A tape drive and method of identifying write velocity during reading are provided.
When a track is being read, a lead-in code of the data signal is processed prior
to determining the data stream. The lead-in code identifies the velocity with which
the track data were written. The equalization/detection channel is adjusted based
on the identified velocity to compensate for write channel transfer function variation.
The lead-in code is coded in a way that is reasonably immune to write channel transfer
function variation such that the lead-in code is comprehended prior to adjusting
the equalization/detection channel.