| 摘要 |
PURPOSE:To improve both the using efficiency and the stop position accuracy of a tape by recording the start and end point identifying signals of low frequencies of different pulse numbers at the front and back of a data block on the same track as the digital data. CONSTITUTION:A start point identifying signal 2 of 250msec and about 55 pulses and an end point identifying signal 3 of 100msec and about 22 pulses are recorded at the front and back of a data block 1. An MMB17 is driven by the output of a noise cutting comparator 16, i.e., the signals 2 and 3. At the same time, the number of pulses of signals 2 and 3 are counted by a counter 18. The count number N of the counter 18 is latched by a latch 19 when the final pulse is supplied to a monostable multivibrator 17. A CPU21 reads the contents of the latch 19 and discriminates the start or end point of the block 1 from the number N to control the drive and stop of a cassette tape. |
