Electric organ tone generating system

Apparatus for generating a multiplicity of tones as required in an electronic organ comprising

• a. a plurality of free running tone oscillators for producing each of said required tones, each of said tone oscillators including means for controlling the frequency thereof in response to a stored control voltage, means for altering said control voltage in response to a CORRECT pulse present on a CORRECT bus, a gate coupling said CORRECT bus to said control voltage altering means, a select input coupled to said gate for enabling said gate to pass pulses from said CORRECT bus to said control voltage altering means, a second gate coupled to said select input for enabling pulses from said tone oscillator to appear on a READ bus,
• b. means for sequentially selecting each of said tone oscillators, including a source of auxilliary clock pulses, a binary counter, means coupling said clock pulses to said counter to increment said counter, means for decoding the content of said counter into a plurality of select lines, means coupling each of said select line to one of said tone oscillators via its select input,
• c. logic means coupled to said selection means and to said CORRECT and READ bus including a frequency comparator, means coupling said comparator to said READ bus, storage means for storing a representation of each desired tone oscillator frequency, means coupled to said storage means for selecting said representation corresponding to said selected tone oscillator, means coupled to said frequency comparator for generating said CORRECT pulse in response to the difference between the frequency of said selected tone oscillator and said representation selected from said storage means, means coupling said CORRECT pulse generating means to said CORRECT bus.