Appendix H: Glossary - Sony SDX-700C Product Specifications Manual

15. Appendix H

15. APPENDIX H: GLOSSARY

This glossary includes many terms that are useful when working with the SONY DDS tape drive. Not all terms are
used within this manual.
Amble: A frame used to separate groups. It has a Logical Frame Number of ZERO. The Main Data Area contains
only a valid header.
ANSI: American National Standards Institute, which sets standards for, amongst other things, SCSI and the safety of
electrical devices.
ATF: Automatic Track Finding
Beginning Of Partition (BOP): The position at the beginning of the permissible recording region of a partition. If
only one partition is defined, this position is typically equivalent to the beginning-of-medium. (BOM)
Beginning Of Medium (BOM): The extreme position along the medium in the direction away from the supply reel
which can be accessed by the device.
Bit Error Rate: Number of errors/Total number of bits written or read
Block Error Rate: Number of errors/Total number of blocks written or read
BOM: Beginning Of Media
BOT: Beginning Of Tape
Buffered mode: A mode of data transfer in write operations which facilitates tape streaming, as reported in the
Mode Select parameter.
Device Area: The first area on the tape used by the drive for drum spin-up and testing.
Drop-out: An area of tape where the signal level of the media has fallen off to a level where data recovery is no
longer possible.
Early Warning: A device computed position near but logically before the end-of-partition. See the REW bit in the
Mode Select Device Configuration page.
ECC: Error Correction Code
End Of Data (EOD): End of data in a partition a special format group written after all current user data.
End Of Medium (EOM): The extreme position along the medium in the direction away from the take-up reel which
can be accessed by the device.
End Of Partition (EOP): The position at the end of the permissible recording region of a partition. May be the same
as end of media.
EOD: End Of Data
EOM: End Of Media
EOP: End Of Partition
EOT: End Of Tape
Error Rate Log: The Error Rate Log exists in RAM in the SDX-700C and maintains a history of hard (un-correctable)
and soft (correctable by RAW or C3 ECC) errors which have occurred since the last tape load.
Fast Searching: The process of reading just the ID areas to locate an item on the tape at a speed up to 75 times
faster than normal read speed.
Fault Log: The Fault Log is stored in RAM in the SDX-700C and holds a record of Self-Test failures and all problems
which have been met during normal operation.
Frame: Two adjacent tracks, one A channel and one B channel.
File-mark: A mark written by the host. It does not necessarily separate files. It is up to the host to assign a meaning
to the mark. Consist of a special recorded element within a partition, containing no user data, which provides a
segmentation scheme.
SONY AIT-3 drive SDX-700 series Ver.2.1 15-1