Quantum Audio Travan 40 Tape Drive STT3401A - Manual (Page 122)

Chapter 6 Travan 40 tape format
Page 114 Seagate Travan 40 Product Manual
Travan 40 tape format
Introduction
The Seagate Travan 40 drives conform to the Travan 640 and the QIC-3220-MC
recording format standards. These formats are 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 Travan 40 tape format.
Tape partitioning
The drive uses factory pre-written Travan 40 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 0 through 107) and is recorded on all tracks
except the Directory track.
Recording data at 192,000 bits per inch (BPI), the drive can store 20 Gbytes of data
on a Travan 40 cartridge. Using software data compression, these capabilities are
typically doubled.
The recording format and partitioning support Quick File Access (QFA).
Track positions
Each track is written referenced to servo patterns written between the BOT holes
and Load Point on the BOT end of the tape, and between EOT and EW on the EOT
end of the Tape. The servo pattern is written across the entire width of the tape. The
Directory Track has larger guard bands on both sides to allow it to be written without
interfering with its adjacent tracks.
The data tracks are divided into 4 bands with 3 sub-bands each to reduce the time
required to change from track to track. Tracks are grouped into bands, as shown in
the following table:
Band Starting Track Ending Track Direction
1 0 52 Forward
2 1 53 Reverse
3 54 106 Forward
4 55 107 Reverse
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