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12. Appendix E
12.1.3.
User Volume Note & User Partition Note
The drive interface supports host application access to the following data structures: the User
Volume Note (UVN) representing user supplied information related to the contents of the
cassette; and the User Partition Note (UPN) representing user supplied information related to
each partition. These structures are contained within the MIC User Data Area and their contents
are application dependent. Applications are not required to maintain this data.
UVN is created by Log Select Page 3Eh Parameter Code 0001h. UPN is created by Log Select
Page 3Eh Parameter Code 0002h + Partition Number. Once UVN and UPN are created they
cannot be discarded except through Mode Select Page 11h that reformats the cassette. Each
UVN and UPN may be overwritten with new data of exactly the same data length. The
exception to this rule is the last data structure within the MIC User Data Area: it can be
expanded or shrunk. The maximum size of a data structure is limited by the current MIC free
byte count, while the minimum size is ONE byte (Log Sense Page 3Dh Parameter Code 0003h).
The internal format of the data is application dependent.
The MIC User Data Area may contain the following combinations of user defined UVN and UPN
structures, where "data X" represents data structures that can be resized and "data A"
represents data structures of fixed size:
0
no data
1
data X
2
no data
3
data A
4
no data
5
data A
6
no data
7
data A
Super High Speed Search Map
12.1.4.
When writing a tape, the drive stores physical positioning information in MIC. This information
makes subsequent fast search operations possible.
Example of Usage
12.1.5.
The information is organized within MIC using fixed size fields for system information and
variable size fields for the user-defined and user-maintained User Data Area. The Sony
SDX-700C provides the SCSI Log Sense and Log Select Vendor Unique Page to access this
information. The page 3Dh is used to access the fixed length fields, while the page 3Eh is used
to access the variable length information in MIC.
The following example shows a two partition case, in which the host application can make use
of up to 779 bytes of space reserved for User Data Area. In case of a 16 kbit version of MIC, the
MIC header consumes 781 bytes, system logs for partitions 0 and 1 utilize 128 bytes, and the
Super High Speed Search Map portion consumes 350 bytes. In this example, the application
uses the entire User Data Area for UVN:
12-2
UVN
UPN for partition 0
no data
no data
data X
data X
no data
no data
data A
data A
UPN for partition 1
no data
no data
no data
no data
data X
data X
data X
data X
SONY AIT-3 drive SDX-700 series Ver.2.1
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