Mfm Data Marginalization
Original Publication Date: 1984-Dec-01
Included in the Prior Art Database: 2005-Feb-06
The circuitry shown above in combination with the procedure described below can be used to increase the efficiency and reduce the cost of disk surface analysis. This procedure marginalizes the phase relationship of data to its window and can be used with existing VFO design. The circuitry shown above can be used as part of the manufacturing test procedure, or can be permanently incorporated and used under system program control. The present procedure uses the VFO "Address Mark Found" signal to enable a delay to be inserted in alternating date pulses that are being sent from file. When the delay is inserted in the commonly used tri-bit pattern (worst-case peak shift pattern), media problems can be revealed by CRC (cyclic redundancy check) errors.