| 摘要 |
A compatible apparatus capable of reproducing digital data from magnetic tape cassettes employing two different recording schemes such as, typically, NRZI and write equalization. A series of common reproduce circuit elements (e.g. an attenuator, automatic grain control, low pass filter, and shaping circuit) are connected to a magnetic transducer via a preamplifier for use in processing the transducer output signal representative of both NRZI and write equalized data recovered from both types of tape cassettes. Serially inserted in the series connection of the common reproduce circuit elements is a parallel connection of a first exclusive reproduce circuit element (e.g. a differentiating amplifier) used exclusively for reproduction of the NRZI data, and a second exclusive reproduce circuit element (e.g. a flat amplifier) used exclusively for reproduction of the write equalized data. As each loaded tape cassette is automatically identified as being of the NRZI or write equalization type, the required one of the first and second exclusive reproduce circuit elements is switched into serial connection with the common reproduce circuit elements. Most of the reproduce circuit elements can thus be used in common for the processing of both NRZI and write equalized data.
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