Abstract: An interface system for expanding the number of device input ports and compatable with the message format and bus structure of a standard interface, namely the IEEE standard 488, has address decoding logic which identifies the expansion system and is operative to select, in accordance with an incoming message on the bus, which of several ports is to transmit or receive messages via the bus. Under control of the port identification message and strobe signals obtained from the handshake control logic of the expansion system, a sequence containing a predetermined number of bytes of port data is transmitted to the bus. The port data bytes may be coded in various formats, desirably BCD, which is compatable with the digital output format of many devices which may be interconnected and interfaced by the expansion system with the bus.

Abstract: An automatic chord control system is readily incorporated in an electronic organ by means of large scale integrated circuit chips. The automatic chord control causes a chord or group of notes within an octave played on the lower manual keyboard to play through the upper manual voice in the octave below the lowest melody note being played on the upper manual keyboard. The proposed automatic chord control system has two operating modes. In the first mode, the notes transferred to the upper manual are generated in direct correspondence to the keys activated on the lower manual. In the second mode, the notes transferred to the upper manual are generated by a set of preset chords activated by single lower manual keys.

Abstract: Weighted modulus numbering apparatus is capable of printing composite numbers consisting of serial identification numbers and accompanying check digits which are determined in accordance with a system where the check digits for certain identification numbers may be invalid, as by requiring a two-digit number rather than an allowable single-digit number. The check digits are generated in the form of digital (for example, binary) words and decoded to provide a signal representing the validity or invalidity of the check digit. A memory stores the check digit words and a bit representing the validity/invalidity of the check digit. The decoding of an invalid check digit operates to cause the word representing the check digit for the next successive identification number to be stored with the valid/invalid bit in memory. The numbering machine, which presents the successive identification numbers for printing, is caused to increment twice in response to a signal representing an invalid check digit.

Abstract: Process requirements, such as high speed operations, make it necessary that a multiplicity of devices be controlled such that they perform different operations at the same time which, however, have the same effect as if the same operation is performed by all of the multiplicity of devices simultaneously. In high speed operations, for example, the printing of identification numbers and corresponding check digits, the same material must be printed in many places on each document but with printers capable only of printing each identification number of a different document at the same time as the documents are fed at high speed through the imprinting machine. A control system is described which assembles digital data representing the operations to be performed by the devices (the printed material consisting of the digits corresponding to the identification numbers which are presented by numbering machines which are incremented as the imprinter executes its successive document feeding cycles).

Abstract: An accompaniment system for an electronic musical instrument is selectively actuatable for producing accompaniment effects such as arpeggio in accordance with selectable notes or chords and with selectable rhythm patterns. The electronic musical instrument includes one or more conventional keyboards, a set of chord switches for selecting one of a plurality of predetermined chords and a set of rhythm switches for selecting one of a plurality of predetermined rhythm patterns, respectively. The accompaniment system includes a ROM containing note position signals arranged in a plurality of groups, each group corresponding to one of the selectable rhythm patterns. An electronic circuit selects one of the groups in response to activation of one of the rhythm pattern selector switches and sequentially combines each note position signal in the group with a chord displacement signal developed in response to actuation of one of the keyboard notes or chord selection switches.

Abstract: A binary interpolator circuit is embodied in an electronic musical instrument for producing a relatively smooth, inaudible transition between steps of different amplitude in a stepwise advancing or decreasing waveform, such as an envelope signal for a note from a percussive type instrument or voice such as a piano. The binary interpolator circuit includes a counter circuit for producing a sequence of stepwise changing binary coded signals and a combining circuit for combining the interpolating signals, in the sequence produced, with a binary coded scaling signal corresponding to the amplitude difference between the two points in the stepwise changing waveform between which interpolation is desired. A comparator circuit compares the interpolating signals, in the sequence produced, with the scaling signal and produces an output control signal for indicating whether the binary coded numbers corresponding to the respective interpolating and scaling signal are equal.

Abstract: An electronic musical instrument develops digital pulses corresponding to electronic waves that are subsequently converted to audio sound such as by means of a loudspeaker. The musical instrument is provided a source of master frequency generated binary related numbers which act in conjunction with a read only memory, an adder, and a comparator, and also a counter, to control a J/K flip-flop to produce a pulse train output in which for any given cycle the starting time and duration of each pulse is controlled, thereby to determine the harmonic content of the electronic waves that are converted to audio sound.

Abstract: A control system is described which assembles digital data representing the operations to be performed by the devices (the printed material consisting of the digits corresponding to the identification numbers which are presented by numbering machines which are incremented as the imprinter executes its successive document feeding cycles). A channel is provided for each device, which is responsive to the data and through which the data is advanced so as to operate the device in accordance therewith. A check digit printing device is operated by way of its associated channels so as to present the check digit corresponding to the identification number to be printed and enable corresponding identification numbers and check digits to be printed simultaneously at different locations on a multiplicity of different documents.

Abstract: An automatic chord control system is readily incorporated in an electronic organ by means of large scale integrated circuit chips. The automatic chord control causes a chord or group of notes within an octave played on the lower manual keyboard to play through the upper manual voice in the octave below the lowest melody note being played on the upper manual keyboard. The proposed automatic chord control system has two operating modes. In the first mode, the notes transferred to the upper manual are generated in direct correspondence to the keys activated on the lower manual. In the second mode, the notes transferred to the upper manual are generated by a set of preset chords activated by single lower manual keys.

Abstract: A programmable rhythm unit is disclosed for electrically simulating sounds of a plurality of rhythm instruments being played in selected ones of a plurality of different rhythmic patterns. A variable frequency oscillator cooperates with a counter/divider and decoder circuit to provide a predetermined number of beats or pulses per measure at a tempo which may be varied by the user. Also provided is a plurality of keyed audio circuits which each produce a characteristic burst of output signals that simulate the audible output or voice of a corresponding rhythm instrument. Switching means are provided whereby the user can select any of the voices to play at any beat position. In addition an alternate beat pulse source is provided which can be selected by the switching means to play any of the voices at a particular beat position every other measure. A pseudo-random generator is also included which may be selected to play any of the voices at a random beat position in each measure.

Abstract: A LSI (large scale integrated circuit) device is disclosed which generates 12 output frequencies related to each other by a multiple of the twelfth root of two from a common time base without the use of parallel divider or shift register strings. The output frequencies comprise the top octave, or a multiple thereof, of the frequencies of an electronic musical instrument. A binary counter serves as a common time base and encodes each wave form period in a form of a binary code. A binary processing circuit associated with each output frequency stores the count position of the next desired wave form transition and updates the stored code after each transition has occurred. The binary processing circuitry comprises a latch circuit, a binary full adder or ROM (read only memory), a digital comparator or ROM, and a J-K flip-flop circuit. The outputs can be easily modified in both actual frequency and waveform symmetry.

Abstract: A tone-generating system for an electronic musical instrument of the percussion type is provided wherein an audible tone closely approximating the corresponding tone of a conventional instrument is generated electronically. A single-pole, double-throw switch is actuated by a key to initiate generation of the tone and a tri-level detecting circuit coupled to the switch is utilized to determine which of the three states the switch is in; that is, the two "throws" or positions of the switch which correspond to the released and depressed positions of the key, and the state in which the switch is between the other two positions. By detecting the three states and developing corresponding control signals, counting circuitry may be utilized to determine the intensity with which the key is depressed to enable generation by a read-only memory of digital scaling signals representative of the variations in amplitude of the initiated tone with respect to the intensity with which the key is depressed.

Abstract: The embodiment of the invention disclosed herein is directed to an electronic phonograph selector and memory system which enables the selection of records to be played after the proper amount of credits have been accumulated in a coin accumulating circuit. The system has a movable record carriage for placing a desired one of a plurality of records at a playing location. The record carriage is transported by receiving a drive signal indicating that a new carriage position is required. The code signal information is compared so that when the carriage is at its desired location the search signal is removed. The movable carriage has a position encoder so that binary code signal information corresponding to the various positions of the carriage can be detected and compared to the codes stored in a random access memory circuit.