| 摘要 |
PURPOSE:To avoid an unnecessary seeking action when an access is indicated to a defective track by attaining an access to a substitute track just with a seeking action for the 2nd and subsequent accesses to the defective track. CONSTITUTION:A checking circuit 2 checks whether the tack designated by an access indication to a magnetic disk is registered in a memory 1 or not. If no registration is detected, the header part of a data block designated by an access indication given from the magnetic disk is read out. Then an access is given to the data block designated based on the track address shown at said header part if a defect is displayed at the header part, and the access designated by said access designation substitutes. At the same time, the track address designated by said access designation and said correct track address are registered to the memory 1 in the form of a defective and substitute track addresses respectively. Then a control circuit 3 performs control to give an access to the data block based on the registered substitute track address in case the circuit 2 detects the above-mentioned registration. |
