Claims
- 1. In an electronic musical instrument, wherein information representative of the actuation of selected switches corresponding to associated notes of the musical scale is furnished by a multiplex circuit in the form of a time-division multiplexed signal including a cyclically repeating sequence of time slots associated respectively with such switches, and in which a pulse in a time slot is indicative of the actuation of the switch associated with that time slot, a processing circuit including in combination:
- first and second signal channels;
- delay circuit means in said first signal channel having a delay period equal to N sequences of time slots, where N is a positive integer;
- inverter circuit means in one of said signal channels;
- means for supplying said multiplexed signal to the inputs of said first and second signal channels;
- coincidence gate means with first and second inputs, the first input coupled with the output of said first signal channel and the second input coupled with the output of said second signal channel, for passing pulses in time slots of said time-division multiplexed signal only when a predetermined relationship of the signals applied to the first and second inputs thereof exists.
- 2. The combination according to claim 1, wherein said delay circuit means comprises a shift register circuit shifted at the pulse rate of said multiplexed signal and having a number of stages equal to the number of time slots in N sequences of time slots.
- 3. The combination according to claim 2, wherein said means for supplying said multiplexed signal comprises a digital multiplex generator, and further including clock generator circuit means for supplying clock pulses to said multiplex generator and to said shift register circuit for advancing the same in synchronism with one another.
- 4. The combination according to claim 3, further including means coupled with the output of said coincidence gate means for producing tones corresponding to the respective notes represented by the pulses at the output of said coincidence gate means for a duration proportional to the number of times each such pulse appears in corresponding time slots of consecutive sequences of time slots in said multiplex signal at the output of said coincidence gate means.
- 5. The combination according to claim 2, wherein said inverter circuit means is in said second signal channel and said coincidence gate means comprises a NAND gate, a pulse in a time slot indicative of the actuation of a switch comprises a negative data pulse, said shift register circuit normally producing a positive output in the absence of the application to the input thereof of a negative data pulse, so that said NAND gate produces a negative pulse at its output only when the output of said shift register is positive and the output of said inverter circuit means is simultaneously positive.
Parent Case Info
This is a continuation of application Ser. No. 562,174 filed on Mar. 26, 1975, and now abandoned.
US Referenced Citations (3)
Continuations (1)
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Number |
Date |
Country |
Parent |
562174 |
Mar 1975 |
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