PURPOSE: To ensure the date protection and the security protection by storing a read attribute as to whether the read is permitted or inhibited on each storage unit an attribute storage means and permitting or inhibiting the read of each storage unit with a control means in accordance with the stored read attribute.
CONSTITUTION: A command such as read and write, etc., and a data are sent by a host computer H to a microprocessor 3, where the command is interpreted by the processor 3 to send the required command and data to a magnetic disk controller 2 and a mechanism controller 4. The command received by this controller 2 is passed to a read/write control part 6, and magnetic disk device 5 is controlled in read and write by the control part 6 utilizing received head address, read and write signals. That is, if the control part 6 is set as read inhibit or write inhibit against a track number sent to the control part 6, the command to be sent to the device 5 is not transmitted to the device 5 by the controller 6.
KOBIYAMA TOMOHISA
TSUNEHIRO TAKASHI
