Mode - Quantum DLT 8000 Product Manual

MODE SELECT Command (6) / (10) (15h) / (55h) (continued)
Table 5–38 Mode Parameter Block Descriptor — Field Descriptions (continued)
Field Name
Block Length
5.9.1.3 Mode Page Descriptors
Following the MODE SELECT command's Mode Parameter Block Descriptor are the
MODE SELECT pages, each of which sets a different device parameter. Each mode page
has a 2-byte header that identifies the page code and indicates the number of bytes in
that page.
Bit 7
Byte
0 PS (0)
1
2 - n
Figure 5–40 MODE SELECT Page Descriptor — Data Format
Table 5–39 MODE SELECT Page Descriptor — Field Descriptions
Field Name
PS
Additional Page Length
Page-Defined or Vendor
Unique Parameter List
Description
This field specifies the length, in bytes, of each logical block transferred
over the SCSI bus. A block length of 0 indicates that the length is variable
(specified in the I/O command). Any value other than 0 indicates the
number of bytes per block to use for READ, WRITE, and VERIFY
commands that specify a "fixed" bit of 1 (i.e., fixed block mode) which
also causes the transfer length in the command descriptor block to be
defined as a block count. If fixed bit is not equal to 1, this field is
ignored.
6 5
0
Additional Page Length
Page-Defined or Vendor Unique Parameter List
Description
Parameters Savable. For the MODE SELECT (6) (10) commands, this
field is reserved (0).
Indicates number of bytes in that page (not including bytes 0 and 1).
Information in this field depends on the mode page. Refer to Sections
5.9.2 through 5.9.9.
Quantum DLT 8000 Tape System
4 3
Page Code
SCSI Commands
2 1 0
5-79