HP A3716A DDS-3 Autoloader User's Manual - 3716-96001

Glossary-5
time-tracking
A technique of ensuring that the read head stays in the center of the track
that it is reading. The drive measures the time it takes to reach a particular
point on the track, and if this time is less than or greater than its proper
value, the drive adjusts the tape speed to compensate. In HP DDS-3 drives,
time-tracking replaces the Automatic Track Following (ATF) used in DDS-1
and DDS-2 drives, and allows more of each track to be available for data
storage. Note that the drive still writes ATF signals when writing DDS-1 and
DDS-2 cartridges to ensure backwards compatibility.