structure checksum is the two's complement of the sum of all byte in words 0 through 254 and the byte
consisting of bits 7:0 of word 255. Each byte is added with unsigned arithmetic, and overflow is ignored. The
sum of all bytes is zero when the checksum is correct.
Cylinder high
Cylinder low
Sector number
Sector count
Table 87 DCO error information definition
HITACHI Deskstar & CinemaStar P7K500 Hard Disk Drive specification (Rev 1.1)
invalid word location
invalid bit location (bits (15:8))
invalid bit location (bits (7:0))
error reason code & description
01h
DCO feature is frozen
02h
Device is now Security Locked mode
03h
Device's feature is already modified with DCO
04h
User attempt to disable any feature enabled
05h
Device is now SET MAX Locked or Frozen mode
06h
Protected area is now established
07h
DCO is not supported
08h
Subcommand code is invalid
FFh
other reason
125