Hitachi IC25N040ATMR04-0 - Travelstar 40GB Laptop Hard Drive 9.5mm 2.5 Inch Notebook HDD Specifications page 141

LBA High/Low
H
This indicates the cylinder number of the last transferred sector. (L = 0)
In LBA mode, this register contains current LBA bits 8–15 (Mid), 16–23 (High). (L = 1)
This indicates the head number of the last transferred sector. (L = 0)
In LBA mode, this register contains current LBA bits 24–27. (L = 1)
Travelstar 80GN Hard Disk Drive Specification
131