A system and method of extending the position error signal for a disk drive storage
system using two digital-to-analog converters in a summing junction, including
a typical A-B signal and a track error signal scaled to match a gain of the A-B
signal. A track error is calculated. The track error is output to a second digital-to-analog
converter. The A-B signal is inverted according to the least significant bit of
the grey code of a disk track being read. The inverted A-B signal is output to
a first digital-to-analog converter. The inverted A-B signal and the track error
are combined using a summer to generate a combined signal. The combined signal
is used to generate an extended position error signal.