| 摘要 |
Records from tapes one and two are merged in a logical sequence on tape three in a two-tape drive system. Prior to the merge operation sequence, control bits, ones and zeros, developed in response to high, low, equal comparisons of the records on tapes one and two, are stored. Then in two successive operations, records, first from tape one and then from tape two, are written on tape three, in sequence as determined by the control bits. While records from tape one are being written, control bits indicating that records from tape two are next in sequence cause zeros to be written on tape three to reserve space for records from tape two. After all records have been written from tape one and zeros have been written to reserve space for records from tape two, a tape mark is written on tape three and tapes one and three are rewound. Tape two is mounted in place of tape one and whenever zeros are read from tape three, records from tape two are inserted. When the tape mark on either tape two or three is detected, the operation is complete.
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