Magnetic data storage can be viewed as a data communication system. This is not a sUlprising view, considering that data storage is essentially the transfer of data between different times. The past decade has indeed seen rapidly growing interest in applying improved coding and detection techniques to magnetic data storage, a traditional approach to enhance performance of communication channels. Since its inception in the 1930's, the magnetic recording industry has achieved impressive progress in data capacity. This has been made possible mainly by innovations and advances in heads and media...