Abstract: A method of manufacturing a circuit board from a copper clad board comprises the steps of designing a circuit configuration of the circuit board on a computer-aided design system and then determining a desired circuit configuration outline on the computer-aided design system from the circuit configuration. The desired circuit configuration outline is provided to a computer-aided machining system which controls a laser, milling machine and the like to remove conductive material along the outline, leaving conductive material formed adjacent the removed material as the circuit configuration.

Abstract: A test system for functionally testing and troubleshooting microprocessor-based systems and assemblies is disclosed wherein the test system is connected in place of the microprocessor circuit of the unit being tested (UUT). The test system is itself a microprocessor-based system and includes a microprocessor circuit which is supplied with the UUT clock signal and is the same type of microprocessor circuit as is utilized by the UUT. The test system periodically switches this microprocessor into signal communication with the UUT for a single UUT bus cycle to perform UUT read or write operations. During remaining time periods, the test system microprocessor circuit is in signal communication with the remaining portion of the test system to analyze data obtained from the UUT bus during the previous UUT write or read operation and to establish the signals to be used in the next UUT write or read operation. Various test sequences are provided for testing the UUT bus, RAM, ROM, and write-responsive I/O registers.

Abstract: An electronic organ includes logic and a memory for detecting and storing a root note signal identifying a chord which has been either automatically or manually generated. Priority logic, coupled with the memory, passes the lowest root note signal to a tone selection matrix which passes a plurality of tone signals representing the note intervals forming the selected chord. A sequential gating circuit receives all of the tone signals and is responsive to an arpeggio circuit, a strum circuit, or a rhythm unit to gate selected tone signals, one at a time, to the voicing circuitry. When one or more of the tone signals are octavely displaced within the selected chord, disinverting gates are enabled to unfold the chord and cause the tone signals to occur in order of ascending frequency.

Abstract: An electronic organ includes logic and a memory for detecting and storing a root note signal identifying a chord which has been either automatically or manually generated. Priority logic, coupled with the memory, passes the lowest root note signal to a tone selection matrix which passes a plurality of tone signals representing the note intervals forming the selected chord. A sequential gating circuit receives all of the tone signals and is responsive to an arpeggio circuit, a strum circuit, or a rhythm unit to gate selected tone signals, one at a time, to the voicing circuitry. When one or more of the tone signals are octavely displaced within the selected chord, disinverting gates are enabled to unfold the chord and cause the tone signals to occur in order of ascending frequency.

Abstract: An electronic musical synthesizer generates tone signals coupled to a controllable bandpass filter and a controllable low-pass filter. A plurality of voice switches are individually selectable to couple preset control voltages to the filters, and to enable potentiometers which can be adjusted to generate control voltages to vary the frequency characteristics of the filters, control the octave of the tone signals, and to control a modulation oscillator. When a variable/preset switch is set to a preset state, the potentiometers are disconnected and auxiliary sections of the selected voice switch presets voltages for the oscillator, the octave circuit and the filters.