Seagate STT8000A manual Tape format, Tape partitioning, Track positions

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Tape formatChapter 6

Tape format

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Introduction

The STT8000 ATAPI minicartridge drive conforms to the QIC-3095-MC recording format standard. This format is for streaming magnetic tape in a minicartridge that is to be used for information interchange among information processing systems, communication systems, and associated equipment.

This chapter provides an overview of the tape format used by the STT8000 ATAPI minicartridge drive.

Tape partitioning

The drive uses factory pre-written Travan TR-4 media. The tape is always divided into two partitions:

Partition 1 is the directory partition and is recorded on the Directory track only.

Partition 0 contains the data (tracks 1 through 71) and is recorded on all tracks except the Directory track.

Recording data at 67,733 bits per inch (BPI), the drive can store 4.0 GB on the data partition of one 900-foot long, 0.315-inch (8.0 mm) wide Travan TR-4 tape. Using software data compression, these capabilities are typically doubled.

The recording format and partitioning support Quick File Access (QFA).

Track positions

The centermost track is called the Directory Track and has larger guard bands on both sides of it to allow it to be written without interfering with its adjacent tracks.

Track zero is the track immediately below the Directory Track. The even numbered tracks are positioned sequentially below track 0. Thus, track 2 is below track 0, and track 4 is below track 2, and so on down to track 70, which is the closest to the reference edge of the tape. (The reference edge is the edge of the tape that is nearest to the baseplate of the cartridge.)

Track 1 is the track immediately below the Directory Track. The odd numbered tracks are positioned sequentially up from track 1. Thus, track 3 is above track 1, and track 5 is above track 3, and so up to track 71, which is the closest to the upper edge of the tape.

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 Drive overview IntroductionSTT8000A internal drive without mounting brackets Features Minicartridge technology overview Typical system configurationsReferences Flash EepromSoftware Chapter Title Description About this manualOverview SpecificationsPhysical specifications STT8000A 3.5-Inch mount general dimensions Specification Measurement Power specificationsFeature Specification Performance specificationsEnvironmental requirements Specification Operational Non-operationalMean-Time-To-Repair ReliabilityMean-Time-Between Failures Tape capacities and formats Recommended tapesTUV & IEC-RHEINLAND Regulatory complianceHandling guidelines InstallationIntroduction Before you beginJumper block and jumper settings Setting jumpersAligning the drive in the computer Installing the driveMounting dimensions Mounting holes on internal drive without mounting brackets Pin Assignment Description Source ATA-2 Interface pin assignmentsREQ Chapter Installation Front panel LED Drive operation and maintenanceLoading and unloading cartridges Using Travan cartridgesTravan cartridge write-protect switch-locked position Setting the write-protect switchLoading revised firmware via Seagate firmware cartridge Caring for the drive Care and maintenance of the drive and cartridgesCaring for tape cartridges Capstan Tape Head Troubleshooting Chapter ATA-2 Interface ATA-2 SignalsAtapi interface Abrt ATA registersBits Mnemonic Description Previous Cmd Int Reason Supported ATA CommandsFeature Number Set Feature Commands Atapi Identify Device A1h Atapi Packet Command A0h DSC Atapi interfaceErase command Bit Byte Inquiry commandLoad/Unload command Locate command Log Select command Log Sense command Following table presents the Error Counter Page layout Error Counter Page ReadFollowing table presents the Tape Capacity Page layout Tape Capacity Page CodeMode Select command Code Description Mode Sense commandMode Block Descriptor Mode Parameter HeaderMode Capabilities and Mechanical Status Mode Medium PartitionMode Tape Parameters Read command Following table describes the Read Position layout Read Position commandChapter 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 Track positions Tape formatTape partitioning Frames Track numberingTrack format General track layout Blocks Tape reference servo patternRandomization Write equalizationChapter Tape format Theory of operations Block diagramChassis Capstan drive motor assemblyMechanics Cartridge load mechanismHead design Sensors and switchesControl circuits Travan minicartridge Media-Travan minicartridgesGlossary Appendix a Glossary Glossary Appendix a Glossary Acronyms and abbreviations Acronyms and measurementsLSI Measure Meaning Units of measurementAppendix B Acronyms and Measurements