MAGNETIC TAPE CONTROLLER

PURPOSE:To provide a magnetic tape control device capable of executing accurate positioning independently of a block searching direction in a computer system equipped with a magnetic tape device as a storage device. CONSTITUTION:The magnetic tape control device is provided with a high speed searching part 6 for searching physical blocks from the magnetic tape device 12, a logical searching part 7 for searching logical blocks from the device 12 after searching the physical blocks, a final block checking part 5 for checking the validity of a block finally read out by the searching part 7, a block number searching part 10 for searching the recognition of a logical block number based upon an instruction from the checking part 5, and a position compensating part 2 for compensating a deviation from an objective position based upon the searching direction and searching frequency of the searching part 10.