| 摘要 |
<p>PURPOSE:To improve the effective use of a subsystem for cross-call of magnetic tape by delivering the information of end even through a non-corresponding controller system based on the information on the state display bit, etc. given from a magnetic tape device when an instruction is through. CONSTITUTION:A magnetic tape device 30 which works in response to an instruction given from a magnetic formatter 20 delivers the state bit which is set at '1' via a comparator 207, an end reporting circuit, 108, etc. when the coincidence is secured between the number of instructed skips of a register 204 and the output delivered from a counter 205 which counts the block numbers of a magnetic tape for each reading in the form of the information of end. Thus an AND gate 109 of the formatter 20 is opened and the information of end is delivered by a comparator 108 which confirms the coincidence of instruction blocks given from a block control memory 101 and a shared memory 200, an end information circuit 110, etc. and sent to a host device via a magnetic tape controller 10. The state bit, the read block number sent from the memory 200, etc., are also supplied to a formatter 21 of a control system that is delivering no instruction. Then the information of end is sent immediately from said control system when its corresponding control system is busy. This improves the effective use of this system.</p> |
