Head Position Recalibration for Storage Disk Drive
Original Publication Date: 1981-Sep-01
Included in the Prior Art Database: 2005-Feb-12
A Present Cylinder Number (PCN) register of a storage disk controller indicates to the using system the current position of the magnetic head. After the system is powered on or an accessing error has occurred, it is necessary to recalibrate the PCN register to correspond to the present physical head position. This is accomplished by issuing a READ ID command to obtain the current track number. Step pulses to the magnetic head track-stepping drive are disabled and a SEEK to the current track is performed. Since the magnetic head does not move during the SEEK operation, when the SEEK is complete, the PCN register contains the current track number.