MAGNETIC DISK CONTROL SYSTEM

PURPOSE:To decrease the distance required for accessing and then to reduce the revolution queuing time, by calculating a middle sector address from the start and final sector address and storing the calculated sector address in the form of the bit information. CONSTITUTION:The sector start and final addresses to which an access is given are written to registers 10 and 11. A process sector register 13 turns on only the bit that corresponds to an access subject address after turning off all bits. A magnetic disk is read to check whether the bit of the register 13 corresponding to the read-out sector address is turned on or not. If this bit is on, the data is transferred by a DMA. After this transfer is over, the bit of the register 13 is turned off. It is possible to start reading at any sector when the data is read out of the continuous sectors.