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Disk Media Management
6 - 4
C141-E167
(1) Issuing the MODE SELECT command
The MODE SELECT or MODE SELECT EXTENDED command is issued and the format attributes
on the disk media are specified. The necessary parameters at this time are as follows.
a. Block descriptor
The logical data block size (byte length) is specified in the "Data block length" field. Also, when
desiring to clearly specify the logical data block count, specify that value in the "Data block
count" field. If not, zero may be specified in the "Data block count" field. In that case, the
number of logical data blocks after initialization will be determined by the values specified in the
Format parameters (Page 3) and the Drive parameters (Page 4).
b. Format parameters (Page 3)
Specify the number of spare sectors secured in each cylinder in the "Alternate sector count/zone"
field. It is desirable not to specify a value that is lower than the IDD's default value in this field.
c. Drive parameters (Page 4)
The number of cylinders in the "User Space," cannot be changed. The number of cylinders
necessary to secure the number of logical data blocks specified in the "Data block count" field in
the block descriptor will be allocated to the user space.
(2) Issuing the FORMAT UNIT command
Issue the FORMAT UNIT command and initialize the entire disk media surface.
In this FORMAT UNIT command, the entire disk media surface is initialized using the P List, then
after initialization, the data blocks are verified. If any defective blocks are detected in the Verify
operation, alternate blocks are allocated for those data blocks. Also, the defect position information
for only the defective data blocks detected in the Verify operation is recorded in the G List.
The contents which need to be specified at this time are as follows.
a. CDB specification
Specify "0" in the "FmtData" bit and the "CmpLst" and "000" in the "Defect List Format" field
in the CDB.
b. FORMAT parameters
If the items values in the previous item are specified in the CDB, the Format parameter is not
necessary.