An extended sync pattern, which is comprised of a pattern portion at the end of a preamble pattern recorded immediately before an original sync pattern in a sector and the original sync pattern, is used in a sync detecting operation in place of the original sync pattern. This sync detecting operation...http://www.google.de/patents/US20010010604?utm_source=gb-gplus-sharePatent US20010010604 - Sync detector for use in data storage system for detecting extended sync pattern
