Abstract: A disk drive is disclosed comprising a plurality of servo sectors that define a plurality of tracks, and a head comprising a read element radially offset from a write element. The read element is positioned over a first track, and the first track is read to generate first read wedge repeatable runout (WRRO) values. A first seek operation of the head positions the read element over a second track, and the second track is read to generate first write WRRO values. The first write WRRO values are used to write the first read WRRO values to the first track. A second seek operation of the head positions the read element over a third track, and the third track is read to generate second write WRRO values. The second write WRRO values are used to write the first write WRRO values to the second track.

Abstract: An apparatus and a method for calibrating the write current applied to a write head (110, 114) in a tape drive (100) finds the peak value of the write current applied to the tape head (110, 114) (i.e., the write current value providing the maximum read voltage amplitude on a tape (104)) by indirectly measuring the voltage sensed by a read head (112, 115). The apparatus includes a digital write current control circuit (170, 160) that applies a write current having a magnitude responsive to a digital write current value. An amplifier (190) in a read circuit (180, 182, 184, 190, 196) has a gain responsive to a digital read gain value. The method includes the steps of sampling the output of a pattern detector (146) (e.g., a gap detector) as the digital read gain value is adjusted for each of a number of digital write current data values applied to the write current control circuit (170, 160).