3.5-inch by one inch form factor. A 5.25-inch mounting kit is an available option. The bezel is a simple snap-on design that is available in several standard and custom colors. The round, front-panel LED is amber and indicates tape activity.

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STT8000A Product Manual

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Contents STT8000A Atapi Minicartridge Drive Product Manual Page FCC Notice Important Information About This Manual Table of Contents Atapi interface Tape format Glossary Acronyms and measurements Introduction Drive overviewSTT8000A internal drive without mounting brackets Features Typical system configurations Minicartridge technology overviewFlash Eeprom SoftwareReferences About this manual Chapter Title DescriptionSpecifications Physical specificationsOverview STT8000A 3.5-Inch mount general dimensions Power specifications Specification MeasurementPerformance specifications Feature SpecificationSpecification Operational Non-operational Environmental requirementsReliability Mean-Time-Between FailuresMean-Time-To-Repair Recommended tapes Tape capacities and formatsRegulatory compliance TUV & IEC-RHEINLANDBefore you begin InstallationIntroduction Handling guidelinesSetting jumpers Jumper block and jumper settingsInstalling the drive Aligning the drive in the computerMounting dimensions Mounting holes on internal drive without mounting brackets ATA-2 Interface pin assignments Pin Assignment Description SourceREQ Chapter Installation Drive operation and maintenance Front panel LEDUsing Travan cartridges Loading and unloading cartridgesSetting the write-protect switch Travan cartridge write-protect switch-locked positionLoading revised firmware via Seagate firmware cartridge Care and maintenance of the drive and cartridges Caring for tape cartridgesCaring for the drive Capstan Tape Head Troubleshooting Chapter ATA-2 Signals Atapi interfaceATA-2 Interface ATA registers AbrtBits Mnemonic Description Supported ATA Commands Previous Cmd Int ReasonFeature Number Set Feature Commands Atapi Identify Device A1h Atapi Packet Command A0h Atapi interface DSCErase command Inquiry command Bit ByteLoad/Unload command Locate command Log Select command Log Sense command Error Counter Page Read Following table presents the Error Counter Page layoutTape Capacity Page Code Following table presents the Tape Capacity Page layoutMode Select command Mode Sense command Code DescriptionMode Parameter Header Mode Block DescriptorMode Medium Partition Mode Capabilities and Mechanical StatusMode Tape Parameters Read command Read Position command Following table describes the Read Position layoutChapter Atapi Interface Request Sense command Following table describes the Request Sense layout Rewind command Space command Test Unit Ready command Write command Write Filemark command Write Buffer download microcode command Tape format Tape partitioningTrack positions Track numbering Track formatFrames General track layout Tape reference servo pattern BlocksWrite equalization RandomizationChapter Tape format Block diagram Theory of operationsCartridge load mechanism Capstan drive motor assemblyMechanics ChassisSensors and switches Control circuitsHead design Media-Travan minicartridges Travan minicartridgeGlossary Appendix a Glossary Glossary Appendix a Glossary Acronyms and measurements Acronyms and abbreviationsLSI Units of measurement Measure MeaningAppendix B Acronyms and Measurements