PURPOSE: To access continuous sectors without changing the constitution of a device by starting the retrieval of the succeeding sector physically before the reception of the succeeding command after the execution of a read command or the like for one sector.

CONSTITUTION: In a magnetic disc control device, a seak command from a control program is stored in a command register 21 and transferred address information is stored in an address register 22. When the command is stored in said register 21, a control circuit 27 decodes the command and checks whether the command is a read or write command, and the readout address information is compared with the address information stored in the register 22 by a comparator 26 through a serial/parallel converter 24. The coincidence of the compared result is inputted to the control circuit 27 and a data area in the sector is read out and transferred to a host device through said converter 24 and a data register 25. After the synchronization of the sector, the access operation is started continuously.