Ibm 3590 High Performance Tape Subsystem Models B1A And B11 - IBM AS/400e User Handbook Manual

Removable Storage Media Devices

IBM 3590 High Performance Tape Subsystem Models B1A and B11

The 3590 High Performance Tape Subsystem Model B11 is a rack-mountable unit using high
performance ½-inch tape cartridges as the storage media. The figure above shows two 3590
Model B11s side-by-side in a 9309 rack.
These cartridges use metal particle media, providing a capacity of up to 10 GB. With the
enhanced LZ1 compaction technique of the 3590, this capacity can be increased up to 30 GB
per cartridge.
The tape cartridges used by the 3590 are the same physical size as those used in the 3480
and 3490E but cannot be interchanged between the tape subsystems. Only the high
performance and extended length ½-inch tape cartridges are supported in the 3590.
The 3590 incorporates an advanced longitudinal recording technique that makes eight
passes along the tape media. It writes 16 data tracks at a time to the end of the tape, and
then switches to the next 16 different interleaved tracks and writes back to the beginning of
the tape cartridge. The heads then move down to the next set of tracks and repeat the
process. This provides a total of 128 data tracks.
For greater reliability and data integrity, the 3590 has improved Error Correction Code (ECC)
combined with servo tracks on each tape cartridge. A portion of each tape cartridge is
reserved for error history, which is updated after each use to aid early identification of
potential media problems.
The 3590 Model B11 provides one tape drive and includes an integrated control unit with two
SCSI ports. 3590s shipped prior to 29 January 1999, support a 16-bit fast and wide SCSI-2
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AS/400e System Handbook