Sony DDS-4, Руководство по описанию продукции

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6 - 52 SONY SDT-10000/SDT-11000 DDS Tape Drive
6. COMMAND SPECIFICATION
Bit 7 6 5 4 3 2 1 0
Byte
0 Mode Data Length
1 Medium Type (00h)
2 WP Buffered Mode Speed (00h)
3 Block Descriptor Length (08h)
4 Density Code
5 (MSB)
6 Number of Blocks (00 00 00h)
7 (LSB)
8 Reserved
9 (MSB)
10 Block Length
11 (LSB)
The MODE SENSE data contains a four-byte header, followed by one eight-byte block descriptor, followed by zero or
more variable length pages, depending on the Page Code and the Allocation Length.
Table 6-36: MODE SENSE data
Mode Data Length:
The mode data length specifies the length in bytes of the following mode sense data that is available to be transferred
during the DATA IN phase. The mode data length does not include itself but does include the total length of all
requested MODE SENSE pages.
Media Type:
The media value will be zero as only one media type is supported.
WP:
A Write Protected bit of zero indicates that the tape is write enabled. A Write Protected bit of one indicates that the
tape is write protected.
Buffered Mode:
if this bit is set to zero, the drive will not report a GOOD status on WRITE commands until the data blocks are
actually written on the tape. If set, the drive is in buffered mode and may report a GOOD status on WRITE
commands as soon as the data block has been transferred to the drive’s buffer. One or more blocks may be buffered
prior to writing to the tape.
Speed Field:
will return zero as the drive only supports one speed.
Block Descriptor Length:
returns a value of 8, which specifies the length in bytes of the following Block Descriptor. The drive only returns a
single Block Descriptor.
When the DBD is one, the Block Descriptor Length in the parameter header is set to 0.
MODE SENSE