MAGNETIC TAPE CONTROLLER

PURPOSE:To perform the reception of another MTU while processing of mark detection for one magnetic tape unit (MTU), by providing an exclusive reading circuit which is started from the indication of a microprocessor and then reads specific codes. CONSTITUTION:The 2nd block/tape mark detecting circuit 18 is provided with a counter and a clock mechanism, for example, and can confirm and detect the tape mark as hardware. For example, when a tape controller MTC receives the processing indication of the tape mark to the 1st MTU8, the data of the 1st MTU is processed in the path of a receiver 10 selection circuit 11 block/ tape mark detecting circuit 18 and the tape is driven until the mark is detected. Even if the write/read command to the 0th MTU5 is received by the MTC during the processing, a microprocessor 17 can process for the 0th MTU5 exclusively. Thus, even if one set out of MTUs performs mark processing, the data processing for other MTUs can be executed.