Norlin Industries, Inc.

David T Starkey

William Wangard

A tone generator for an electronic musical instrument is operable for producing a highly stable tone signal over an extended frequency range. The tone generator comprises a timing circuit defining first and second time intervals occurring in respective time succession after the occurrence of a transition of an input signal. A timing capacitor is charged during each second time interval and discharged during the time intervals occurring between the end and beginning of successive ones of the second time intervals. A feedback circuit is enabled during each of the first time intervals for coupling the timing capacitor for controlling the discharge rate so that a highly stable ramp output tone signal is produced.

Frequency independent ramp generator

An electronic organ having a scanned keyboard manual (10) includes a keyboard latch (24) interposed between the scanning apparatus (12) and the organ keyers (26). The keyboard latch (24) comprises a gate (42) for comparing the serial data pulses, each of which represents a respective depressed key, produced at the output of the scanning apparatus (12) during each scan of the keyboard manual (10) with the serial data pulses produced during the immediately preceding scan for developing a control signal representing the detection of a depressed keyboard key during the on-going scan which was not depressed during the immediately preceding scan. An output circuit (52, 54, 56) is provided for continuously developing an output signal reflecting the keys depressed during the last scan in which a control signal was developed whereby the tone signals corresponding thereto are continuously sounded even though the keys have subsequently been released.

Keyboard latch for electronic organ

A circuit for generating alternating repeat keying signals in an electronic keyboard musical instrument includes a clock, a logic circuit responsive to the keys of the instrument and to the clock for producing an alternating sequence of logic signals corresponding to each of the keys, the phase of the sequence corresponding to each undepressed key being the same as the phase of the sequence corresponding to the previous key and the phase of the sequence corresponding to each depressed key being opposite that of the phase of the sequence corresponding to the previous key and a plurality of output gates each developing a keying signal in response to the depression of a respective one of the keys and the logic signals of the corresponding sequence assuming a predetermined state.

Alternating repeat keying signal generator

A data encoder for use with a time multiplexed electronic organ or the like comprises a multiple stage shift register, means for simultaneously loading a predetermined pattern of logic bits in the shift register in response to a key down representative data pulse and means for coupling the output of the shift register to one of the data channels of the organ. In a first mode, the data encoder is operable as a fill-note generator wherein the shift register is loaded in response to an upper manual key down representative data pulse and lower manual key down representative data pulses are coupled to the upper manual data channel of the organ according to the output of the shift register. In a second mode, the data encoder is operable as a chimes generator wherein the shift register is loaded in response to an upper manual key down representative data pulse and the output of the shift register is coupled to the upper manual data channel of the organ. In a final mode, the data encoder is operable as a chord function generator wherein the shift register is loaded in response to a lower manual key down representative data pulse and the output of the shift register is coupled to the lower manual data channel of the organ.

Growing community of inventors

Oak Park, IL, United States of America

David T Starkey