Seagate STT8000A manual Tape format, Tape partitioning, Track positions

Tape formatChapter 6

Tape format 6

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 Page 63