14. Appendix F
SONY AIT-1 Turbo drive SDX-470V series Ver.1.0
14-4
Device
Area
System
Area
Data
Area
EOD
Area
Write Volume Info. & System Log
Rewind
5s
(0s)
30s
(17s)
Search System start of Area
7s
Cassette OUT
Cassette UP
Threading
1s
7s
(9s)
10s
(0s)
Rewind to Middle of Device Area
Figure F-4: Tape Unload with and without MIC
Device
Area
System
Area
Data
Area
EOD
Area
Search System Area
Read Volume Info. & System Log
Stand by here
Cassette IN
Cassette DOWN
Threading
1s
7s
5s
(0s)
4s
17s
(12s)
Figure F-5: Tape Load with and without MIC
14.2.2.
Super High Speed Search
The Super High Speed Search Map maintained by the drive contains physical medium positioning information that
allows the AIT drive to conduct super high speed, bi-directional searches using the 120 inches per second speed
mode previously employed only for cartridge rewind. Once the drive reaches the tape segment identified by the MIC
information, its speed drops to the standard search speed of 60 inch per second, and then the drive locates the
tape’s precise position by reading the identifier blocks directly from the tape. This technique can reduce the average
access time to as little as 27 seconds, a 50% improvement.
The map is transparently managed by the drive. It is created at the bottom of MIC’s memory address. The map
cannot be cleared nor discarded, unless the Mode Select command is issued instructing the drive to re-format the
cassette.
