Patent ID: 6862149

Claim:
A method of locating a position on a linear data storage medium onto which data are to be written, said method comprising the steps of: transporting said linear data storage medium past a read head; reading linear position data describing a linear position along said linear data storage medium; determining an approximate position of an append position from which to start writing data by responding to the read linear position; having found said approximate position of said append point, reading an absolute C 1 code word quad identifier number to identify individual C 1 code word quads along the length of said data storage medium; comparing said read absolute C 1 code word quad number with a target absolute C 1 code word quad number; finding a correspondence between said read absolute C 1 code word quad number and said target absolute C 1 code word quad number; if a match between said read absolute C 1 code word quad and said target absolute C 1 code word quad number is found, then generating an interrupt signal to interrupt transport of said data storage medium past said read head; and then commencing a write operation at a position on the medium where said read absolute C 1 code word quad number matches said target absolute C 1 code word quad number.