DATA BLOCK RETRIEVAL DEVICE FOR MAGNETIC TAPE DEVICE

PURPOSE:To control plural magnetic tape device by means of one data block retrieval device by permitting a simultaneous operation means to simultaneously operate plural magnetic tape device connected to the data block retrieval device, permitting a switching means to sequentially switch block ID information from the magnetic tape device and transmitting it to controller. CONSTITUTION:The controller 5 reads block ID information in plural data blocks recorded in a magnetic tape, and controls the magnetic tape devices in such a way that they position the magnetic tape in the specific data block which a host device 1 is indicated. A simeeltaneous operating means 8 simultaneously operate plural magnetic device 6 and 7. the switching means 9 transmits to the controller block ID information from one magnetic tape device between plural magnetic tape devices 6 and 7, and then it sequentially switches block ID information from the other magnetic tape device and transmits it to the controller 5. With one controller 5, plural magnetic tape device 6 and 7 are sequentially controlled and the block ID signals of plural magnetic tapes which plural magnetic tapes 6 and 7 read can be retrieved.