Seagate Technology 10002475-003, Product Description Manual

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Product Description Manual Page 55
Tape Format
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 prewritten Travan TR-4 media. The tape is always
divided into two partitions:
z Partition 1 is the directory partition and is recorded on the Directory track
only.
z 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.
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