IBM IC35L040AVVN07-0 - 40GB IDE Deskstar 120GXP 7200RPM UATA-100 07N9682 Specifications page 193

Output Parameters To The Drive
Sector Count Time-out Parameter. If it is 0, the automatic power down sequence is disabled. If
it is nonzero, the automatic power down sequence is enabled. The time-out
interval is shown below:
Value Time-out
0 Timer disabled
1-240 Value x 5 seconds
241-251 (Value-240) x 30 minutes
252 21 minutes
253 8 hours
254 21 minutes 10 seconds
255 21 minutes 15 seconds
When the automatic power down sequence is enabled, the drive will enter
Standby mode automatically if the time-out interval expires with no drive access
from the host. The time-out interval will be reinitialized if there is a drive access
before the time-out interval expires.
Deskstar 120GXP hard disk drive specifications
179