HP Integrity NonStop H-Series - Manual (Page 13)

Chapter One – Introduction
Tandem 5142-xSE Rackmount Tape Subsystems User Guide 3
• 1.0MB/s uncompressed
• 2.0MB/s compressed
1.3.4 SCSI bus data transfer rates (burst):
• 3MB/s asynchronous
1.3.5 Interface:
• SCSI-2, differential
1.3.6 LCD and control panel:
• Intelligent front end, backlit, supertwist LCD
• Advanced drive test and exercise function
• Firmware upgrade function
1.3.7 Drive Rated Performance:
• Recording density: 122,000 BPI
• Error rate: <10
-15
• Buffer size: 2MB
• Load time: <20 seconds
• Unload time: 80 seconds with 125m tape
1.4 SCSI Compatibility
The 5142-xSE tape drive subsystem's interface complies with the American National Standard Institute
(ANSI) standard X3T9.2 (SCSI-2). This standard defines the specifications for the Small Computer
System Interface (SCSI). As defined by the ANSI, SCSI is essentially an input/output bus for
interconnecting computers and peripherals.
1.5 DDS-3 Format and Compatibility
The 5142-xSE's DDS-3 format is an extension of the DDS-1, DDS-DC and DDS-2 formats. DDS formats
have been developed to provide data storage for computers by using and extending DAT technology.
DDS-3 allows 12GB of uncompressed data to be stored on a DDS-3 (125m) tape cartridge. Data
compression increases this storage capacity. A compression ratio of 2:1 raises the capacity to 24GB.
• The DDS-3 format allows compressed data to be stored in a way that maintains the full
functionality of the DDS-1, DDS-DC and DDS-2 formats, and ensures backward compatibility in
reading and writing with existing DDS drives.
• The drive automatically decompresses DCLZ data, even if data compression is inactive.
• DDS-2 tapes written on a DDS-3 tape drive are readable by a DDS-2 tape drive; however, a DDS-3
(125m) is NOT readable on a DDS-2 drive.