| 摘要 |
PURPOSE:To eliminate the limitation of access time to an optional record by collecting the sets of logical and physical indexes allotted to each data block and recording them at a prescribed position of a record volume. CONSTITUTION:The data transferred to a control unit 12 from an upper device 10 is stored in a part 28 of a buffer 23 via a channel adaptor 20 and a bus 14. The physical indication formed on the basis of the output signal of a tachometer 33 provided to a reel 32 of a tape recorder 13 and the logical indication obtained by counting 21 the block numbers sent from a marker on a tape are stored in the parts 25 and 27 of the buffer 23 respectively. At the same time, each index is transferred to the device 10 via the adaptor 20. When the recording is over with all data, the device 10 records an index block including plural sets of logical and physical indexes by giving an indication to a record memory system 11. |
