| 摘要 |
PURPOSE:To simplify a modulating-demodulating circuit by enabling high-speed data transfer by recording a discrimination signal for a change in data from ''1'' to ''0'' or reverse change only when the data change from ''1'' to ''0'' or vice versa in recording digital signal data on an audio cassette tape acoustically. CONSTITUTION:Signal processing part 1 constituting a modulating circuit is provided with terminal 2, to which a cassete recorder is connected, via resistance R1, and to this terminal 2, the recorder is connected, so that levels H and L when signals of logic values ''0'' and ''1'' are equal in length and change from ''0'' to ''1'' or ''1'' to ''0'' will be detected at the edges of the signals and recorded. Further, a demodulating circuit is simply composed of connection terminal 2 for a recorder, resistance R2, transistor TR, and signal processing part 1 and the edge of the recorded signal from ''0'' to ''1'' or ''1'' to ''0'' is detected by TR to perform data reproduction. |
