Performance evaluation of the disk drive industry´s second-generation partial response maximum likelihood data channel

The latest generation of partial-response maximum-likelihood data channel, recently made available in the IBM 0664 2 Gbyte 3.5 inch disk drive, are examined, and how well it performs its base operation of extracting data from the disk as well as how well it has begun to put other potential sampling detection advantages into practice is reported. Beyond the data rate improvements over the predecessor channel, this latest offering, referred to as the PRDF channel for its expanded digital filter complexity allows a disk drive to perform self-test and self-diagnostics. The use of self-test capability is described as a tool for obtaining precise equalization over all data areas of the 0664 disk drive. The self-diagnostic aids are discussed as a method of reducing the probability of data loss in a disk drive