A method for writing servo onto a disk of a hard disk drive with a servo
writer. The method includes writing a plurality of spiral servo signals
onto a disk. The spiral servo signals include a plurality of short
spirals separated by unequal distances. The short spirals are detected by
determining the unequal distances and used to write a plurality of servo
patterns. The unequal distances provide information of the short spirals
at different quadrants of the disk. The distances between a bank of odd
short spirals is different than a bank of even short spirals which allows
the servo writer to determine whether the bank is odd or even without
switching banks. Either the even or odd bank of short spirals can be used
to locate a starting reference point from which the servo writer can
count spirals and write A, B, C and D servo bursts.