Hitachi HTS542525K9SA00 Specifications page 183

Sector Number This indicates the sector number of the last transferred sector. (L = 0).
In LBA mode this register contains the current LBA bits 0–7. (L = 1)
Cylinder High/Low This indicates the cylinder number of the last transferred sector. (L = 0).
In LBA mode this register contains the current LBA bits 8–15 (Low) and bits16–23
(High). (L=1)
H This indicates the head number of the sector to be transferred. (L = 0)
In LBA mode this register contains the current LBA bits 24–27. (L = 1)
Deskstar 7K160 Hard Disk Drive Specification
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