Quantum 10K II - Manual (Page 130)

SCSI Description
Quantum Atlas 10K II Ultra160/m SCSI Hard Disk Drives 5–63
MODE SELECT (6) Command (15h) (continued)
Table 5–30 Mode Parameter Block Descriptor — Field Descriptions
Field Description
Density Code Ignored by the drive.
Number of Blocks This field specifies the number of logical blocks on the unit that are affected
by the current MODE SELECT command.
When this field is 0, the MODE SELECT parameters are put into effect for all
logical blocks on the unit.
The maximum value allowed is the total number of initiator-addressable
logical blocks for the value specified in the Block Length field.
A value that is less than the maximum value will decrease the number of
initiator-accessible logical blocks to the amount specified.
Block Length This field specifies the length, in bytes, of each logical sector.
5.14.3.1 Categories of Changeable Pages
The drive’s changeable pages are described on the following pages. The data fields
for each of these pages fall into one of the categories described in Table 5-31.
Table 5–31 Categories of Changeable Pages
Category Description
Fully Supported A field in this category can be modified by the MODE SELECT command, can
be saved, and can affect the drive’s processing. The drive uses the value in the
field and, if the SP bit is set, preserves the new value of the field in non-
volatile memory on the drive. (The PS bit must have been set when the mode
page was returned with a MODE SENSE command.)
Fully Supported fields are underlined in the Mode Parameter Pages shown on
the following pages. The PS bit is underlined (meaning it will be set on a
MODE SENSE command) only if the page is savable.
Temporary A field in this category is fully supported, with one exception; the drive does
not save the field contents. The drive does not give an error indication if an
attempt is made to save a temporary field.
Temporary fields are also underlined in the Mode Parameter Page illustrations
but the PS bit is not.
Ignored A value in this field is never used or validated; it is never looked at by the
drive. Ignored fields are not underlined in the Mode Parameter Pages’ figures
or tables and are not described in the Field Description tables.