Patent ID: 7957089

Claim:
A sequential data storage medium, comprising a sequence of a plurality of servo patterns encoded in a non-data region, wherein each of said servo patterns comprises: a first burst comprising a first pulse, a second pulse, a third pulse, a fourth pulse and a fifth pulse; a second burst comprising a sixth pulse, a seventh pulse, an eighth pulse, a ninth pulse and a tenth pulse; wherein: the widths of said plurality of pulses, in combination with the spacings between said plurality of pulses, encode two bits of data; said first pulse comprises a first magnetic phase shift and a second magnetic phase shift; said second pulse comprises a third magnetic phase shift and a fourth magnetic phase shift; said third pulse comprises a fifth magnetic phase shift and a sixth magnetic phase shift; said fourth pulse comprises a seventh magnetic phase shift and an eighth magnetic phase shift; said fifth pulse comprises a ninth magnetic phase shift and a tenth magnetic phase shift; said sixth pulse comprises an eleventh magnetic phase shift and a twelfth magnetic phase shift; said seventh pulse comprises a thirteenth magnetic phase shift and a fourteenth magnetic phase shift; said eighth pulse comprises a fifteenth magnetic phase shift and a sixteenth magnetic phase shift; said ninth pulse comprises a seventeenth magnetic phase shift and an eighteenth magnetic phase shift; and said tenth pulse comprises a nineteenth magnetic phase shift and a twentieth magnetic phase shift; said first magnetic phase shift and said third phase shift are separated by a first separation; said third magnetic phase shift and said fifth phase shift are separated by a second separation; said fifth magnetic phase shift and said seventh phase shift are separated by a third separation; said seventh magnetic phase shift and said ninth phase shift are separated by a fourth separation; said eleventh magnetic phase shift and said thirteenth phase shift are separated by a sixth separation; said thirteenth magnetic phase shift and said fifteenth phase shift are separated by a seventh separation; said fifteenth magnetic phase shift and said seventeenth phase shift are separated by a eighth separation; said seventeenth magnetic phase shift and said nineteenth phase shift are separated by an ninth separation; wherein for a first servo pattern: said first separation, said third separation, said sixth separation, and said eighth separation, are equal in length; said second separation, said fourth separation, said seventh separation, and said ninth separation, are equal in length; said first servo pattern encodes a value “10”.