Filter
Top Products
4.1 Mode Parameters
C141-E167 4 - 15
a. Parameters for specifying alternate processing areas for defective blocks (bytes 2 to 9)
The following 4 parameters specify the position and number of spare sectors for performing
defective block alternate allocation processing on the disk media. See Chapter 3, "Data Format"
of Product Manual for details of the IDD's alternate block processing.
• Track count/zone
This parameter specifies the number of tracks a unit for alternating blocks. The INIT
cannot clearly specify this value. The IDD ignores the specification for this bit. If the
value of the Active Notch in Page C is 0, the “Number of tracks a cell” is reported for the
MODE SENSE and MODE SENSE EXTENDED commands.
If not, the total number of track of the zone which is specified as the Active Notch is
reported.
• Alternate sector count/zone
This parameter specifies the number of sectors per one cell as the number of spare sectors
secured for use as alternate blocks. In the IDD, this parameter indicates the number of
spare sectors secured in each cell. The maximum permissible value of this parameter either
the "number of physical sectors per track in the last cell - 1" or "84", whichever is smaller.
It is possible for the INIT to vary this parameter within a range of 0 to the maximum
permissible value. When a value which exceeds the maximum permissible value is
specified, the IDD performs rounding down of the parameter and sets a value equal to this
parameter's maximum permissible value. If the above rounding processing is performed, a
CHECK CONDITION status (RECOVERED ERROR [= 1] / Rounded parameter [37-00]
is reported for that command.
• Alternate track count / zone
This parameter specifies the area secured for alternate blocks as the number of tracks per
one cell. It is impossible to change this parameter. When a value other than zero is
specified in this field, the IDD performs rounding down processing of this parameter and
always sets this parameter value at zero.
• Alternate track count / drive
This parameter specifies the area secured for alternate blocks as the number of tracks per
disk drive. In the IDD, this parameter indicates the number of tracks in the spare area
secured as alternate cells. This value is fixed at a value that equals the number of tracks per
cylinder multiplied by the number of zones in the IDD. This parameter cannot be changed
by the INIT.
b. Parameters specifying track format (bytes 10, 11)
• Sector count/track
This parameter specifies the number of physical sectors per 1 track. In the IDD, the number
of physical sectors in a track is set unilaterally according to the data format specified by the
"Data Block Length" parameter in the block descriptor or the "Data byte length/Physical
sector" parameter in this page descriptor, so this parameter cannot be changed. The IDD
disregards the value specified in this field. This parameter indicates the value of zone
specified in Active Notch of Page C. If it is 0, this parameter indicates the value in zone 0.