IBM IC35L036UWDY10 Hard Drive Specifications - Page 99

8.8.1.2 Block Descriptor Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7 Number of Blocks (MSB) Density code = 0 Block Length (LSB) Figure 84. MODE Parameter Block Descriptor The Block descriptor provides formatting information about the Number of Blocks (user addressable) to format at the specified Block Length. ! Number of Blocks When used with the MODE SELECT command, the Number of Blocks field must be - Zero to indicate not to change available blocks - 0xFFFFFFFF to indicate all available blocks - The exact number of blocks in the data area of the drive, which can be obtained with the MODE SENSE - The number of blocks less than exact one, in order to CLIP the number of blocks Any other value is invalid and causes the command to fail with CHECK CONDITION status. When used with the MODE SENSE command, the field contain exact number of blocks. ! Block Length When used with the MODE SELECT command, the Block length field must contain the value from 512 to 528 (2 bytes step) or zero. Otherwise the drive will terminate the command with CHECK CONDITION status. A Format Unit command is required to cause these parameters to become current only if the block length parameter is different from the current block length. When used with the MODE SENSE command, the field is dependent on how the media is currently formatted. Ultrastar 146Z10 hard disk drive specifications 83