ACCESS SYSTEM FOR DATA BLOCK

PURPOSE:To improve the processing performance by applying access without entire intervention of a control unit at a low speed access utilizing a succeeding logical address the same as the high speed access utilizing a physical address. CONSTITUTION:When a physical address is reached by the high speed access, an end interruption is applied to a control unit 2, which is connected to the control. Then one block is read in forward/reverse direction, the logical address of the block is recognized by the control unit 2 to obtain so as to reach an object data block by which direction (forward or reverse) and how many blocks to be skipped. The control unit 2 gives a command based on the result to the drive unit 5 and is connected from the drive unit again, and the drive unit 5 uses the command information to skip a prescribed number of data blocks and to position itself to the object data block, and gives an end interruption to the control unit 2. Then the control unit 2 is disconnected from the drive unit 5 and in the free state.