US3743755A - Method and apparatus for addressing a memory at selectively controlled rates - Google Patents
Method and apparatus for addressing a memory at selectively controlled rates Download PDFInfo
- Publication number
- US3743755A US3743755A US00170992A US3743755DA US3743755A US 3743755 A US3743755 A US 3743755A US 00170992 A US00170992 A US 00170992A US 3743755D A US3743755D A US 3743755DA US 3743755 A US3743755 A US 3743755A
- Authority
- US
- United States
- Prior art keywords
- note
- memory
- frequency
- waveform
- rate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Classifications
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10H—ELECTROPHONIC MUSICAL INSTRUMENTS; INSTRUMENTS IN WHICH THE TONES ARE GENERATED BY ELECTROMECHANICAL MEANS OR ELECTRONIC GENERATORS, OR IN WHICH THE TONES ARE SYNTHESISED FROM A DATA STORE
- G10H7/00—Instruments in which the tones are synthesised from a data store, e.g. computer organs
- G10H7/02—Instruments in which the tones are synthesised from a data store, e.g. computer organs in which amplitudes at successive sample points of a tone waveform are stored in one or more memories
- G10H7/04—Instruments in which the tones are synthesised from a data store, e.g. computer organs in which amplitudes at successive sample points of a tone waveform are stored in one or more memories in which amplitudes are read at varying rates, e.g. according to pitch
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F1/00—Details not covered by groups G06F3/00 - G06F13/00 and G06F21/00
- G06F1/02—Digital function generators
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F1/00—Details not covered by groups G06F3/00 - G06F13/00 and G06F21/00
- G06F1/02—Digital function generators
- G06F1/03—Digital function generators working, at least partly, by table look-up
- G06F1/0321—Waveform generators, i.e. devices for generating periodical functions of time, e.g. direct digital synthesizers
- G06F1/0328—Waveform generators, i.e. devices for generating periodical functions of time, e.g. direct digital synthesizers in which the phase increment is adjustable, e.g. by using an adder-accumulator
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10H—ELECTROPHONIC MUSICAL INSTRUMENTS; INSTRUMENTS IN WHICH THE TONES ARE GENERATED BY ELECTROMECHANICAL MEANS OR ELECTRONIC GENERATORS, OR IN WHICH THE TONES ARE SYNTHESISED FROM A DATA STORE
- G10H1/00—Details of electrophonic musical instruments
- G10H1/02—Means for controlling the tone frequencies, e.g. attack or decay; Means for producing special musical effects, e.g. vibratos or glissandos
- G10H1/04—Means for controlling the tone frequencies, e.g. attack or decay; Means for producing special musical effects, e.g. vibratos or glissandos by additional modulation
- G10H1/053—Means for controlling the tone frequencies, e.g. attack or decay; Means for producing special musical effects, e.g. vibratos or glissandos by additional modulation during execution only
- G10H1/057—Means for controlling the tone frequencies, e.g. attack or decay; Means for producing special musical effects, e.g. vibratos or glissandos by additional modulation during execution only by envelope-forming circuits
- G10H1/0575—Means for controlling the tone frequencies, e.g. attack or decay; Means for producing special musical effects, e.g. vibratos or glissandos by additional modulation during execution only by envelope-forming circuits using a data store from which the envelope is synthesized
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10H—ELECTROPHONIC MUSICAL INSTRUMENTS; INSTRUMENTS IN WHICH THE TONES ARE GENERATED BY ELECTROMECHANICAL MEANS OR ELECTRONIC GENERATORS, OR IN WHICH THE TONES ARE SYNTHESISED FROM A DATA STORE
- G10H1/00—Details of electrophonic musical instruments
- G10H1/18—Selecting circuits
- G10H1/182—Key multiplexing
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10H—ELECTROPHONIC MUSICAL INSTRUMENTS; INSTRUMENTS IN WHICH THE TONES ARE GENERATED BY ELECTROMECHANICAL MEANS OR ELECTRONIC GENERATORS, OR IN WHICH THE TONES ARE SYNTHESISED FROM A DATA STORE
- G10H1/00—Details of electrophonic musical instruments
- G10H1/18—Selecting circuits
- G10H1/20—Selecting circuits for transposition
Definitions
- a memory contains digital data of related informational content in a plurality of discrete locations identified by respective addresses.
- the memory is addressed, or accessed, at a rate which depends upon the desired spacing between data from the various locations as it is sequentially read from the memory.
- the data constitutes amplitude values of a complex waveform of the type produced by a musical instrument, at equally spaced points in time along an axis of the waveform.
- Apparatus for addressing the memory at any of a plurality of selectively controlled rates includes a calculator for continuously computing a set of numbers each defining a different spacing between the data during readout of the memory.
- a desired rate of readout is selected, as by selecting a desired frequency of repetition of a complete cycle of the stored waveform, the number associated with that rate is sampled from the computed set and is periodically increased by its own value to identify appropriate data addresses in the memory, for accessing that data, at intervals of the periodic increase corresponding to the desired rate of readout.
- the data may, for example, consist of digital samples of the amplitude of a waveform at successive selected points, or may consist of a list of symbols identifying in a particular order the members of a class of prescribed characteristics, or may consist of a mathematical progression of numbers, or may consist of other information.
- the rate at which the samples are read from the memory can be used to determlne the frequency of the output waveform, or the phase angle of the waveform relative to a fixed reference.
- the frequency of the output waveform may be varied by changing the rate at which the address changes. In the latter case, the same data may be read from the memory several times in succession where the address is unchanged through several access commands, so that the same memory location is addressed each time. For certain types of stored data, no difficulty may be encountered with such a process.
- the invention includes means for performing a calculation to derive a number that determines the rate at which the memory shall be accessed, regardless of the consistency of the clock rate at which the overall system is operated.
- the calculating means continuously calculates a'set of distinct and different numbers, and means are provided to select a desired number that will produce a predetermined rate ofaccessing of the memory based on the occurrence of a related oneof a set of selected events. Thus, if an event occurs, the number with which that event is associated is selected and determines the rate at which the memory is accessed. Evey number is periodically calculated in cyclic sequence to ensure its availability when the event with which it is associated occurs. I
- a memory unit in a digital electronic musical instrument is addressed at a rate which is selectively controllable according to the frequency (or phase angle relative to a reference phase) of the note to be produced by the instrument.
- the memory unit contains digital data representing samples of the amplitude of a complex waveform at a plurality of uniformly spaced points in time (i.e., along the abscissa, or time axis, of the waveform).
- the complex waveform is identical for each note, but its rate of cyclic repetition is to be varied according to the frequency of the note to be played.
- the individual amplitude samples are stored in separate locations, preferably at sequential addresses although this is not absolutely necessary, of a read-only memory (ROM), and the memory is thereafter addressed, i.e., the stored data is accessed or read out, at a rate which depends upon the frequency of the note to be generated by the instrument.
- ROM read-only memory
- the instrument has a plurality of keyboards, including at least one manual and at least one pedal division. Each keyboard may cover several octaves.
- a key is depressed on any keyboard of the digital electronic organ, a sound waveform is to be generated with a periodicity corresponding to the desired note frequency.
- the waveform is computed in digital format consisting of a series of digital words which represent the magnitude of the waveform at a series, or sequence, of uniformly spaced sample points. The digital sample point values thus generated are subsequently converted to analog form.
- the sample points are preferably uniformly spaced because such a format permits the most direct analysis, and therefore the most direct synthesis, of the desired waveform.
- the uniform spacing of sample points may be such that there is provided an integral number of samples per cycle for each note frequency to be generated. Such a technique requires a sampling rate that varies directly with the frequency.
- the samples may be spaced uniformly in time, in which case the number of sample points differs according to frequency, and the phase angle between sample points varies with the frequency of the note to be generated.
- the preferred frequency synthesis technique is that in which the phase angle between the sample points varies with frequency, i.e., in which the sampling rate is fixed for all note frequencies to be generated, and the various generated note frequencies are produced as a result of the different phase angles.
- the selection of a particular phase angle is translated into a sample point address in the memory unit within which the digital values representing amplitude samples of the waveform are stored.
- the rate at which the memory unit is addressed changes. This is accomplished by providing an address register to which the phase angle number is supplied, and which is incremented according to the value of the phase angle number. That is to say, once each clock time, the phase angle number is added to the sample point address register. Only a relatively small number of bits of rather low significance in the latter register are used to designate the sample point addresses, and these bits are arranged to be incremented at a rate which depends upon the phase angle number, so that a new address may or may not be specified for several periodic increases in the address-identifying word. In the limit, an actual sample point address in the memory is identified and the memory is thereupon appropriately accessed for retrieval of the data contained at those addresses, for each increment dictated by the phase angle number. This limit is the uppermost note frequency that can be generated by the organ. For lower frequencies, the incrementing of the sample point address register is such that new addresses are identified only after a corresponding number of repetitions of the phase angle number, at the fixed clock frequency.
- Still another object of this invention is to provide a method and apparatus as set forth above, specifically for use in the tone generating system of a digital electronic musical instrument.
- FIG. I is a simplified block diagram of a portion of a digital electronic organ system whose overall structure and function demonstrates a specific application of the controllable readout of a memory in accordance with the invention, in which portion a time division multiplexed signal is produced containing a recycling sequence of time slots each associated with a particular key of the organ, the contents of each time slot indicating whether the associated key has been actuated;
- FIG. 2 is a circuit diagram of an exemplary decoder for use in the system of FIG. I;
- FIG. 3 is a more detailed circuit diagram of the switching array and encoder used in the system of FIG.
- FIG. 3A is a circuit diagram of an alternative encoder to that shown in FIG. 3, for use in the system of FIG,
- FIG. 4 is a circuit diagram of the input-output bus connecting means at each intersection in the switching array of FIG. 3;
- FIG. 5 is illustrative of a multiplexed waveform developed by the system of FIG. 1 and responsive to actuation of selected keys;
- FIG. 6 is a simplified block diagram of a generator assignment and tone generating apparatus for processing the multiplexed signal produced by the system of FIG. I to develop the desired tones as an audible output of the organ;
- FIG. 7A and 7B together constitute a circuit diagram of one embodiment of the tone generator assignment logic for the system of FIG. 6;
- FIG. 8A is a block diagram of a tone generator employing the principles of the present invention with regard to selective rate of addressing a memory, for use with assignment logic of FIGS. 7A and 7B in the system of FIG. 6;
- FIG. 8B is a block diagram of an alternate embodiment of a portion of the tone generator of FIG. 8A.
- FIG. 9 is illustrative of a complex waveshape of the type produced by a pipe organ, and of the sample points at which amplitude values are taken for simulation at selected note frequencies.
- the keyboard multiplexing system or note selection system includes a keyboard counter l which is implemented to provide a specified count for each key of each keyboard (including manuals and pedal divisions) of the organ. If, for example, the electronic organ in which the multiplexing system is used has four keyboards, such as three manuals and a pedal board, each encompassing up to eight octaves, then keyboard counter 1 should have the capability of generating 4 X 8 X 12 384 separate counts (digital words).
- the counter be capable of developing a count representative of every key on every keyboard of the organ; however, it may be desirable to provide a counter that can produce a count greater than the number of available keys in order to have available certain redundant counts not associated with any keys. Such redundancy is readily provided by simply utilizing a counter of greater capacity than the minimum required count.
- Keyboard counter 1 is divided into three separate sections (or separate counters) designated 2, 3 and 4.
- the first section (designated 2) is constructed to count modulo 12 so as to designate each of the twelve keys associated with the 12 notes in any octave.
- the second section (designated 3) is adapted to count modulo 8, to specify each of the eight octaves encompassed by any of the four keyboards.
- the last section (designated 4) is designed to count modulo 4 to specify each keyboard of the organ. Therefore, the overall keyboard counter is arranged to count modulo 384, in that at the conclusion of every 384 counts, the entire set of keyboards have been covered (scanned) and the count repeats itself.
- each counter section may be composed of a separate conventional ring counter, the three counters being connected in the typical cascaded configuration such that when section 2 reaches its maximum count it advances the court of counter section 3 by one, and will automatically initiate a repetition of its own count. Similarly, attainment of its maximum count by counter section 3 is accompanied by advancement of the count of section 4 by one.
- Advancement of the count of counter 2 is accomplished by application of clock pulses thereto from a master clock source 5 which delivers clock pulses at a sufficiently rapid repetition rate (frequency) to ensure resolution of depression (actuation) and release (deactuation) of any key on any keyboard, i.e., to supply a pulse at the instant of either of these events. Scanning of all keyboards of the organ at a rate of 200 or more times a second is deemed quite adequate to obtain this desirable resolution. For the exemplary keyboard counter set forth above, this is equivalent to a minimum of 200 X 384 76,800 counts per second, so that a master clock delivering clock pulses at a rate of 100 KC/s is quite suitable.
- a total of four lines emanate from counter 4, one line connected to each ring counter stage, to permit sensing of the specific keyboard which is presently being scanned.
- eight lines are connected to the eight ring counter stages, respectively, of octave counter 3 to detect the octave presently being scanned.
- a total of 12 lines extend from counters 3 and 4, and these twelve lines can carry signals indicative of 32 (8 X 4) possible states of the keyboard counter.
- the specific one of the 32 states, representative of a particular octave on a particular keyboard, which is presently being scanned is determined by use of a decoder circuit 7 composed of 32 AND gates designated 8-1, 8 2, 8-3, 8-32 (FIG. 2), each with two input terminals and an output terminal.
- the gates are arranged in four groups of eight each, with every gate of a particular group having one of its two input terminals (ports) connected to one of the four lines of counter 4. Distinct and different ones of the eight lines from counter 3 are connected to the other input terminal of respective ones of the eight AND gates of that group.
- each group of AND gates designates every octave of keys in the organ by a respective driver pulse when a count corresponding to that octave is presently contained in the counter.
- the output pulses derived from the AND gates (or drivers) of decoder circuit 7 are supplied on respective ones of 32 bus bars (or simply, buses), generally designated by reference numeral 10, to a keyboard switching array ll. From the preceding descripton, then, it will be clear that array 11 has one input bus 10 for every octave of keys in the organ (including every octave on every keyboard), and that a drive pulse will appear on each input bus approximately 200 times per second, the exemplary rate of scan of the keyboard, as noted above, for obtaining adequate resolution of operation of the keys. Switching array 11 also has twelve output buses, generally designated by reference number 12, each to be associated with a respective one of the twelve notes (and hence, the twelve keys) in any given octave.
- Array llli is basically a diode switching matrix, in which spaced input buses It) and spaced output buses 12 are orthogonally arranged so that an intersection or crossing occurs between each input bus and each output bus (see FIG. 3), for a total of 384 intersections, one for each count of the keyboard counter 1.
- the crossed lines or buses are not directly interconnected. Instead, a jump diode, such as that designated by reference number 113 in FIG. 4, is connected between the input bus 10 and the output bus 12 at each intersection, the diode poled for forward conduction (anode-to-cathode) in the direction from an input bus 10 to an output bus 12.
- each diode 13 Wired in series circuit or series connection with each diode 13 is a respective switch 14 which is normally open circuited and is associated with a distinct respective one of the keys of the organ, such that depression of the associated key produces closure (close circuiting) of the switch 14 whereas release of the associated key results in return of the switch to its open state.
- a respective switch 14 which is normally open circuited and is associated with a distinct respective one of the keys of the organ, such that depression of the associated key produces closure (close circuiting) of the switch 14 whereas release of the associated key results in return of the switch to its open state.
- each of switches 14 may itself constitute a respective key of the various keyboards of the organ.
- switch 14 is shown schematically as being of mechanical single pole, single throw (SPST) structure, it will be understood that any form of switch, electronic, electromechanical, electromagnetic, and so forth, may be utilized, the exact nature of the switch depending primarily upon the nature of the energization produced upon operation of the associated key.
- Switch 14, then, is adapted to respond to the particular form of enerization or actuation produced upon operation of a key on any keyboard (or, as observed above, may itself constitute the key), to complete the circuit connecting associated diode 13 between a respective input bus 10 and a respective output bus 12 at the intersection of those buses, when the key is depressed, and to open the circuit connecting the diode between respective input and output buses at that intersection when the key is released.
- SPST mechanical single pole, single throw
- the output buses 12 from switching array 11 are connected to an encoder circuit 15 to which are also connected the twelve output lines, generally designated by reference number 16, from keyboard counter section 2.
- the switches 14 associated with the respective keys are conveniently arranged in a specific sequence in the switching array 11. Assume, for example, that a specific output bus 17 of the switching array is to be associated with note A of any octave, a second output bus 18 is to be associated with note B of any octave, and so forth.
- switches 14 in the row corresponding to output bus 17 in array or matrix 11 are associated with the keys corresponding to the note A in each octave of keys in the organ.
- the column position of each switch 14 in matrix I 1 corresponds to a specific octave of keys in the organ, and hence, to a specific octave encompassed by a specific keyboard of the organ.
- Each of the output buses 12, including l7, l8, and so forth, is connected to one of the two input ports or terminals of a respective AND gate of the twelve AND gates 20-1, 20-2, 20-3, 20-12, of encoder circuit 15.
- An output lead 16 of counter section 2 associated with the ring counter stage designating the count for a particular note (key) in a given octave is connected to the remaining port of an encoder circuit AND gate having as its other input a pulse on the output bus 12 associated with that same note.
- a similar arrangement is provided for each of the remaining eleven output lines 16 of counter section 2 with respect to the AND gates 20 and the output buses 12.
- encoder circuit is effective to convert the parallel output of array 11 to a serial output signal in accordance with the scanning of output buses 12 as provided by the advancing and repeating count sensed in the form of pulses (at a-rate of about 200 per second) appearing on output lines 16.
- the end result of this circuitry is the production of a time-division multiplex (TDM) signal on a single conductor 25 emanating from encoder 15.
- TDM time-division multiplex
- the encoder may have the circuit configuration exemplified by FIG. 3A.
- the encoder includes a shift register 80 having twelve cascaded stages designated SR1, SR2, SR3, SR12, each connected to a respective output bus 12 of switching matrix 11 to receive a respective output pulse appearing thereon.
- the shift register stages are loaded in parallel with the data read from switching array 11 on output buses 12, in response to each of the pulses appearing (i.e., each time a pulse appears) on one of the 12 output leads 16 of note counter 2.
- That one output of the note counter which is to supply the load command for all twelve stages of shift register 80 is selected to permit the maximum amount of settling time to elapse between each advance of octave counter 3 and keyboard counter 4 and the loading of the shift register.
- the first note counter stage or one of the early stages, is selected to provide load pulses to shift register 80.
- Shift pulses are supplied to the shift register by master clock 5, which also supplies note counter 2, to shift the contents of each shift register stage to the next succeeding stage except during those bit times when the shift pulse is pre-empted by a load pulse from the note counter. Accordingly, shift register 80 is parallel loaded, and the data contents of the register are then shifted out of the register in serial format on encoder output line 25 until a one-bit pause occurs when another set of data is parallel loaded into the shift register, followed again by serial readout on line 25.
- This serial pulse train constitutes the time division multiplexed output signal of encoder 15 just as in the embodiment of FIG. 3, except that with the FIG. 3A configuration, decoder 7 (and the counters 3 and 4 supplying pulses thereto) undergo a greater amount of settling time.
- each key has a designated time slot in the 384 time slots constituting one complete scan of every keyboard of the organ.
- the TDM waveform (shown by way of example in FIG. 5) is initiated about 200 times per second.
- This waveform contains all of the note selection information, in serial digital form on a single output line, that had heretofore required complex wiring arrangements.
- This waveform development will be more clearly understood from an example of the operation of the circuitry thus far discussed. It should be observed first, however, that all of the counter and logic circuitry described up to this point can be accommodated within a very small volume of space by fabrication in integrated circuit form using conventional microelectronic manufacturing techniques.
- C appears in the appropriate time slot of the multiplexed signal emanating from encoder and will repetitively appear in that time slot in each scan of the keyboards of the organ as long as that key is depressed. That is to say, a pulse appears on output line 10 of decoder 7 associated with the second octave in the manual being played, in accordance with the scan provided by master clock 5, as the counter stage associated with that octave is energized in keyboard counter octave section 3 and the counter stage associated with that manual is energized in section 4 of the keyboard counter.
- connection between the appropriate input bus 10 and output bus 12 of switching array 11 for the particular octave and keyboard under consideration is effected by the depression and continued operation of the key associated with the switch 14 for that intersection in the array. Since, as previously stated, each switch is associated with a particular note (key) and is positioned in a specific row of the switching array, a signal level is thereby supplied to the appropriate output bus 12 of the switching array arranged to be associated with that note.
- a second input is provided to the AND gate 20 receiving the signal level on output bus 12, and a pulse is delivered to OR gate 23.
- the pulse which appears at the output of OR gate 23 always appears in the identical specified time slot in the multiplexed signal for a specific note associated with a particular key on a particular keyboard of the organ.
- FIG. 5 An example of the multiplex signal waveform thus generated is shown in FIG. 5. While the pulses appearing in the time slots associated with the specific notes mentioned above are in a serial format or sequential order, their appearance is repetitive during the interval in which the respective keys are actuated. Hence, the effect is to produce a simultaneous reproduction of the notes as an audio output of the organ, as will be explained in more detail in connection with the description of operation of the tone generation section.
- the multiplexed signal arriving from encoder 15 is supplied to generator assignment logic network 26 which functions to assign a tone generator 28 to a depressed key (and hence, to generate a particular note) when the associated pulse first appears in its respective time slot in the multiplexed signal supplied to the assignment logic.
- generator assignment logic network 26 which functions to assign a tone generator 28 to a depressed key (and hence, to generate a particular note) when the associated pulse first appears in its respective time slot in the multiplexed signal supplied to the assignment logic. If only 12 tone generators 28 are available in the particular organ under consideration, for example, the assignments are to be effected in sequence (order of availability), and once particular pulses have been directed to all of the available generators (i.e., all available tone generators have been captured by respective note assignments), the organ is in a state of saturation. Therafter, no further assignments can be made until one or more of the tone generators ls released.
- the availability of 12 (or more) tone generators renders it extremely unlikely that the organ would ever reach a state of saturation since it is quite improbable that more than twelve keys would be depressed in any given instant of time during performance of a musical selection.
- the output waveforms from the captured tone generators at the proper frequencies for the notes being played are supplied as outputs to appropriate waveshaping and amplification networks and thence to the acoustical output speakers of the organ. If the tone generators 28 supply a digital representation of the desired waveform, as is the case in one embodiment to be described, then the digital format is supplied to an appropriate digitalto-analog converter, which in turn supplies an output to the waveshaping network.
- each tone generator 28 may be in only one of three possible states, although the concurrent states of the tone generators may differ from one tone generator to the next. These three states are as follows:
- the tone generator is presently uncaptured (i.e., unclaimed or available), but wlll be captured by the next incoming pulse in the multiplexed signal associated with a note which is not presently a tone generator captor;
- the tone generator is presently available, and will not be captured by the next incoming pulse.
- any number of the tone generators provided (12, in this particular example) may be in one or the other of the states designated (1) and (3), above, but that only one of the tone generators can be in state (2) during a given instant of time. That is, one and only one generator is the next generator to be claimed.
- the specific tone generator in state (2) is claimed by an incoming pulse
- the next incoming pulse which is not presently claiming a tone generator is to be assigned to the generator that has now assumed state (2). For example, if the third tone generator (No. 3) of the 12 generators is captured by an incoming pulse (note representation) and the fourth generator (No. 4) was and still is captured by a previous note selection, then tone generator No.
- Generator assignment system 26 is utilized to implement the logic leading to the desired assignment of the tone generators 28, and thus to the three states of operation described above. An exemplary embodiment of the generator assignment logic is shown in FIGS. 7A and 78. Referring to FIG.
- a ring counter 30, or a 12-bit recirculating shift register in which one and only one bit position is a logical l at any one time, is used to introduce a claim selection, i.e., to initiate the capture, of the next available tone generator in the set of tone generators 28 provided in the organ.
- a shift signal appearing on line 32 advances the 1 bit from one register or counter stage to the next, i.e., shifts the l to the next bit position.
- Each bit position is associated with and corresponds to a particular tone generator, so that the presence of the logical l in a particular bit position indicates selection of the tone generator to be claimed next, provided that it is not already claimed.
- This claim select signal is supplied in parallel to one input of a respective one of AND gates 35, on line 36, and to further logic circuitry (to be described presently with reference to FIG. 78), on line 37.
- the output line of each of AND gates 35 is connected to a separate and distinct input line of an OR gate 40 which, in turn, supplies an input to an AND gate 42 whose other input constitutes pulses from the master clock 5.
- shift register stage No. 2 contains the logical 1". That stage therefore supplies claim select 2" signal to the respectively associated AND gate 35 and, as well, to further logic circuitry on line 37. If this further logic circuitry determines that the associated note generator may be claimed, a claimed" signal is applied as the second input to the respectively associated AND gate 35. Since both inputs of that AND gate are now true” an output pulse is furnished via OR gate 40 to the synchronization gate 42. The latter gate produces a shift pulse on line 32 upon simultaneous occurrence of the output pulse from OR gate 40 and a clock pulse from master clock 5. Accordingly, the logical is advanced one bit position, from stage No. 2 to stage No. 3 of shift register 30, in preparation for the claiming of the next tone generator.
- tone generator 28 corresponding to stage No. 3 is already claimed by a previous note pulse in the multiplexed signal.
- a claimed signal appears as one input to the associated AND gate 35, and with the claim select signal appearing as the other input to that gate by virtue of stage No. 3 containing the single logical 1, another shift pulse is immediately generated on line 32 to advance the logical 1 to stage No. 4 of the shift register. Similar advancement of bit position of the 1" continues until an unclaimed tone generator is selected.
- the l bit remains in the shift register stage associated with the selected tone generator until such time as a claimed signal is concurrently applied to the respective AND gate 35, Le, until the selected tone generator is claimed, because until that time no further shift signals can occur.
- each tone generator also has associated therewith a respective portion of the generator assignment logic as shown in that Figure.
- the circuitry of FIG. 78 is associated with the ith tone generator (where i 1, 2, 3, l2), and since each of these portions of the assignment logic is identical, a single showing and description will suffice for all.
- An AND gate 50 has three inputs, one of which is the multiplexed signal deriving from encoder (this being supplied in parallel to the AND gates 50 of the remaining identical portions of the assignment logic for the other tone generators, as well), a second of which is the claim select signal appearing on line 37 associated with the 11th stage of shift register 30 (FIG.
- a modulo 384 counter 55 is employed to permit recognition by the respective portion of the generator assignment logic of the continued existence in the multiplexed signal of the pulse (time slot) which resulted in the capture of the associated tone generator.
- counter 55 is synchronized with keyboard counter I (also a modulo 384 counter) by simultaneous application thereto of clock pulses from master clock 5.
- the count of each counter 55 associated with an uncaptured tone generator is maintained in synchronism with the count of keyboard counter l by application of a reset signal to an AND gate 58 each time the keyboard counter assumes a zero count; i.e., each time the count of the keyboard counter repeats.
- that reset signal is effective to reset counter 55 only if the associated tone generator is uncaptured.
- the latter information is provided by the state of flip-flop 53, i.e., a not claimed signal is supplied as a second input to AND gate 58 whenever flip-flop 53 is in the unclaimed state.
- Capture prevention is effected by feeding a signal representative of zero count from counter 55 to the appropriate input terminal of an OR gate 60 associated with all of the tone generators and their respective generator assignment logic.
- the logical l supplied to OR gate 60 is inverted so that simultaneous identical logical inputs cannot be presented to AND gate 50.
- the zero count is merely snychronized with the zero count of the keyboard counter and is not the result of capture of the associated tone generator it does not interfere with subsequent capture of that tone generator since it does not occur simultaneously with a pulse in the TDM signal.
- a key release indication is obtained by supplying the zero count signal to an AND gate 62 to which is also supplied any signal deriving from an inverter 63 connected to receive inputs from the TDM signal.
- the inversion of the latter pulse prevents an output from AND gate 62, and this is proper because the coincidence of the zero count and the TDM pulse is indicative of continuing depression of the key which has captured the tone generator. Lack of coincidence is indicative that the key has been released, and results in the key release signal. Scanning of the keyboards is sufficiently rapid that any delay which might exist between actual key release and initiation of the key release signal is negligible, and in any event is undetectable by the human senses.
- the generation of a false key release signal when the tone generator is presently unclaimed can have no effect on the audio output of the organ since the associated tone generator is not captured and is therefore not generating any tone.
- the key release signal deriving from AND gate 62 is supplied to attackldelay logic of the tone generator to initiate the decay of the generated tone.
- the set claim" signal output of AND gate 50 that occurs with the simultaneous appearance of the three input signals to that gate is utilized to provide a key depressed indication to the attack/decay circuitry of the tone generator (and to percussive controls, if desired), as well as to provide its previously recited functions of setting flip-flop S3 and resetting counter 55.
- the assignment logic embodiment of FIGS. 7A and 78 may be associated with only a small number of tone generators (twelve, in the example previously given), the exact number being selected in view of the cost limitations and the likely maximum number of keys that normally may be actuated simultaneously. In that case, each tone generator must supply every desired frequency corresponding to every note in every octave that may be played on the electronic organ.
- FIG. 8A illustrates, in block diagrammatic form, an example of a suitable tone generator for generating the frequencies required for the notes selected on the organ keyboards.
- Appropriate frequencies are produced by properly addressing a memory unit containing amplitude samples of the desired waveform obtained at uniformly spaced points in time. Since the sample points are uniformly spaced in time, rather than uniformly spaced on the basis that an integral number of samples be present per cycle for each note frequency, the phase angle between sample points varies according to the frequency of the note to be generated.
- the tone generator system of FIG. 8A demonstrates the teachings of the present invention with regard to addressing a memory unit at selectively controlled rates.
- the keyboard counter 1 is preferably provided with a note or key counter section 2 having at least one additional normally unused count that is to precede the initial count representing the sequence of keys and notes associated therewith.
- This redudant count which is readily provided by merely employing a counter of greater capacity than is needed to handle the minimum count, is utilized to provide a start pulse which precedes the count that occurs each time the keyboard counter is reset to zero.
- a start pulse in the keyboard pulse train may, for example, be assigned to an imaginary key approximately two octaves below the lowest note in each manual.
- this start pulse is the first pulse in the scan, for the illustrative example of scanning from low frequencies to high frequencies on each keyboard, and occurs automatically with reset of the counter 1.
- a memory unit 101 which is to be addressed at any of a number of selectively controlled rates, is preferably a read-only memory containing the digital amplitude values at predetermined sample points of a single cycle of the comlex periodic waveform to be produced for all note frequencies. That is to say, the same complex periodic waveform is to be reproduced for each note played, the only difference being that the phase angle between sample points stored in memory 101 will differ according to the frequency at which the complex waveform is reproduced.
- FIG. 9 illustrating a typical complex waveshape of the type that might be produced by a pipe organ.
- the waveshape shown in FIG. 9 has been sampled at a multiplicity of points, shown as vertical lines in the Figure, to obtain the amplitude data to be stored in memory unit 101. It is only these uniformly spaced samples of amplitude that are stored in the memory and these may be stored in absolute form or in incremental form. In the former case, the data accessed is the actual amplitude of the output waveform at the respective sample point (i.e., with respect to a zero level at the abscissa).
- the amplitude at each sample point as stored in memory 101 is simply the difference in amplitude between the amplitude of the present sample .and the amplitude of the immediately preceding sample.
- Each of the amplitude samples stored in the memory preferably comprises a digital word of approximately seven or eight bits.
- Memory unit 101 may be a microminiature diode array of the type disclosed by R. M. Ashby et al. in U. S. Pat. No. 3,377,513, issued Apr. 9, 1968 and assigned to the same assignee as the present invention.
- the array may, for example, contain an amplitude representation of the desired waveform in the form of an eight bit binary word at each of 48 or more sample points.
- Such a capacity permits the storage of up to one hundred 28 amplitude levels in addition to a polarity (algebraic sign) bit. In any event, the capacity of memory 101 should be sufficient to allow faithful reproduction of each of the note frequencies.
- the system for addressing memory 101 includes a storage register 102 which when reset contains a number representing the phase angle between sample points for the lowest note frequency to be produced by the tone generator.
- the storage register 102 is connected in a recirculating loop 103 which includes a multiplier 104 and a gate 105.
- the purpose of the multiplier is to successively multiply the contents of the storage register by the twelfth root of two (i.e., 2"") for computation of the phase angles between sample points of the complex waveform stored in memory 101 for every note frequency in the entire range of frequencies capable of being generated by the organ. This follows from the fact that in the equal interval, or even temperament, musical scale the note frequencies differ from one another by 2
- the required computation may be performed in either a serial or parallel arrangement.
- the storage register may be l2-bits long, and for serial operation, may recirculate once each 12 bit times.
- the multiplier 104 is specifically constructed and arranged for serial operation.
- the keyboard counter octave section 3 (FIG. 1) advances once each twelve bit times, and hence, the storage register recirculates once each count of the octave section counter.
- phase angle need not be performed in a serial format, however.
- FIG. 88 a parallel arrangement is shown in which the storage register 102 is connected to a scaling circuit 120 which, in turn, is coupled to an adder 121 in the recirculating loop 103.
- the twelfth root of two is approximately equal to 1.000011110011], base 2, which is equivalent to (1 2 -2 +2 2
- the scaling circuit 120 is simply a set of multipliers.
- the adder 121 is preferably a cascaded network of parallel two input adders adapted to receive the outputs of the sealers.
- the phase angle number constituting the result of the addition is then recirculated back to the storage register 102.
- flip-flop is reset upon application of zero count of the octave section counter thereto, and the reset output of the flip-flop also serves to reset the storage register 102.
- the flipflop Upon application of the start pulse of the multiplexed signal to the flipflop, the latter is switched to remove the register reset and to open the gate 105a in recirculating loop 103, thereby allowing the register contents to be multiplied by 2 and re-stored in the register.
- phase angle number which is thereby calculated with each advance of the keyboard count, and which represents a different phase angle between amplitude samples of the waveform stored in memory 101 for each different frequency, is always available when a note generator is captured and is assigned to generate a particular note frequency.
- the modulo 384 counter 55 in the assignment logic associated with the captured note generator is reset to zero, the phase angle number available from the storage register 102, which is the correct phase angle for the selected note, because of the synchronization between the phase angle calculation and the keyboard count, is read into a phase angle register 108, and this occurs each time that modulo 384 counter 55 goes to zero.
- the zero count of counter 55 is applied to a flip-flop 105 (e.g., a one-shot) which is normally set to prevent passage of the phase angle number through an associated gate 106, but which is reset to open the gate 106 to permit passage of the phase angle number therethrough to the phase angle register 108 when the flipflop 105 is reset by the zero count of counter 55.
- a flip-flop 105 e.g., a one-shot
- the overall phase angle calculator and the read-only memory 101 may be shared by all of the tone generator 28.
- Each tone generator is addressed individually in the sequence of addressing all tone generators.
- an auxiliary sampling clock (not shown) may be utilized which comprises a clock rate, provided by the master sampling clock, successive clock pulses of which are directed to the series of tone generators.
- the sampling clock addressed to a given tone generator is thus at a rate comprising the pulse repetition rate of the master sampling clock divided by the number of tone generators provided in the system.
- an accumulator 104a associated with the memory may be a composite structure associated with appropriate gating circuitry related to each tone generator for accumulating the information read from memory 101 in response to accessing thereof by a given tone generator.
- phase angle value stored in the respective phase angle register 108 is added to the previously stored value in a sample point address register 109.
- An address decoder 110 decodes preselected bit positions of the count established in register 109 to effect addressing of memory unit 101. It is important to note that during addressing of memory 101, it is the rate at which the value of the sample point address register 109 increases, and not the absolute value of its contents, which is significant in the control of the rate of readout of the memory 101, and thus in the control of the frequency of the note produced by the given tone generator.
- phase angle number comprising a digital binary word
- the amplitude data in the memory location corresponding to the sample point address then contained in register 109 is accessed.
- each register must "be of a finite, practical length. In particular, the length of each register must be determined by the accuracy with which the frequency of the note is to be generated.
- the frequency actually produced is precisely the value of the phase angle multiplied by the clock rate at which the contents of the phase angle register are supplied to the address register 109.
- the rate at which the memory unit 101 is addressed also changes.
- the sample point address register 109 is incremented by the value of the phase angle number at each auxiliary clock time. That is to say, once each clock time, the phase angle number is added to the sample point address register. Only a relatively small number of bits in the region of least significance of the address register contents are used to designate the sample point addressed in memory 101 and these bits are arranged to be incremented at a rate which depends upon the phase angle number.
- no new address may be specified for several increases in the address-identifying number.
- a sample point address in the memory is identified, and the memory is addressed for retrieval of the data contained in the specified location, for each increment of the address register dictated by the phase angle number.
- the incrementing of the sample point address register is such that new addresses are identified only after a corresponding number of repetitions of the phase angle number at the fixed clock frequency.
- the same effect is achieved by use of an address decoder 110.
- the digital words thus read from memory unit 101 are supplied to an accumulator 1042 which provides a digital representation of the waveform at selected sample points over a cycle of the waveform and at a frequency corresponding to the note to be reproduced.
- this digital waveform representation may itself be operated upon for waveshape control (for exam ple, attack and decay) and is subsequently supplied to a digital-to-analog converter for producing an analog signal suiable for driving the acoustical output means, such as audio speakers, of the organ.
- An electronic organ including a keyboard having a plurality of keys respectively associated with notes of themusical scale, said keys being operable, when actuated, to develop signals for calling forth respectively associated notes as audible tones of the desired note frequencies from said organ, and a tone generator said tone generator comprising:
- a memory storing amplitude samples of a waveform to be reproduced at the desired note frequencies, said amplitude samples of the waveform being taken at points uniformly spaced in time over a cycle thereof,
- clock means establishing a fixed rate of accessing amplitude samples of said waveform from said memory
- a tone generator for synthesizing frequencies of the notes of the musical scale in an electronic musical instrument, the instrument including means for selecting the notes to be synthesized, said generator comprism nemory means for storing amplitude values of a waveform to be reproduced at the desired note frequencies, said amplitude values of the waveform being taken at uniformly spaced points in time over one cycle of the waveform,
- a note frequency number register for storing the establishing the rate of addressing said memory.
Abstract
A memory contains digital data of related informational content in a plurality of discrete locations identified by respective addresses. The memory is addressed, or accessed, at a rate which depends upon the desired spacing between data from the various locations as it is sequentially read from the memory. In a specific embodiment, the data constitutes amplitude values of a complex waveform of the type produced by a musical instrument, at equally spaced points in time along an axis of the waveform. Apparatus for addressing the memory at any of a plurality of selectively controlled rates includes a calculator for continuously computing a set of numbers each defining a different spacing between the data during readout of the memory. When a desired rate of readout is selected, as by selecting a desired frequency of repetition of a complete cycle of the stored waveform, the number associated with that rate is sampled from the computed set and is periodically increased by its own value to identify appropriate data addresses in the memory, for accessing that data, at intervals of the periodic increase corresponding to the desired rate of readout.
Description
Watson METHOD AND APPARATUS FOR ADDRESSING A MEMORY AT SELECTIVELY CONTROLLED RATES [75] Inventor: George A. Watson, Tustin, Calif. [73] Assignee: North American Rockwell Corporation, El Segundo, Calif. [22] Filed: Aug. 11, 1971 [21] Appl. No.: 170,992
Related US. Application Data [62] Division of Ser. No. 875,178, Nov. 10, 1969, Pat. No.
[52] U.S. Cl. 84/1.0l, 84/103 [51] Int. Cl. GlOh /00 [58] Field of Search 84/1.0l, 1.03; 340/1725 [56] References Cited UNITED STATES PATENTS 3,163,850 12/1964 Austin et a1. 340/1725 3,267,433 8/1966 Falkoff 340/1725 3,328,770 6/1967 Silver 340/1725 3,337,852 8/1967 Lee et a1 340/1725 3,417,378 12/1968 Simonsen et a1. 340/1725 3,696,201 /1972 Arsem et al. 84/].01
3,697,661 10/1972 Deutsch 84/l.0l
3,700,781 10/1972 Obayashi 84/l.01
3,515,792 6/1970 Deutsch.... 84/103 3,610,799 10/1971 Watson 84/1.0l
[ l l l 3,743,755 July 3, 1973 [57] ABSTRACT A memory contains digital data of related informational content in a plurality of discrete locations identified by respective addresses. The memory is addressed, or accessed, at a rate which depends upon the desired spacing between data from the various locations as it is sequentially read from the memory. In a specific embodiment, the data constitutes amplitude values of a complex waveform of the type produced by a musical instrument, at equally spaced points in time along an axis of the waveform. Apparatus for addressing the memory at any of a plurality of selectively controlled rates includes a calculator for continuously computing a set of numbers each defining a different spacing between the data during readout of the memory. When a desired rate of readout is selected, as by selecting a desired frequency of repetition of a complete cycle of the stored waveform, the number associated with that rate is sampled from the computed set and is periodically increased by its own value to identify appropriate data addresses in the memory, for accessing that data, at intervals of the periodic increase corresponding to the desired rate of readout.
6 Claims, 12 Drawing Figures z'rno COUNT 0F j OCTAVE SECTION 3 "5mm" cou-T- iic /li 103 A READ-ONLY (185K MEMORY :01 CLOCK PULSES STORAGE REGISTER 106 we PHASE ANGLE PHASE ANGLE GATE L=: REGISTER NUMBER lL I09 MULTlPLlER (by 2 SAMPLE POINT s ADDRESS I04 REGISTER ZERO cou-r 0F COUNTER 3105a 110 OUTPUT TO D/A CONVER YER PATENIEBJHL 3 I973 SHEU 2 UF 5 FROM 32 AND GATES 8 FROM I2 STAGES OF NOTE OF DECODER 7 SECTION 2 (KEYBOARD COUNTER I) MULTIPLEXED SIGNAL 25 SWITCHING ARRAY N @L R 5 XA ELK I EN C R) L m m m l s M Om U Mmv U M E 1. O 8 W H S 23 HP RRR RR cvSQu SS F. M II L R l n r: r! N w C II 2 FL {I L 0 Mll N I 1| M R l 8 ER I: SA A U6 3 N m U W 6 UW Os PATENTEB JUL 3 I975 SHEET 3 (If 5 KEY CONTACT NOTES PLAYED) R4 TIME lREsEr COUNTER ZERO TONE GENERATORS (I- I2I GENERATOR ASSIGNMENT LOGIC MULTIPLEXED SIGNAL (SAMPLE POINTS) PAIENIEBJIIL aIsTs 3.743.755
CLAIM sELECT CLAIMEDI M SELECTZ I MASTER I I I I I I I I l I I I I l l l I I l l I l I I I I I MSELECTIZ MASTER CLoCK RESET MOD 384 ZERO COUNT i 58 COUNTER COUNTER RESET KEY RELEASE 'NVERT SIGNAL To I\ ATTACI V 62 DECAY LOGIC KEY DEPRESSED ET IBITI sET CLAIM IIIIIII TI II T M PERCUSSIVE SET CLAIMED I TO TONE CLAIM I CLAIM I GEN 28i CONTROL SELECT 5 w 50 DECAY NOT CLAlMED 37 COMPLETE ZERO COUNT DETECTOR BACKGROUND OF THE INVENTION The present invention is directed generally toward the addressing of a memory containing digital data of related informational content in successive or sequential data locations, or addresses, therein. The data may, for example, consist of digital samples of the amplitude of a waveform at successive selected points, or may consist of a list of symbols identifying in a particular order the members of a class of prescribed characteristics, or may consist of a mathematical progression of numbers, or may consist of other information.
It is sometimes necessary or desirable to read data from a memory unit in which it is stored at a controllably variable rate. For example, in the case of stored amplitude samples of a waveform, the rate at which the samples are read from the memory can be used to determlne the frequency of the output waveform, or the phase angle of the waveform relative to a fixed reference. Alternatively, if the rate at which samples are read from the memory is held constant, the frequency of the output waveform may be varied by changing the rate at which the address changes. In the latter case, the same data may be read from the memory several times in succession where the address is unchanged through several access commands, so that the same memory location is addressed each time. For certain types of stored data, no difficulty may be encountered with such a process. If the data in a specified memory location cannot be read out repetitively, without destroying the significance of the data, then special means must be devised to prevent supplying that data on a repeated basis to its ultimate processing circuitry to ensure that the same data is supplied only once, during a specific sequence, to subsequent processing circuitry.
SUMMARY OF THE INVENTION Broadly, the invention includes means for performing a calculation to derive a number that determines the rate at which the memory shall be accessed, regardless of the consistency of the clock rate at which the overall system is operated. The calculating means continuously calculates a'set of distinct and different numbers, and means are provided to select a desired number that will produce a predetermined rate ofaccessing of the memory based on the occurrence of a related oneof a set of selected events. Thus, if an event occurs, the number with which that event is associated is selected and determines the rate at which the memory is accessed. Evey number is periodically calculated in cyclic sequence to ensure its availability when the event with which it is associated occurs. I
In a specific embodiment demonstrating an exemplary application of the invention, a memory unit in a digital electronic musical instrument is addressed at a rate which is selectively controllable according to the frequency (or phase angle relative to a reference phase) of the note to be produced by the instrument. The memory unit contains digital data representing samples of the amplitude of a complex waveform at a plurality of uniformly spaced points in time (i.e., along the abscissa, or time axis, of the waveform). The complex waveform is identical for each note, but its rate of cyclic repetition is to be varied according to the frequency of the note to be played. The individual amplitude samples are stored in separate locations, preferably at sequential addresses although this is not absolutely necessary, of a read-only memory (ROM), and the memory is thereafter addressed, i.e., the stored data is accessed or read out, at a rate which depends upon the frequency of the note to be generated by the instrument.
In a digital electronic organ of the type specifically disclosed in the copending application of George A. Watson entitled Multiplexing System for Selection of Notes and Voices in an Electronic Musical Instrument, filed Oct. 30, 1969 and issued Oct. 5, 1971 as U. S. Pat. No. 3,610,799 the instrument has a plurality of keyboards, including at least one manual and at least one pedal division. Each keyboard may cover several octaves. When a key is depressed on any keyboard of the digital electronic organ, a sound waveform is to be generated with a periodicity corresponding to the desired note frequency. The waveform is computed in digital format consisting of a series of digital words which represent the magnitude of the waveform at a series, or sequence, of uniformly spaced sample points. The digital sample point values thus generated are subsequently converted to analog form.
The sample points are preferably uniformly spaced because such a format permits the most direct analysis, and therefore the most direct synthesis, of the desired waveform. If desired, the uniform spacing of sample points may be such that there is provided an integral number of samples per cycle for each note frequency to be generated. Such a technique requires a sampling rate that varies directly with the frequency. Alternatively, the samples may be spaced uniformly in time, in which case the number of sample points differs according to frequency, and the phase angle between sample points varies with the frequency of the note to be generated. Although the synthesis of a multiplicity of note frequencies can be implemented for either technique, using a single clock frequency, the preferred frequency synthesis technique is that in which the phase angle between the sample points varies with frequency, i.e., in which the sampling rate is fixed for all note frequencies to be generated, and the various generated note frequencies are produced as a result of the different phase angles.
According to a specific application of the memory addressing technique of the present invention, then, there is provided a means for continuously calculating phase angles, to make available to a selection means any desired phase angle corresponding or related to a specific frequency, the selection means being governed by frequency criteria dependent on the note associated with the depressed key. The selection of a particular phase angle is translated into a sample point address in the memory unit within which the digital values representing amplitude samples of the waveform are stored.
As the phase angle changes, the rate at which the memory unit is addressed changes. This is accomplished by providing an address register to which the phase angle number is supplied, and which is incremented according to the value of the phase angle number. That is to say, once each clock time, the phase angle number is added to the sample point address register. Only a relatively small number of bits of rather low significance in the latter register are used to designate the sample point addresses, and these bits are arranged to be incremented at a rate which depends upon the phase angle number, so that a new address may or may not be specified for several periodic increases in the address-identifying word. In the limit, an actual sample point address in the memory is identified and the memory is thereupon appropriately accessed for retrieval of the data contained at those addresses, for each increment dictated by the phase angle number. This limit is the uppermost note frequency that can be generated by the organ. For lower frequencies, the incrementing of the sample point address register is such that new addresses are identified only after a corresponding number of repetitions of the phase angle number, at the fixed clock frequency.
Accordingly, it is the principal object of this invention to provide a method and apparatus for addressing a memory at any one of several selectively controllable rates.
It is another object of this invention to provide methods and apparatus consistent with the object set forth immediately above, in which the memory unit contains digital data of related information content, so arranged or so located that sequential addresses of the memory are to be read out in sequence.
Still another object of this invention is to provide a method and apparatus as set forth above, specifically for use in the tone generating system of a digital electronic musical instrument.
BRIEF DESCRIPTION OF THE DRAWINGS In describing the present invention, reference will be made to the accompanying figures of drawing, in which:
FIG. I is a simplified block diagram of a portion of a digital electronic organ system whose overall structure and function demonstrates a specific application of the controllable readout of a memory in accordance with the invention, in which portion a time division multiplexed signal is produced containing a recycling sequence of time slots each associated with a particular key of the organ, the contents of each time slot indicating whether the associated key has been actuated;
FIG. 2 is a circuit diagram of an exemplary decoder for use in the system of FIG. I;
FIG. 3 is a more detailed circuit diagram of the switching array and encoder used in the system of FIG.
FIG. 3A is a circuit diagram of an alternative encoder to that shown in FIG. 3, for use in the system of FIG,
FIG. 4 is a circuit diagram of the input-output bus connecting means at each intersection in the switching array of FIG. 3;
FIG. 5 is illustrative of a multiplexed waveform developed by the system of FIG. 1 and responsive to actuation of selected keys;
FIG. 6 is a simplified block diagram of a generator assignment and tone generating apparatus for processing the multiplexed signal produced by the system of FIG. I to develop the desired tones as an audible output of the organ;
FIG. 7A and 7B together constitute a circuit diagram of one embodiment of the tone generator assignment logic for the system of FIG. 6;
FIG. 8A is a block diagram of a tone generator employing the principles of the present invention with regard to selective rate of addressing a memory, for use with assignment logic of FIGS. 7A and 7B in the system of FIG. 6;
FIG. 8B is a block diagram of an alternate embodiment of a portion of the tone generator of FIG. 8A; and
FIG. 9 is illustrative of a complex waveshape of the type produced by a pipe organ, and of the sample points at which amplitude values are taken for simulation at selected note frequencies.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, the keyboard multiplexing system or note selection system includes a keyboard counter l which is implemented to provide a specified count for each key of each keyboard (including manuals and pedal divisions) of the organ. If, for example, the electronic organ in which the multiplexing system is used has four keyboards, such as three manuals and a pedal board, each encompassing up to eight octaves, then keyboard counter 1 should have the capability of generating 4 X 8 X 12 384 separate counts (digital words). It is essential that the counter be capable of developing a count representative of every key on every keyboard of the organ; however, it may be desirable to provide a counter that can produce a count greater than the number of available keys in order to have available certain redundant counts not associated with any keys. Such redundancy is readily provided by simply utilizing a counter of greater capacity than the minimum required count.
Advancement of the count of counter 2 is accomplished by application of clock pulses thereto from a master clock source 5 which delivers clock pulses at a sufficiently rapid repetition rate (frequency) to ensure resolution of depression (actuation) and release (deactuation) of any key on any keyboard, i.e., to supply a pulse at the instant of either of these events. Scanning of all keyboards of the organ at a rate of 200 or more times a second is deemed quite adequate to obtain this desirable resolution. For the exemplary keyboard counter set forth above, this is equivalent to a minimum of 200 X 384 76,800 counts per second, so that a master clock delivering clock pulses at a rate of 100 KC/s is quite suitable.
A total of four lines emanate from counter 4, one line connected to each ring counter stage, to permit sensing of the specific keyboard which is presently being scanned. Similarly, eight lines are connected to the eight ring counter stages, respectively, of octave counter 3 to detect the octave presently being scanned.
Thus, a total of 12 lines extend from counters 3 and 4, and these twelve lines can carry signals indicative of 32 (8 X 4) possible states of the keyboard counter. The specific one of the 32 states, representative of a particular octave on a particular keyboard, which is presently being scanned is determined by use of a decoder circuit 7 composed of 32 AND gates designated 8-1, 8 2, 8-3, 8-32 (FIG. 2), each with two input terminals and an output terminal. The gates are arranged in four groups of eight each, with every gate of a particular group having one of its two input terminals (ports) connected to one of the four lines of counter 4. Distinct and different ones of the eight lines from counter 3 are connected to the other input terminal of respective ones of the eight AND gates of that group. A corresponding situation exists for each group of AND gates, with the only difference being that each group is associated with a different output line of counter section 4. Using this arrangement, the decoder logic designates every octave of keys in the organ by a respective driver pulse when a count corresponding to that octave is presently contained in the counter.
The output pulses derived from the AND gates (or drivers) of decoder circuit 7 are supplied on respective ones of 32 bus bars (or simply, buses), generally designated by reference numeral 10, to a keyboard switching array ll. From the preceding descripton, then, it will be clear that array 11 has one input bus 10 for every octave of keys in the organ (including every octave on every keyboard), and that a drive pulse will appear on each input bus approximately 200 times per second, the exemplary rate of scan of the keyboard, as noted above, for obtaining adequate resolution of operation of the keys. Switching array 11 also has twelve output buses, generally designated by reference number 12, each to be associated with a respective one of the twelve notes (and hence, the twelve keys) in any given octave.
Array llli is basically a diode switching matrix, in which spaced input buses It) and spaced output buses 12 are orthogonally arranged so that an intersection or crossing occurs between each input bus and each output bus (see FIG. 3), for a total of 384 intersections, one for each count of the keyboard counter 1. As is typical in this type of matrix, the crossed lines or buses are not directly interconnected. Instead, a jump diode, such as that designated by reference number 113 in FIG. 4, is connected between the input bus 10 and the output bus 12 at each intersection, the diode poled for forward conduction (anode-to-cathode) in the direction from an input bus 10 to an output bus 12. Wired in series circuit or series connection with each diode 13 is a respective switch 14 which is normally open circuited and is associated with a distinct respective one of the keys of the organ, such that depression of the associated key produces closure (close circuiting) of the switch 14 whereas release of the associated key results in return of the switch to its open state. Alternatively,
each of switches 14 may itself constitute a respective key of the various keyboards of the organ.
While switch 14 is shown schematically as being of mechanical single pole, single throw (SPST) structure, it will be understood that any form of switch, electronic, electromechanical, electromagnetic, and so forth, may be utilized, the exact nature of the switch depending primarily upon the nature of the energization produced upon operation of the associated key. Switch 14, then, is adapted to respond to the particular form of enerization or actuation produced upon operation of a key on any keyboard (or, as observed above, may itself constitute the key), to complete the circuit connecting associated diode 13 between a respective input bus 10 and a respective output bus 12 at the intersection of those buses, when the key is depressed, and to open the circuit connecting the diode between respective input and output buses at that intersection when the key is released. Positive pulses occurring at the rate of approximately 200 per second, for example, according to the timing established by master clock 5, are transferred from input bus 10 to output bus 12 via the respective diode l3 and closed switch 14 when the associated key is depressed. While a switch alone (i.e., without the series connected diode) would serve the basic purpose of transferring a signal between the input and output lines of array 11, the diode provides a greater degree of isolation from sources of possible interference (noise) and acts to prevent feedback from output to input lines.
In FIG. 3, the output buses 12 from switching array 11 are connected to an encoder circuit 15 to which are also connected the twelve output lines, generally designated by reference number 16, from keyboard counter section 2. To produce an orderly arrangement in which each key of the organ is assigned a distinct and different time slot in a time-division multiplex waveform, the switches 14 associated with the respective keys are conveniently arranged in a specific sequence in the switching array 11. Assume, for example, that a specific output bus 17 of the switching array is to be associated with note A of any octave, a second output bus 18 is to be associated with note B of any octave, and so forth. Then switches 14 in the row corresponding to output bus 17 in array or matrix 11 are associated with the keys corresponding to the note A in each octave of keys in the organ. The column position of each switch 14 in matrix I 1 corresponds to a specific octave of keys in the organ, and hence, to a specific octave encompassed by a specific keyboard of the organ.
Each of the output buses 12, including l7, l8, and so forth, is connected to one of the two input ports or terminals of a respective AND gate of the twelve AND gates 20-1, 20-2, 20-3, 20-12, of encoder circuit 15. An output lead 16 of counter section 2 associated with the ring counter stage designating the count for a particular note (key) in a given octave is connected to the remaining port of an encoder circuit AND gate having as its other input a pulse on the output bus 12 associated with that same note. A similar arrangement is provided for each of the remaining eleven output lines 16 of counter section 2 with respect to the AND gates 20 and the output buses 12. Thus, for example, if output bus 17 (associated with the row of switches 14 in matrix 1 l for note A) is conected to one input terminal of AND gate 20-1, then output line 22 from the stage of counter 2 designating the count associated with note A is connected to the remaining input terminal of gate 20-1. The output terminal of each of AND gates 20 is connected to a respective input terminal of OR gate 23, the output of the OR gate constituting the output signal of the encoder circuit. By virtue of its structure, encoder circuit is effective to convert the parallel output of array 11 to a serial output signal in accordance with the scanning of output buses 12 as provided by the advancing and repeating count sensed in the form of pulses (at a-rate of about 200 per second) appearing on output lines 16. The end result of this circuitry is the production of a time-division multiplex (TDM) signal on a single conductor 25 emanating from encoder 15.
As an alternative to the specific logic construction shown for encoder 15 in FIG. 3, the encoder may have the circuit configuration exemplified by FIG. 3A. Referring to the latter Figure, the encoder includes a shift register 80 having twelve cascaded stages designated SR1, SR2, SR3, SR12, each connected to a respective output bus 12 of switching matrix 11 to receive a respective output pulse appearing thereon. The shift register stages are loaded in parallel with the data read from switching array 11 on output buses 12, in response to each of the pulses appearing (i.e., each time a pulse appears) on one of the 12 output leads 16 of note counter 2. That one output of the note counter which is to supply the load command for all twelve stages of shift register 80 is selected to permit the maximum amount of settling time to elapse between each advance of octave counter 3 and keyboard counter 4 and the loading of the shift register. In other words, it is extremely desirable that the data to be entered into the shift register from the switching array be stabilized to the greatest possible extent, and this is achieved by allowing the counters whose scanning develops this data, to settle at least immediately prior to loading. Thus, the first note counter stage, or one of the early stages, is selected to provide load pulses to shift register 80.
Shift pulses are supplied to the shift register by master clock 5, which also supplies note counter 2, to shift the contents of each shift register stage to the next succeeding stage except during those bit times when the shift pulse is pre-empted by a load pulse from the note counter. Accordingly, shift register 80 is parallel loaded, and the data contents of the register are then shifted out of the register in serial format on encoder output line 25 until a one-bit pause occurs when another set of data is parallel loaded into the shift register, followed again by serial readout on line 25. This serial pulse train constitutes the time division multiplexed output signal of encoder 15 just as in the embodiment of FIG. 3, except that with the FIG. 3A configuration, decoder 7 (and the counters 3 and 4 supplying pulses thereto) undergo a greater amount of settling time.
It will be observed that this operation consitutes a parallel-to-serial conversion of the information on output buses 12 to a time-division multiplexed waveform on the output line 25 of encoder 15.
In the TDM signal, each key has a designated time slot in the 384 time slots constituting one complete scan of every keyboard of the organ. In the specific example of the time base provided by master clock 5, the TDM waveform (shown by way of example in FIG. 5) is initiated about 200 times per second. This waveform contains all of the note selection information, in serial digital form on a single output line, that had heretofore required complex wiring arrangements. This waveform development will be more clearly understood from an example of the operation of the circuitry thus far discussed. It should be observed first, however, that all of the counter and logic circuitry described up to this point can be accommodated within a very small volume of space by fabrication in integrated circuit form using conventional microelectronic manufacturing techniques.
When the main power switch for the electronic organ is turned on, all components are energized to an operational state, the master clock delivering pulses to keyboard counter l at the aforementioned rate. Upon depression of a key on any keyboard of the organ, including the manuals and pedal divisions, a respective switch 14 associated in series connection with a diode 13 at the intersection between the appropriate input bus 10 and output bus 12 of the switching array 11 is closed, thereby connecting the two buses to supply pulses appearing on a given bus 10 from decoder 7, to the appropriately connected output bus 12 for application to encoder 15. If, for example, the key that was depressed is associated with note C in the second octave, C appears in the appropriate time slot of the multiplexed signal emanating from encoder and will repetitively appear in that time slot in each scan of the keyboards of the organ as long as that key is depressed. That is to say, a pulse appears on output line 10 of decoder 7 associated with the second octave in the manual being played, in accordance with the scan provided by master clock 5, as the counter stage associated with that octave is energized in keyboard counter octave section 3 and the counter stage associated with that manual is energized in section 4 of the keyboard counter. The connection between the appropriate input bus 10 and output bus 12 of switching array 11 for the particular octave and keyboard under consideration is effected by the depression and continued operation of the key associated with the switch 14 for that intersection in the array. Since, as previously stated, each switch is associated with a particular note (key) and is positioned in a specific row of the switching array, a signal level is thereby supplied to the appropriate output bus 12 of the switching array arranged to be associated with that note. Each time the specified note, here the note C, is scanned in the sequence of count in the note section 2 of the keyboard counter, a second input is provided to the AND gate 20 receiving the signal level on output bus 12, and a pulse is delivered to OR gate 23. By virtue of this operation, the pulse which appears at the output of OR gate 23 always appears in the identical specified time slot in the multiplexed signal for a specific note associated with a particular key on a particular keyboard of the organ.
If more than one key is depressed, regardless of whether one or more keyboards is involved, operation corresponding to that described above for a single depressed key is effected for every operated key. Thus, for example, assume that the key associated with note C is played on one manual, the note B is played on a second manual, and the notes D,,, E and G are played on a third manual, the associated keys being depressed substantially simultaneously to produce desired simultaneous reproduction of all notes as the audio output of the organ. Under these conditions, the associated switches 14 in the switching array 11 are closed to provide through connections between the respective input buses 10 and output buses 12 for the specific octaves and manuals involved. As the appropriate AND gates in encoder 15 are supplied with gating signals from the sequentially energized counter stages of note section 2, during the scanning operation provided by that keyboard counter section, pulse levels appearing on output buses 12 for which switches 14 have been closed are gated in the appropriate time slots of the multiplex signal on the output lead from OR gate 23 of encoder 15, for the specific notes involved.
An example of the multiplex signal waveform thus generated is shown in FIG. 5. While the pulses appearing in the time slots associated with the specific notes mentioned above are in a serial format or sequential order, their appearance is repetitive during the interval in which the respective keys are actuated. Hence, the effect is to produce a simultaneous reproduction of the notes as an audio output of the organ, as will be explained in more detail in connection with the description of operation of the tone generation section.
Referring now to FIG. 6, the multiplexed signal arriving from encoder 15 is supplied to generator assignment logic network 26 which functions to assign a tone generator 28 to a depressed key (and hence, to generate a particular note) when the associated pulse first appears in its respective time slot in the multiplexed signal supplied to the assignment logic. If only 12 tone generators 28 are available in the particular organ under consideration, for example, the assignments are to be effected in sequence (order of availability), and once particular pulses have been directed to all of the available generators (i.e., all available tone generators have been captured by respective note assignments), the organ is in a state of saturation. Therafter, no further assignments can be made until one or more of the tone generators ls released. The availability of 12 (or more) tone generators, however, renders it extremely unlikely that the organ would ever reach a state of saturation since it is quite improbable that more than twelve keys would be depressed in any given instant of time during performance of a musical selection. The output waveforms from the captured tone generators at the proper frequencies for the notes being played, are supplied as outputs to appropriate waveshaping and amplification networks and thence to the acoustical output speakers of the organ. If the tone generators 28 supply a digital representation of the desired waveform, as is the case in one embodiment to be described, then the digital format is supplied to an appropriate digitalto-analog converter, which in turn supplies an output to the waveshaping network.
At any given instant of time, each tone generator 28 may be in only one of three possible states, although the concurrent states of the tone generators may differ from one tone generator to the next. These three states are as follows:
1. a particular note represented by a specific pulse in the multiplexed signal has captured (i.e., claimed) the tone generator;
2. the tone generator is presently uncaptured (i.e., unclaimed or available), but wlll be captured by the next incoming pulse in the multiplexed signal associated with a note which is not presently a tone generator captor; and
3. the tone generator is presently available, and will not be captured by the next incoming pulse.
It should be apparent from this delineation of possible states that any number of the tone generators provided (12, in this particular example) may be in one or the other of the states designated (1) and (3), above, but that only one of the tone generators can be in state (2) during a given instant of time. That is, one and only one generator is the next generator to be claimed. When the specific tone generator in state (2) is claimed by an incoming pulse, the next incoming pulse which is not presently claiming a tone generator is to be assigned to the generator that has now assumed state (2). For example, if the third tone generator (No. 3) of the 12 generators is captured by an incoming pulse (note representation) and the fourth generator (No. 4) was and still is captured by a previous note selection, then tone generator No. 4 is unavailable to the next incoming pulse, and the privilege of capture must pass to the next tone generator which is not presently in a state of capture. If all of the tone generators are captured, that is, all are in state (las described above, then the organ is saturated and no further notes can be played until at least one of the tone generators is released. As previously observed, however, the saturation of an organ having 12 (or more) tone generators is highly unlikely. Generator assignment system 26 is utilized to implement the logic leading to the desired assignment of the tone generators 28, and thus to the three states of operation described above. An exemplary embodiment of the generator assignment logic is shown in FIGS. 7A and 78. Referring to FIG. 7A, a ring counter 30, or a 12-bit recirculating shift register in which one and only one bit position is a logical l at any one time, is used to introduce a claim selection, i.e., to initiate the capture, of the next available tone generator in the set of tone generators 28 provided in the organ. A shift signal appearing on line 32 advances the 1 bit from one register or counter stage to the next, i.e., shifts the l to the next bit position. Each bit position is associated with and corresponds to a particular tone generator, so that the presence of the logical l in a particular bit position indicates selection of the tone generator to be claimed next, provided that it is not already claimed.
Each time the logical 1" appears in a stage of shift register 30, a claim select signal appears on the respective output line 34 associated with the stage. This claim select signal is supplied in parallel to one input of a respective one of AND gates 35, on line 36, and to further logic circuitry (to be described presently with reference to FIG. 78), on line 37. The output line of each of AND gates 35 is connected to a separate and distinct input line of an OR gate 40 which, in turn, supplies an input to an AND gate 42 whose other input constitutes pulses from the master clock 5.
In operation of the portion of the generator assignment logic shown in FIG. 7A, assume that shift register stage No. 2 contains the logical 1". That stage therefore supplies claim select 2" signal to the respectively associated AND gate 35 and, as well, to further logic circuitry on line 37. If this further logic circuitry determines that the associated note generator may be claimed, a claimed" signal is applied as the second input to the respectively associated AND gate 35. Since both inputs of that AND gate are now true" an output pulse is furnished via OR gate 40 to the synchronization gate 42. The latter gate produces a shift pulse on line 32 upon simultaneous occurrence of the output pulse from OR gate 40 and a clock pulse from master clock 5. Accordingly, the logical is advanced one bit position, from stage No. 2 to stage No. 3 of shift register 30, in preparation for the claiming of the next tone generator.
Suppose, however, that the tone generator 28 corresponding to stage No. 3 is already claimed by a previous note pulse in the multiplexed signal. In that event a claimed signal appears as one input to the associated AND gate 35, and with the claim select signal appearing as the other input to that gate by virtue of stage No. 3 containing the single logical 1, another shift pulse is immediately generated on line 32 to advance the logical 1 to stage No. 4 of the shift register. Similar advancement of bit position of the 1" continues until an unclaimed tone generator is selected. If it should happen that no note is presently being selected on a keyboard of the organ at the time when an unclaimed tone generator is selected, the l bit remains in the shift register stage associated with the selected tone generator until such time as a claimed signal is concurrently applied to the respective AND gate 35, Le, until the selected tone generator is claimed, because until that time no further shift signals can occur.
Referring now to FIG. 73, each tone generator also has associated therewith a respective portion of the generator assignment logic as shown in that Figure. In other words, the circuitry of FIG. 78, with minor exceptions to be noted in the ensuing description, is associated with the ith tone generator (where i 1, 2, 3, l2), and since each of these portions of the assignment logic is identical, a single showing and description will suffice for all. An AND gate 50 has three inputs, one of which is the multiplexed signal deriving from encoder (this being supplied in parallel to the AND gates 50 of the remaining identical portions of the assignment logic for the other tone generators, as well), a second of which is the claim select signal appearing on line 37 associated with the 11th stage of shift register 30 (FIG. 7A), and the third of which is a signal, on line 52, indicating that the pulse in the multiplexed signal has not captured any tone generator as yet. Of course, these signals are not present unless the respective events which produce them are actually occurring, but if all three signals are simultaneously presented as inputs to AND gate 50, a set" signal is applied to a claim flip-flop 53 to switch that flip-flop to the claimed state and simultaneously therewith to supply a claimed signal to the AND gate 35 associated with the 11th stage of shift register 30 and to the respectively associated tone generator 28.
A modulo 384 counter 55 is employed to permit recognition by the respective portion of the generator assignment logic of the continued existence in the multiplexed signal of the pulse (time slot) which resulted in the capture of the associated tone generator. To that end, counter 55 is synchronized with keyboard counter I (also a modulo 384 counter) by simultaneous application thereto of clock pulses from master clock 5. The count of each counter 55 associated with an uncaptured tone generator is maintained in synchronism with the count of keyboard counter l by application of a reset signal to an AND gate 58 each time the keyboard counter assumes a zero count; i.e., each time the count of the keyboard counter repeats. However, that reset signal is effective to reset counter 55 only if the associated tone generator is uncaptured. The latter information is provided by the state of flip-flop 53, i.e., a not claimed signal is supplied as a second input to AND gate 58 whenever flip-flop 53 is in the unclaimed state.
When the flip-flop and hence, the associated tone generator) is claimed, however, it is desirable to indicate the time slot occupied by the pulse which effected the capture, and for that reason a reset signal is applied to counter 55 at any time that an output signal is derived from AND gate 50. Thus, in the captured state, the zero count of counter 55 occurs with each repetition of the capturing pulse in the TDM waveform. Such information is valuable for a variety of reasons; for example, to prevent capture of an already captured tone generator when the zero count continues to appear simultaneously with a pulse in the TDM waveform, and to provide a key released indication when the zero count is no longer accompanied by a pulse in the TDM waveform. Capture prevention is effected by feeding a signal representative of zero count from counter 55 to the appropriate input terminal of an OR gate 60 associated with all of the tone generators and their respective generator assignment logic. The logical l supplied to OR gate 60 is inverted so that simultaneous identical logical inputs cannot be presented to AND gate 50. On the other hand, when the zero count is merely snychronized with the zero count of the keyboard counter and is not the result of capture of the associated tone generator it does not interfere with subsequent capture of that tone generator since it does not occur simultaneously with a pulse in the TDM signal. A key release indication is obtained by supplying the zero count signal to an AND gate 62 to which is also supplied any signal deriving from an inverter 63 connected to receive inputs from the TDM signal. If the zero count coincides with a pulse in the multiplexed signal, the inversion of the latter pulse prevents an output from AND gate 62, and this is proper because the coincidence of the zero count and the TDM pulse is indicative of continuing depression of the key which has captured the tone generator. Lack of coincidence is indicative that the key has been released, and results in the key release signal. Scanning of the keyboards is sufficiently rapid that any delay which might exist between actual key release and initiation of the key release signal is negligible, and in any event is undetectable by the human senses. Furthermore, the generation of a false key release signal when the tone generator is presently unclaimed, as a result of the occurrence of a zero count from counter 55 synchronized with the zero count of the keyboard counter and the simultaneous absence of a pulse in the TDM signal, can have no effect on the audio output of the organ since the associated tone generator is not captured and is therefore not generating any tone. In any case, the key release signal deriving from AND gate 62 is supplied to attackldelay logic of the tone generator to initiate the decay of the generated tone.
The set claim" signal output of AND gate 50 that occurs with the simultaneous appearance of the three input signals to that gate is utilized to provide a key depressed indication to the attack/decay circuitry of the tone generator (and to percussive controls, if desired), as well as to provide its previously recited functions of setting flip-flop S3 and resetting counter 55.
The assignment logic embodiment of FIGS. 7A and 78 may be associated with only a small number of tone generators (twelve, in the example previously given), the exact number being selected in view of the cost limitations and the likely maximum number of keys that normally may be actuated simultaneously. In that case, each tone generator must supply every desired frequency corresponding to every note in every octave that may be played on the electronic organ.
FIG. 8A illustrates, in block diagrammatic form, an example of a suitable tone generator for generating the frequencies required for the notes selected on the organ keyboards. Appropriate frequencies are produced by properly addressing a memory unit containing amplitude samples of the desired waveform obtained at uniformly spaced points in time. Since the sample points are uniformly spaced in time, rather than uniformly spaced on the basis that an integral number of samples be present per cycle for each note frequency, the phase angle between sample points varies according to the frequency of the note to be generated. In a broader sense, the tone generator system of FIG. 8A demonstrates the teachings of the present invention with regard to addressing a memory unit at selectively controlled rates.
In implementing the memory addressing system of the present invention, the keyboard counter 1 is preferably provided with a note or key counter section 2 having at least one additional normally unused count that is to precede the initial count representing the sequence of keys and notes associated therewith. This redudant count, which is readily provided by merely employing a counter of greater capacity than is needed to handle the minimum count, is utilized to provide a start pulse which precedes the count that occurs each time the keyboard counter is reset to zero. Such a start pulse in the keyboard pulse train may, for example, be assigned to an imaginary key approximately two octaves below the lowest note in each manual. Thus, this start pulse is the first pulse in the scan, for the illustrative example of scanning from low frequencies to high frequencies on each keyboard, and occurs automatically with reset of the counter 1. The start pulse is applied to a flip-flop 100 for a purpose which will be explained presently. In addition the zero count, or count designating the reset, of octave section 3 of keyboard counter is supplied to the other input terminal of flip-flop 100. A memory unit 101, which is to be addressed at any of a number of selectively controlled rates, is preferably a read-only memory containing the digital amplitude values at predetermined sample points of a single cycle of the comlex periodic waveform to be produced for all note frequencies. That is to say, the same complex periodic waveform is to be reproduced for each note played, the only difference being that the phase angle between sample points stored in memory 101 will differ according to the frequency at which the complex waveform is reproduced.
Before proceeding with a description of the system of FIG. 8A and its operation, concurrent reference is made to FIG. 9 illustrating a typical complex waveshape of the type that might be produced by a pipe organ. The waveshape shown in FIG. 9 has been sampled at a multiplicity of points, shown as vertical lines in the Figure, to obtain the amplitude data to be stored in memory unit 101. It is only these uniformly spaced samples of amplitude that are stored in the memory and these may be stored in absolute form or in incremental form. In the former case, the data accessed is the actual amplitude of the output waveform at the respective sample point (i.e., with respect to a zero level at the abscissa). In the case of incremental amplitude information, however, the amplitude at each sample point as stored in memory 101 is simply the difference in amplitude between the amplitude of the present sample .and the amplitude of the immediately preceding sample. Each of the amplitude samples stored in the memory preferably comprises a digital word of approximately seven or eight bits.
The system for addressing memory 101 includes a storage register 102 which when reset contains a number representing the phase angle between sample points for the lowest note frequency to be produced by the tone generator. The storage register 102 is connected in a recirculating loop 103 which includes a multiplier 104 and a gate 105. The purpose of the multiplier is to successively multiply the contents of the storage register by the twelfth root of two (i.e., 2"") for computation of the phase angles between sample points of the complex waveform stored in memory 101 for every note frequency in the entire range of frequencies capable of being generated by the organ. This follows from the fact that in the equal interval, or even temperament, musical scale the note frequencies differ from one another by 2 The required computation may be performed in either a serial or parallel arrangement. For example, the storage register may be l2-bits long, and for serial operation, may recirculate once each 12 bit times. In such a case, the multiplier 104 is specifically constructed and arranged for serial operation. The keyboard counter octave section 3 (FIG. 1) advances once each twelve bit times, and hence, the storage register recirculates once each count of the octave section counter.
The computation of phase angle need not be performed in a serial format, however. Referring to FIG. 88, a parallel arrangement is shown in which the storage register 102 is connected to a scaling circuit 120 which, in turn, is coupled to an adder 121 in the recirculating loop 103. The twelfth root of two is approximately equal to 1.000011110011], base 2, which is equivalent to (1 2 -2 +2 2 The scaling circuit 120 is simply a set of multipliers. The adder 121 is preferably a cascaded network of parallel two input adders adapted to receive the outputs of the sealers. The phase angle number constituting the result of the addition is then recirculated back to the storage register 102.
Returning now to FIG. 8A, flip-flop is reset upon application of zero count of the octave section counter thereto, and the reset output of the flip-flop also serves to reset the storage register 102. Upon application of the start pulse of the multiplexed signal to the flipflop, the latter is switched to remove the register reset and to open the gate 105a in recirculating loop 103, thereby allowing the register contents to be multiplied by 2 and re-stored in the register.
The phase angle number which is thereby calculated with each advance of the keyboard count, and which represents a different phase angle between amplitude samples of the waveform stored in memory 101 for each different frequency, is always available when a note generator is captured and is assigned to generate a particular note frequency. When the modulo 384 counter 55 in the assignment logic associated with the captured note generator is reset to zero, the phase angle number available from the storage register 102, which is the correct phase angle for the selected note, because of the synchronization between the phase angle calculation and the keyboard count, is read into a phase angle register 108, and this occurs each time that modulo 384 counter 55 goes to zero. To that end, the zero count of counter 55 is applied to a flip-flop 105 (e.g., a one-shot) which is normally set to prevent passage of the phase angle number through an associated gate 106, but which is reset to open the gate 106 to permit passage of the phase angle number therethrough to the phase angle register 108 when the flipflop 105 is reset by the zero count of counter 55.
Quite clearly, the overall phase angle calculator and the read-only memory 101 may be shared by all of the tone generator 28. Each tone generator is addressed individually in the sequence of addressing all tone generators. For that reason, an auxiliary sampling clock (not shown) may be utilized which comprises a clock rate, provided by the master sampling clock, successive clock pulses of which are directed to the series of tone generators. The sampling clock addressed to a given tone generator is thus at a rate comprising the pulse repetition rate of the master sampling clock divided by the number of tone generators provided in the system. Furthermore, since the same read-only memory may be addressed by all of the tone generators, an accumulator 104a associated with the memory may be a composite structure associated with appropriate gating circuitry related to each tone generator for accumulating the information read from memory 101 in response to accessing thereof by a given tone generator.
Once each sampling clock time, as determined by the auxiliary sampling clock source controlled by the master clock, the phase angle value stored in the respective phase angle register 108 is added to the previously stored value in a sample point address register 109. An address decoder 110 decodes preselected bit positions of the count established in register 109 to effect addressing of memory unit 101. It is important to note that during addressing of memory 101, it is the rate at which the value of the sample point address register 109 increases, and not the absolute value of its contents, which is significant in the control of the rate of readout of the memory 101, and thus in the control of the frequency of the note produced by the given tone generator.
In this manner, once each clock time the phase angle number, comprising a digital binary word, is added to the sample point address register value and correspondingly, for each such clock time, the amplitude data in the memory location corresponding to the sample point address then contained in register 109 (as de 1 coded bydecoder 110) is accessed. As a practical manner, only a relatively small, finite set of amplitudes can I be stored in memory 101 because of practical limitations on its capacity, and thus only a finite number of addresses is available. Furthermore, each register must "be of a finite, practical length. In particular, the length of each register must be determined by the accuracy with which the frequency of the note is to be generated. The frequency actually produced is precisely the value of the phase angle multiplied by the clock rate at which the contents of the phase angle register are supplied to the address register 109. Thus, as the phase angle corresponding to the specific frequency changes, when a different note is selected, the rate at which the memory unit 101 is addressed also changes. In particular, it will be observed that the sample point address register 109 is incremented by the value of the phase angle number at each auxiliary clock time. That is to say, once each clock time, the phase angle number is added to the sample point address register. Only a relatively small number of bits in the region of least significance of the address register contents are used to designate the sample point addressed in memory 101 and these bits are arranged to be incremented at a rate which depends upon the phase angle number. Accordingly, for small phase angle numbers, no new address may be specified for several increases in the address-identifying number. At the uppermost note frequency, on the other hand, a sample point address in the memory is identified, and the memory is addressed for retrieval of the data contained in the specified location, for each increment of the address register dictated by the phase angle number. For lower frequencies, the incrementing of the sample point address register is such that new addresses are identified only after a corresponding number of repetitions of the phase angle number at the fixed clock frequency. In the embodiment of FIG. 8A, the same effect is achieved by use of an address decoder 110. The digital words thus read from memory unit 101 are supplied to an accumulator 1042 which provides a digital representation of the waveform at selected sample points over a cycle of the waveform and at a frequency corresponding to the note to be reproduced. As above described, this digital waveform representation may itself be operated upon for waveshape control (for exam ple, attack and decay) and is subsequently supplied to a digital-to-analog converter for producing an analog signal suiable for driving the acoustical output means, such as audio speakers, of the organ.
What is claimed is:
1. An electronic organ including a keyboard having a plurality of keys respectively associated with notes of themusical scale, said keys being operable, when actuated, to develop signals for calling forth respectively associated notes as audible tones of the desired note frequencies from said organ, and a tone generator said tone generator comprising:
a memory storing amplitude samples of a waveform to be reproduced at the desired note frequencies, said amplitude samples of the waveform being taken at points uniformly spaced in time over a cycle thereof,
clock means establishing a fixed rate of accessing amplitude samples of said waveform from said memory,
means for developing a succession of phase angle numbers respectively corresponding in value to the frequencies of the notes of the musical scale available to be called forth selectively by actuation of corresponding ones of the keys, and 7 means responsive to a signal developed by the actua- 2. An electronic organ as recited in claim 1 wherein said number developing means includes:
means for establishing a first number corresponding to a lowest frequency note available to be reproduced, and
means for successively increasing the first and each successive number by a common factor to develop a set of numbers differing respectively in succession by the common factor, thereby to correspond to successive note frequencies of the musical scale, for all note frequencies to be synthesized.
3. An electronic organ as recited in claim 2 wherein said responsive means includes:
a note frequency number register for storing the numbers corresponding to the selected note, and an address register for adding the stored, corresponding number to the contents of said address register at the fixed frequency of said fixed frequency generator, the content of said address register thereby increasing at a rate corresponding to the fixed frequency and the selected number and establishing the rate of addressing said memory. 4. A tone generator for synthesizing frequencies of the notes of the musical scale in an electronic musical instrument, the instrument including means for selecting the notes to be synthesized, said generator comprism nemory means for storing amplitude values of a waveform to be reproduced at the desired note frequencies, said amplitude values of the waveform being taken at uniformly spaced points in time over one cycle of the waveform,
a fixed frequency generator,
means for developing a succession of numbers respectively corresponding in value to the frequencies of the notes of the musical scale available for selection, and
means responsive to the selection of a particular note to be synthesized by said generator for responding to the number developed by said developing means for that note frequency and the fixed frequency of said fixed frequency generator, thereby to address said memory at a rate corresponding to the frequency of said generator and the number for the corresponding note frequency, thereby cyclically to read out the stored amplitude values from said memory for synthesizing the selected note frequency.
5. An electronic organ as recited in claim 4 wherein said number developing means includes:
means for establishing a first number corresponding to a lowest frequency note available to be reproduced, and
means for successively increasing the first and each successive number by a common factor to develop a set of numbers differing respectively in succession by the common factor, thereby to correspond to successive note frequencies of the musical scale, for all note frequencies to be synthesized.
6. An electronic organ as recited in claim 5 wherein said responsive means includes:
a note frequency number register for storing the establishing the rate of addressing said memory.
Claims (6)
1. An electronic organ including a keyboard having a plurality of keys respectively associated with notes of the musical scale, said keys being operable, when actuated, to develop signals for calling forth respectively associated notes as audible tones of the desired note frequencies from said organ, and a tone generator said tone generator comprising: a memory storing amplitude samples of a waveform to be reproduced at the desired note frequencies, said amplitude samples of the waveform being taken at points uniformly spaced in time over a cycle thereof, clock means establishing a fixed rate of accessing amplitude samples of said waveform from said memory, means for developing a succession of phase angle numbers respectively corresponding in value to the frequencies of the notes of the musical scale available to be called forth selectively by actuation of corresponding ones of the keys, and means responsive to a signal developed by the actuation of any one of said keys for selecting the corresponding phase angle number, and responsive to said clock means for addressing the sample points to be accessed from said memory at a rate in proportion to the corresponding, selected phase angle for the note frequency associated with each actuated key, to cyclically reproduce the stored waveform at a frequency corresponding to the note frequency associated with the respective, actuated key.
2. An electronic organ as recited in claim 1 wherein said number developing means includes: means for establishing a first number corresponding to a lowest frequency note available to be reproduced, and means for successively increasing the first and each successive number by a common factor to develop a set of numbers differing respectively in succession by the common factor, thereby to correspond to successive note frequencies of the musical scale, for all note frequencies to be synthesized.
3. An electronic organ as recited in claim 2 wherein said responsive means includes: a note freqUency number register for storing the numbers corresponding to the selected note, and an address register for adding the stored, corresponding number to the contents of said address register at the fixed frequency of said fixed frequency generator, the content of said address register thereby increasing at a rate corresponding to the fixed frequency and the selected number and establishing the rate of addressing said memory.
4. A tone generator for synthesizing frequencies of the notes of the musical scale in an electronic musical instrument, the instrument including means for selecting the notes to be synthesized, said generator comprising: memory means for storing amplitude values of a waveform to be reproduced at the desired note frequencies, said amplitude values of the waveform being taken at uniformly spaced points in time over one cycle of the waveform, a fixed frequency generator, means for developing a succession of numbers respectively corresponding in value to the frequencies of the notes of the musical scale available for selection, and means responsive to the selection of a particular note to be synthesized by said generator for responding to the number developed by said developing means for that note frequency and the fixed frequency of said fixed frequency generator, thereby to address said memory at a rate corresponding to the frequency of said generator and the number for the corresponding note frequency, thereby cyclically to read out the stored amplitude values from said memory for synthesizing the selected note frequency.
5. An electronic organ as recited in claim 4 wherein said number developing means includes: means for establishing a first number corresponding to a lowest frequency note available to be reproduced, and means for successively increasing the first and each successive number by a common factor to develop a set of numbers differing respectively in succession by the common factor, thereby to correspond to successive note frequencies of the musical scale, for all note frequencies to be synthesized.
6. An electronic organ as recited in claim 5 wherein said responsive means includes: a note frequency number register for storing the numbers corresponding to the selected note, and an address register for adding the stored, corresponding number to the contents of said address register at the fixed frequency of said fixed frequency generator, the content of said address register thereby increasing at a rate corresponding to the fixed frequency and the selected number and establishing the rate of addressing said memory.
Applications Claiming Priority (12)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US87259869A | 1969-10-30 | 1969-10-30 | |
US87259769A | 1969-10-30 | 1969-10-30 | |
US87260069A | 1969-10-30 | 1969-10-30 | |
US87259969A | 1969-10-30 | 1969-10-30 | |
US87517869A | 1969-11-10 | 1969-11-10 | |
US17099271A | 1971-08-11 | 1971-08-11 | |
GB3994671 | 1971-08-25 | ||
AU32776/71A AU449757B2 (en) | 1969-10-30 | 1971-08-26 | Method and apparatus for addressing a memory at selectively controlled rates |
NLAANVRAGE7112290,A NL174997C (en) | 1969-10-30 | 1971-09-07 | DEVICE FOR ADDRESSING A MEMORY WITH SELECTIVELY CONTROLLED SPEEDS. |
FR7133790A FR2153149B1 (en) | 1969-10-30 | 1971-09-20 | |
DE2149104A DE2149104C3 (en) | 1969-10-30 | 1971-09-28 | Process for generating electrical vibrations |
CH1505971A CH559956A5 (en) | 1969-10-30 | 1971-10-15 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3743755A true US3743755A (en) | 1973-07-03 |
Family
ID=27582831
Family Applications (6)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US872597A Expired - Lifetime US3610799A (en) | 1969-10-30 | 1969-10-30 | Multiplexing system for selection of notes and voices in an electronic musical instrument |
US872598A Expired - Lifetime US3610805A (en) | 1969-10-30 | 1969-10-30 | Attack and decay system for a digital electronic organ |
US872600A Expired - Lifetime US3610806A (en) | 1969-10-30 | 1969-10-30 | Adaptive sustain system for digital electronic organ |
US872599A Expired - Lifetime US3610800A (en) | 1969-10-30 | 1969-10-30 | Digital electronic keyboard instrument with automatic transposition |
US875178A Expired - Lifetime US3639913A (en) | 1969-10-30 | 1969-11-10 | Method and apparatus for addressing a memory at selectively controlled rates |
US00170992A Expired - Lifetime US3743755A (en) | 1969-10-30 | 1971-08-11 | Method and apparatus for addressing a memory at selectively controlled rates |
Family Applications Before (5)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US872597A Expired - Lifetime US3610799A (en) | 1969-10-30 | 1969-10-30 | Multiplexing system for selection of notes and voices in an electronic musical instrument |
US872598A Expired - Lifetime US3610805A (en) | 1969-10-30 | 1969-10-30 | Attack and decay system for a digital electronic organ |
US872600A Expired - Lifetime US3610806A (en) | 1969-10-30 | 1969-10-30 | Adaptive sustain system for digital electronic organ |
US872599A Expired - Lifetime US3610800A (en) | 1969-10-30 | 1969-10-30 | Digital electronic keyboard instrument with automatic transposition |
US875178A Expired - Lifetime US3639913A (en) | 1969-10-30 | 1969-11-10 | Method and apparatus for addressing a memory at selectively controlled rates |
Country Status (8)
Country | Link |
---|---|
US (6) | US3610799A (en) |
AU (1) | AU449757B2 (en) |
BE (1) | BE772689A (en) |
CH (1) | CH559956A5 (en) |
DE (1) | DE2149104C3 (en) |
FR (1) | FR2153149B1 (en) |
GB (1) | GB1317385A (en) |
NL (1) | NL174997C (en) |
Cited By (48)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3809790A (en) * | 1973-01-31 | 1974-05-07 | Nippon Musical Instruments Mfg | Implementation of combined footage stops in a computor organ |
US3809786A (en) * | 1972-02-14 | 1974-05-07 | Deutsch Res Lab | Computor organ |
US3809789A (en) * | 1972-12-13 | 1974-05-07 | Nippon Musical Instruments Mfg | Computor organ using harmonic limiting |
US3809792A (en) * | 1973-01-05 | 1974-05-07 | Nippon Musical Instruments Mfg | Production of celeste in a computor organ |
US3809788A (en) * | 1972-10-17 | 1974-05-07 | Nippon Musical Instruments Mfg | Computor organ using parallel processing |
US3842184A (en) * | 1973-05-07 | 1974-10-15 | Chicago Musical Instr Co | Musical instrument having automatic arpeggio system |
US3854365A (en) * | 1971-07-31 | 1974-12-17 | Nippon Musical Instruments Mfg | Electronic musical instruments reading memorized waveforms for tone generation and tone control |
US3878750A (en) * | 1973-11-21 | 1975-04-22 | Charles A Kapps | Programmable music synthesizer |
US3882751A (en) * | 1972-12-14 | 1975-05-13 | Nippon Musical Instruments Mfg | Electronic musical instrument employing waveshape memories |
US3894463A (en) * | 1973-11-26 | 1975-07-15 | Canadian Patents Dev | Digital tone generator |
US3903775A (en) * | 1973-03-08 | 1975-09-09 | Nippon Musical Instruments Mfg | Electronic musical instrument |
US3913442A (en) * | 1974-05-16 | 1975-10-21 | Nippon Musical Instruments Mfg | Voicing for a computor organ |
US3915047A (en) * | 1974-01-02 | 1975-10-28 | Ibm | Apparatus for attaching a musical instrument to a computer |
US3916750A (en) * | 1972-02-04 | 1975-11-04 | Baldwin Co D H | Electronic organ employing time position multiplexed signals |
DE2524062A1 (en) * | 1974-05-31 | 1975-12-11 | Nippon Musical Instruments Mfg | ELECTRONIC MUSICAL INSTRUMENT WITH VIBRATO GENERATION |
DE2523881A1 (en) * | 1974-05-31 | 1975-12-11 | Nippon Musical Instruments Mfg | ELECTRONIC MUSICAL INSTRUMENT WITH NOISE SUPPLY EFFECT |
US3929053A (en) * | 1974-04-29 | 1975-12-30 | Nippon Musical Instruments Mfg | Production of glide and portamento in an electronic musical instrument |
JPS5116015A (en) * | 1974-07-31 | 1976-02-09 | Matsushita Electric Ind Co Ltd | |
US3951028A (en) * | 1974-10-23 | 1976-04-20 | Kimball International, Inc. | Electronic organ and method of operation |
US3952623A (en) * | 1974-11-12 | 1976-04-27 | Nippon Gakki Seizo Kabushiki Kaisha | Digital timing system for an electronic musical instrument |
US3955460A (en) * | 1975-03-26 | 1976-05-11 | C. G. Conn Ltd. | Electronic musical instrument employing digital multiplexed signals |
US3978755A (en) * | 1974-04-23 | 1976-09-07 | Allen Organ Company | Frequency separator for digital musical instrument chorus effect |
US3982461A (en) * | 1974-06-06 | 1976-09-28 | Kabushiki Kaisha Kawai Gakki Seisakusho | Musical-tone signal forming apparatus for electronic musical instrument |
US4030395A (en) * | 1974-06-06 | 1977-06-21 | Kabushiki Kaisha Kawai Gakki Seisakusho | Musical-tone signal forming apparatus for an electronic musical instrument |
US4041825A (en) * | 1974-10-15 | 1977-08-16 | Pascetta Armand N | Keyboard assignment system for a polyphonic electronic musical instrument |
US4046047A (en) * | 1975-08-11 | 1977-09-06 | Warwick Electronics Inc. | Note selector circuit for electronic musical instrument |
DE2711511A1 (en) * | 1976-03-16 | 1977-09-22 | Christian Deforeit | POLYPHONIC ELECTRONIC MUSICAL INSTRUMENT |
US4114496A (en) * | 1977-01-10 | 1978-09-19 | Kawai Musical Instrument Mfg. Co., Ltd. | Note frequency generator for a polyphonic tone synthesizer |
US4148241A (en) * | 1975-08-26 | 1979-04-10 | Norlin Music, Inc. | Electronic musical instrument with means for automatically generating chords and harmony |
US4177706A (en) * | 1976-09-08 | 1979-12-11 | Greenberger Alan J | Digital real time music synthesizer |
US4192007A (en) * | 1978-05-30 | 1980-03-04 | Lorain Products Corporation | Programmable ringing generator |
US4202234A (en) * | 1976-04-28 | 1980-05-13 | National Research Development Corporation | Digital generator for musical notes |
US4218948A (en) * | 1977-12-27 | 1980-08-26 | Nippon Gakki Seizo Kabushiki Kaisha | Electronic musical instrument of key code processing type |
US4242936A (en) * | 1979-09-14 | 1981-01-06 | Norlin Industries, Inc. | Automatic rhythm generator |
US4256003A (en) * | 1979-07-19 | 1981-03-17 | Kawai Musical Instrument Mfg. Co., Ltd. | Note frequency generator for an electronic musical instrument |
DE3023580A1 (en) * | 1980-06-24 | 1982-01-07 | Matth. Hohner Ag, 7218 Trossingen | METHOD FOR PHASE SYNCHRONIZING DIGITALLY SYNTHETIZED TOOLS OF A MUSICAL INSTRUMENT, AND CIRCUIT ARRANGEMENT FOR IMPLEMENTING THE METHOD |
US4338674A (en) * | 1979-04-05 | 1982-07-06 | Sony Corporation | Digital waveform generating apparatus |
US4338844A (en) * | 1979-02-17 | 1982-07-13 | Kabushiki Kaisha Kawai Gakki Seisakusho | Tone source circuit for electronic musical instruments |
US4409876A (en) * | 1980-12-01 | 1983-10-18 | Nippon Gakki Seizo Kabushiki Kaisha | Electronic musical instrument forming tone waveforms |
US4463647A (en) * | 1976-08-16 | 1984-08-07 | Melville Clark, Jr. | Musical instrument |
US4495846A (en) * | 1977-11-14 | 1985-01-29 | Williams S Keith | Electronic musical instrument |
US4513365A (en) * | 1982-02-11 | 1985-04-23 | Reinhard Franz | Function selector |
US4561337A (en) * | 1983-06-08 | 1985-12-31 | Nippon Gakki Seizo Kabushiki Kaisha | Digital electronic musical instrument of pitch synchronous sampling type |
JPH0239099A (en) * | 1988-07-28 | 1990-02-08 | Ricoh Co Ltd | Musical sound generator |
US4936179A (en) * | 1986-10-04 | 1990-06-26 | Kabushiki Kaisha Kawai Gakki Seisakusho | Electronic musical instrument |
US5457455A (en) * | 1992-09-22 | 1995-10-10 | Rockwell International Corporation | Real time keyboard scanner |
US6326537B1 (en) * | 1995-09-29 | 2001-12-04 | Yamaha Corporation | Method and apparatus for generating musical tone waveforms by user input of sample waveform frequency |
US6410838B1 (en) * | 1999-12-16 | 2002-06-25 | Yamaha Corporation | Musical sound signal synthesizer and method for synthesizing musical sound signals using nonlinear transformer |
Families Citing this family (221)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3610799A (en) * | 1969-10-30 | 1971-10-05 | North American Rockwell | Multiplexing system for selection of notes and voices in an electronic musical instrument |
US3733593A (en) * | 1970-10-09 | 1973-05-15 | Rockwell International Corp | Capture combination system |
US3696201A (en) * | 1970-11-12 | 1972-10-03 | Wurlitzer Co | Digital organ system |
JPS5040932B1 (en) * | 1970-12-26 | 1975-12-27 | ||
US3752898A (en) * | 1971-04-05 | 1973-08-14 | Kawai Musical Instr Mfg Co | Electronic musical instrument |
JPS5117414B1 (en) * | 1971-05-11 | 1976-06-02 | ||
US3969969A (en) * | 1971-06-01 | 1976-07-20 | Melville Clark, Jr. | Musical instrument with means for scanning keys |
US3969968A (en) * | 1971-06-01 | 1976-07-20 | Melville Clark, Jr. | Musical instrument with means for scanning keys |
US3968717A (en) * | 1971-06-01 | 1976-07-13 | Melville Clark, Jr. | Musical instrument with means for scanning keys |
US4365533A (en) * | 1971-06-01 | 1982-12-28 | Melville Clark, Jr. | Musical instrument |
US3968716A (en) * | 1971-06-01 | 1976-07-13 | Melville Clark, Jr. | Musical instrument with means for scanning keys |
USH1970H1 (en) * | 1971-07-19 | 2001-06-05 | Texas Instruments Incorporated | Variable function programmed system |
US3743756A (en) * | 1971-08-12 | 1973-07-03 | Philips Corp | Method of producing tones of a preferably substantially equal-tempered scale |
US3819844A (en) * | 1971-11-18 | 1974-06-25 | Nippon Musical Instruments Mfg | Electronic musical instrument keying system with envelope sample memorizing voltage dividers |
US3763364A (en) * | 1971-11-26 | 1973-10-02 | North American Rockwell | Apparatus for storing and reading out periodic waveforms |
US3794748A (en) * | 1971-12-06 | 1974-02-26 | North American Rockwell | Apparatus and method for frequency modulation for sampled amplitude signal generating system |
US3755608A (en) * | 1971-12-06 | 1973-08-28 | North American Rockwell | Apparatus and method for selectively alterable voicing in an electrical instrument |
US3740450A (en) * | 1971-12-06 | 1973-06-19 | North American Rockwell | Apparatus and method for simulating chiff in a sampled amplitude electronic organ |
US3811003A (en) * | 1971-12-13 | 1974-05-14 | Baldwin Co D H | Rhythm accompaniment system |
US3859884A (en) * | 1971-12-15 | 1975-01-14 | Dillon Ross Grable | Tone generator |
US3844379A (en) * | 1971-12-30 | 1974-10-29 | Nippon Musical Instruments Mfg | Electronic musical instrument with key coding in a key address memory |
JPS5115972B2 (en) * | 1972-02-22 | 1976-05-20 | ||
JPS5115973B2 (en) * | 1972-02-22 | 1976-05-20 | ||
US3746773A (en) * | 1972-02-04 | 1973-07-17 | Baldwin Co D H | Electronic organ employing time position multiplexed signals |
AU459101B2 (en) * | 1972-02-10 | 1975-03-20 | Matsushita Electric Industrial Co., Ltd. | Samplling modulation system for an electronic misical instrument |
US3971282A (en) * | 1972-04-20 | 1976-07-27 | Kabushiki Kaisha Kawai Gakki Seisakusho | Electronic musical instrument capable of transposition |
JPS5121564B2 (en) * | 1972-04-20 | 1976-07-03 | ||
JPS5121565B2 (en) * | 1972-04-20 | 1976-07-03 | ||
US3749837A (en) * | 1972-05-02 | 1973-07-31 | J Doughty | Electronic musical tone modifier for musical instruments |
USRE28999E (en) * | 1972-06-16 | 1976-10-12 | C. G. Conn, Ltd. | Automatic rhythm system providing drum break |
US3764722A (en) * | 1972-06-16 | 1973-10-09 | Conn Ltd C G | Automatic rhythm system providing drum break |
US3789719A (en) * | 1972-08-28 | 1974-02-05 | J Maillet | Tape activated piano and organ player |
US3810106A (en) * | 1972-10-05 | 1974-05-07 | Apm Corp | System for storing tone patterns for audible retrieval |
JPS5217411B2 (en) * | 1972-10-12 | 1977-05-16 | ||
US3842182A (en) * | 1972-10-17 | 1974-10-15 | Baldwin Co D H | Arpeggio system |
US3809884A (en) * | 1972-11-15 | 1974-05-07 | Honeywell Inf Systems | Apparatus and method for a variable memory cycle in a data processing unit |
JPS4974924A (en) * | 1972-11-17 | 1974-07-19 | ||
JPS5231732B2 (en) * | 1972-12-14 | 1977-08-17 | ||
JPS5231729B2 (en) * | 1972-12-14 | 1977-08-17 | ||
US4011784A (en) * | 1972-12-19 | 1977-03-15 | Pioneer Electronic Corporation | Transposition apparatus for an electronic musical instrument |
JPS4984635A (en) * | 1972-12-20 | 1974-08-14 | ||
US3902397A (en) * | 1973-01-12 | 1975-09-02 | Chicago Musical Instr Co | Electronic musical instrument with variable amplitude time encoded pulses |
GB1435363A (en) * | 1973-01-12 | 1976-05-12 | Chicago Musical Instr Co | Electronic musical instruments |
US3828643A (en) * | 1973-02-20 | 1974-08-13 | Chicago Musical Instr Co | Scanner for electronic musical instrument |
JPS566559B2 (en) * | 1973-03-10 | 1981-02-12 | ||
US4119005A (en) * | 1973-03-10 | 1978-10-10 | Nippon Gakki Seizo Kabushiki Kaisha | System for generating tone source waveshapes |
JPS5735477B2 (en) * | 1973-03-10 | 1982-07-29 | ||
US3885489A (en) * | 1973-03-14 | 1975-05-27 | Kenju Sangyo Kabushiki Kaisha | Electronic musical instrument having keyboards |
JPS568360B2 (en) * | 1973-04-14 | 1981-02-23 | ||
JPS5840199B2 (en) * | 1973-04-14 | 1983-09-03 | ヤマハ株式会社 | Denshigatsuki |
US3800060A (en) * | 1973-04-27 | 1974-03-26 | J Hallman | Keynote selector apparatus for electronic organs |
US3839592A (en) * | 1973-04-30 | 1974-10-01 | A Freeman | Plural mode automatic bass system with pedal sustain |
US3930429A (en) * | 1973-06-08 | 1976-01-06 | Arp Instruments, Inc. | Digital music synthesizer |
JPS6012638B2 (en) * | 1973-06-12 | 1985-04-02 | ヤマハ株式会社 | Automatic performance device for electronic musical instruments |
US3955459A (en) * | 1973-06-12 | 1976-05-11 | Nippon Gakki Seizo Kabushiki Kaisha | Electronic musical instrument |
JPS5037422A (en) * | 1973-08-03 | 1975-04-08 | ||
US3899951A (en) * | 1973-08-09 | 1975-08-19 | Nippon Musical Instruments Mfg | Key switch scanning and encoding system |
NL164149C (en) * | 1973-10-06 | 1980-11-17 | Philips Nv | CIRCUIT FOR TRANSPOSING AND FORMING AGREEMENTS. |
US3902395A (en) * | 1973-10-11 | 1975-09-02 | William L Avant | Stringed musical instrument with electronic time division multiplexing circuitry |
US3929051A (en) * | 1973-10-23 | 1975-12-30 | Chicago Musical Instr Co | Multiplex harmony generator |
JPS5081527A (en) * | 1973-11-20 | 1975-07-02 | ||
JPS5084230A (en) * | 1973-11-24 | 1975-07-08 | ||
US3871247A (en) * | 1973-12-12 | 1975-03-18 | Arthur R Bonham | Musical instrument employing time division multiplexing techniques to control a second musical instrument |
US3926088A (en) * | 1974-01-02 | 1975-12-16 | Ibm | Apparatus for processing music as data |
US3910150A (en) * | 1974-01-11 | 1975-10-07 | Nippon Musical Instruments Mfg | Implementation of octave repeat in a computor organ |
US3953835A (en) * | 1974-01-18 | 1976-04-27 | Honeywell Information Systems, Inc. | Method and apparatus for adapting a data processing port to receive and transmit different frequency signals |
US3889568A (en) * | 1974-01-31 | 1975-06-17 | Pioneer Electric Corp | Automatic chord performance apparatus for a chord organ |
US3905267A (en) * | 1974-02-04 | 1975-09-16 | Raymond A Vincent | Electronic player piano with record and playback feature |
US3898905A (en) * | 1974-03-04 | 1975-08-12 | Hammond Corp | Monophonic electronic musical instrument |
US3908504A (en) * | 1974-04-19 | 1975-09-30 | Nippon Musical Instruments Mfg | Harmonic modulation and loudness scaling in a computer organ |
US3854366A (en) * | 1974-04-26 | 1974-12-17 | Nippon Musical Instruments Mfg | Automatic arpeggio |
CA1041325A (en) * | 1974-06-03 | 1978-10-31 | Wurlitzer Company (The) | Electronic musical instrument using integrated circuit components |
JPS50156418A (en) * | 1974-06-06 | 1975-12-17 | ||
US3956960A (en) * | 1974-07-25 | 1976-05-18 | Nippon Gakki Seizo Kabushiki Kaisha | Formant filtering in a computor organ |
US3937115A (en) * | 1974-08-01 | 1976-02-10 | The Wurlitzer Company | Electronic piano circuit arrangement |
US4041826A (en) * | 1974-08-07 | 1977-08-16 | Nippon Gakki Seizo Kabushiki Kaisha | Electronic musical instrument |
JPS5615519B2 (en) * | 1974-08-12 | 1981-04-10 | ||
US3943811A (en) * | 1974-08-12 | 1976-03-16 | Coles Donald K | Keyboard type musical instrument |
US4014238A (en) * | 1974-08-13 | 1977-03-29 | C.G. Conn, Ltd. | Tone signal waveform control network for musical instrument keying system |
US4134320A (en) * | 1974-08-19 | 1979-01-16 | Nippon Gakki Seizo Kabushiki Kaisha | Key assigner for use in electronic musical instrument |
US3875842A (en) * | 1974-08-23 | 1975-04-08 | Nat Semiconductor Corp | Multiplexing system for selection of notes in an electronic musical instrument |
US3943814A (en) * | 1974-08-26 | 1976-03-16 | Henry Wemekamp | Electric organ tone generating system |
GB1518951A (en) * | 1974-09-05 | 1978-07-26 | Nippon Musical Instruments Mfg | Key assigner |
US3973460A (en) * | 1974-09-18 | 1976-08-10 | Coles Donald K | Keyboard type musical instrument |
US3972259A (en) * | 1974-09-26 | 1976-08-03 | Nippon Gakki Seizo Kabushiki Kaisha | Production of pulse width modulation tonal effects in a computor organ |
US4083285A (en) * | 1974-09-27 | 1978-04-11 | Nippon Gakki Seizo Kabushiki Kaisha | Electronic musical instrument |
FR2286552A1 (en) * | 1974-09-30 | 1976-04-23 | Roche Bernard | DIGITAL GENERATOR OF MULTI-FREQUENCY CODE SIGNALS |
JPS5143121A (en) * | 1974-10-11 | 1976-04-13 | Nippon Musical Instruments Mfg | Denshigatsukino torankeetokairo |
US3990339A (en) * | 1974-10-23 | 1976-11-09 | Kimball International, Inc. | Electric organ and method of operation |
JPS5441497B2 (en) * | 1974-11-14 | 1979-12-08 | ||
JPS5194909A (en) * | 1974-11-15 | 1976-08-20 | ||
JPS5441498B2 (en) * | 1974-11-15 | 1979-12-08 | ||
JPS5441499B2 (en) * | 1974-11-18 | 1979-12-08 | ||
JPS5158322A (en) * | 1974-11-18 | 1976-05-21 | Matsushita Electric Ind Co Ltd | |
JPS5158320A (en) * | 1974-11-18 | 1976-05-21 | Matsushita Electric Ind Co Ltd | |
JPS5158928A (en) * | 1974-11-19 | 1976-05-22 | Matsushita Electric Ind Co Ltd | |
JPS5158929A (en) * | 1974-11-19 | 1976-05-22 | Matsushita Electric Ind Co Ltd | |
JPS5158927A (en) * | 1974-11-19 | 1976-05-22 | Matsushita Electric Ind Co Ltd | |
JPS5158932A (en) * | 1974-11-20 | 1976-05-22 | Matsushita Electric Ind Co Ltd | |
JPS5158938A (en) * | 1974-11-20 | 1976-05-22 | Matsushita Electric Ind Co Ltd | |
JPS5158931A (en) * | 1974-11-20 | 1976-05-22 | Matsushita Electric Ind Co Ltd | |
JPS5160517A (en) * | 1974-11-22 | 1976-05-26 | Matsushita Electric Ind Co Ltd | |
JPS5160515A (en) * | 1974-11-22 | 1976-05-26 | Matsushita Electric Ind Co Ltd | |
US3986423A (en) * | 1974-12-11 | 1976-10-19 | Oberheim Electronics Inc. | Polyphonic music synthesizer |
JPS5172319A (en) * | 1974-12-18 | 1976-06-23 | Nippon Musical Instruments Mfg | |
US4108038A (en) * | 1975-04-04 | 1978-08-22 | Nippon Gakki Seizo Kabushiki Kaisha | Time shared tone keying system in electronic musical instrument |
GB1543958A (en) * | 1975-04-23 | 1979-04-11 | Nippon Musical Instruments Mfg | Electronic musical instrument |
JPS51124415A (en) * | 1975-04-23 | 1976-10-29 | Nippon Gakki Seizo Kk | Electronic musical instrument |
US4133241A (en) * | 1975-05-27 | 1979-01-09 | Nippon Gakki Seizo Kabushiki Kaisha | Electronic musical instrument utilizing recursive algorithm |
US4058042A (en) * | 1975-06-20 | 1977-11-15 | D. H. Baldwin Company | Key transposing electronic organ |
GB1558280A (en) * | 1975-07-03 | 1979-12-19 | Nippon Musical Instruments Mfg | Electronic musical instrument |
US4108036A (en) * | 1975-07-31 | 1978-08-22 | Slaymaker Frank H | Method of and apparatus for electronically generating musical tones and the like |
US4031786A (en) * | 1975-08-11 | 1977-06-28 | Warwick Electronics Inc. | Tone selector circuit with multiplexed tone data transfer |
JPS5224517A (en) * | 1975-08-20 | 1977-02-24 | Nippon Gakki Seizo Kk | Channel processor |
JPS5224518A (en) * | 1975-08-20 | 1977-02-24 | Nippon Gakki Seizo Kk | Key switch detection processing unit |
USRE31931E (en) * | 1975-08-20 | 1985-07-02 | Nippon Gakki Seizo Kabushiki Kaisha | Channel processor |
JPS5917835B2 (en) * | 1975-08-20 | 1984-04-24 | ヤマハ株式会社 | Key-off judgment circuit in key switch device |
US4023454A (en) * | 1975-08-28 | 1977-05-17 | Kabushiki Kaisha Dawai Gakki Seisakusho | Tone source apparatus for an electronic musical instrument |
US4070943A (en) * | 1975-09-05 | 1978-01-31 | Faulkner Alfred H | Electronic organ keying system |
JPS5237028A (en) * | 1975-09-17 | 1977-03-22 | Nippon Gakki Seizo Kk | Electronical music instrument |
US4186636A (en) * | 1975-10-21 | 1980-02-05 | Thomas International Corporation | Digital chord generation for electronic musical instruments |
US4079650A (en) * | 1976-01-26 | 1978-03-21 | Deutsch Research Laboratories, Ltd. | ADSR envelope generator |
JPS52121313A (en) * | 1976-04-06 | 1977-10-12 | Nippon Gakki Seizo Kk | Electronic musical instrument |
US4178821A (en) * | 1976-07-14 | 1979-12-18 | M. Morell Packaging Co., Inc. | Control system for an electronic music synthesizer |
US4145946A (en) * | 1976-08-09 | 1979-03-27 | Kawai Musical Instrument Mfg. Co., Ltd. | Sustained repeat control digital polyphonic synthesizer |
US4108039A (en) * | 1976-08-09 | 1978-08-22 | Kawai Musical Instrument Mfg. Co., Ltd. | Switch selectable harmonic strength control for a tone synthesizer |
JPS589958B2 (en) * | 1976-09-29 | 1983-02-23 | ヤマハ株式会社 | Envelope generator for electronic musical instruments |
USRE30906E (en) * | 1976-10-08 | 1982-04-20 | Nippon Gakki Seizo Kabushiki Kaisha | Envelope generator |
JPS5812599B2 (en) * | 1976-10-08 | 1983-03-09 | ヤマハ株式会社 | Envelope generator for electronic musical instruments |
JPS5842479B2 (en) * | 1976-10-18 | 1983-09-20 | ヤマハ株式会社 | Wave generator for electronic musical instruments |
US4198889A (en) * | 1977-01-07 | 1980-04-22 | Groeschel Charles R | Modulation circuitry for use in a music encoding system |
US4126070A (en) * | 1977-01-31 | 1978-11-21 | Hill Jeremy R | Keyboard musical instrument |
US4119006A (en) * | 1977-02-24 | 1978-10-10 | Allen Organ Company | Continuously variable attack and decay delay for an electronic musical instrument |
US4085643A (en) * | 1977-03-03 | 1978-04-25 | Nippon Gakki Seizo Kabushiki Kaisha | Truncated decay system |
JPS5319821A (en) * | 1977-03-28 | 1978-02-23 | Nippon Gakki Seizo Kk | Electronic musical instrument |
US4134321A (en) * | 1977-04-14 | 1979-01-16 | Allen Organ Company | Demultiplexing audio waveshape generator |
US4189970A (en) * | 1977-04-14 | 1980-02-26 | Allen Organ Company | Method and apparatus for achieving timbre modulation in an electronic musical instrument |
US4279185A (en) * | 1977-06-07 | 1981-07-21 | Alonso Sydney A | Electronic music sampling techniques |
US4177708A (en) * | 1977-06-17 | 1979-12-11 | Rochelle Pinz | Combined computer and recorder for musical sound reproduction |
US4240316A (en) * | 1977-06-17 | 1980-12-23 | Kabushiki Kaisha Kawai Gakki Seisakusho | Keyboard type electronic musical instrument |
JPS5316616A (en) * | 1977-06-24 | 1978-02-15 | Nippon Gakki Seizo Kk | Electronic musical instrument |
US4201109A (en) * | 1977-08-15 | 1980-05-06 | Kabushiki Kaisha Kawai Gakki Seisakusho | Envelope waveform generator for electronic musical instruments |
US4240317A (en) * | 1977-09-09 | 1980-12-23 | National Semiconductor Corporation | Electronic musical instrument |
US4186637A (en) * | 1977-09-22 | 1980-02-05 | Norlin Industries, Inc. | Tone generating system for electronic musical instrument |
US4282785A (en) * | 1977-10-17 | 1981-08-11 | Kabushiki Kaisha Kawai Gakki Seisakusho | Electronic musical instrument |
JPS5919355B2 (en) * | 1977-10-26 | 1984-05-04 | ヤマハ株式会社 | electronic musical instruments |
US4184403A (en) * | 1977-11-17 | 1980-01-22 | Allen Organ Company | Method and apparatus for introducing dynamic transient voices in an electronic musical instrument |
JPS5935037B2 (en) * | 1977-12-14 | 1984-08-25 | ヤマハ株式会社 | electronic musical instruments |
US4198890A (en) * | 1978-01-04 | 1980-04-22 | Alito Paul N | Keyboard system for musical instruments |
US4202239A (en) * | 1978-01-09 | 1980-05-13 | C. G. Conn, Ltd. | Tone generator keyer control system |
US4227432A (en) * | 1978-02-23 | 1980-10-14 | Marmon Company | Electronic musical instrument having multiplexed keying |
US4194426A (en) * | 1978-03-13 | 1980-03-25 | Kawai Musical Instrument Mfg. Co. Ltd. | Echo effect circuit for an electronic musical instrument |
DE2954066C2 (en) * | 1978-03-18 | 1985-09-26 | Casio Computer Co., Ltd., Tokio/Tokyo | Electronic musical instrument |
GB2017376B (en) * | 1978-03-18 | 1983-03-16 | Casio Computer Co Ltd | Electronic musical instrument |
DE2954065C2 (en) * | 1978-03-18 | 1985-09-19 | Casio Computer Co., Ltd., Tokio/Tokyo | Electronic musical instrument |
US4212221A (en) * | 1978-03-30 | 1980-07-15 | Allen Organ Company | Method and apparatus for note attack and decay in an electronic musical instrument |
DE2818083C2 (en) * | 1978-04-25 | 1985-10-31 | National Research Development Corp., London | Digital music tone generator |
GB1601749A (en) * | 1978-05-25 | 1981-11-04 | Kazmin E V | Digital computing device |
US4256002A (en) * | 1978-06-20 | 1981-03-17 | The Wurlitzer Company | Large scale integrated circuit generator chip for electronic organ |
US4253366A (en) * | 1978-06-20 | 1981-03-03 | The Wurlitzer Company | Large scale integrated circuit chip for an electronic organ |
US4203337A (en) * | 1978-06-20 | 1980-05-20 | The Wurlitzer Company | Large scale integrated circuit chip for an electronic organ |
JPS5526560A (en) * | 1978-08-16 | 1980-02-26 | Kawai Musical Instr Mfg Co | Electronic musical instrument |
DE2837114C2 (en) * | 1978-08-25 | 1982-09-02 | Matth. Hohner Ag, 7218 Trossingen | Musical instrument |
GB2032159B (en) * | 1978-09-28 | 1982-11-24 | Rca Gmbh | Electronic tone generator |
US4176573A (en) * | 1978-10-13 | 1979-12-04 | Kawai Musical Instrument Mfg. Co. Ltd. | Intrakeyboard coupling and transposition control for a keyboard musical instrument |
GB2032162B (en) * | 1978-10-18 | 1982-11-17 | Ellen L W | Recording of signals characterising the playing of a musical instrument |
FR2452145A2 (en) * | 1979-03-23 | 1980-10-17 | Deforeit Christian | Polyphonic digitally controlled musical synthesiser - has memory bank forming virtual keyboard between keyboard manuals and synthesising circuits |
US4279186A (en) * | 1978-11-21 | 1981-07-21 | Deforeit Christian J | Polyphonic synthesizer of periodic signals using digital techniques |
FR2442485A1 (en) * | 1978-11-21 | 1980-06-20 | Deforeit Christian | Polyphonic digitally controlled musical synthesiser - has memory bank forming virtual keyboard between keyboard manuals and synthesising circuits |
DE2850652C2 (en) * | 1978-11-22 | 1984-06-28 | Siemens AG, 1000 Berlin und 8000 München | Digital semiconductor circuit |
US4245542A (en) * | 1978-11-27 | 1981-01-20 | Allen Organ Company | Method and apparatus for timbre control in an electronic musical instrument |
US4215619A (en) * | 1978-12-22 | 1980-08-05 | Cbs Inc. | System for recording and automatic playback of a musical performance |
US4244260A (en) * | 1978-12-28 | 1981-01-13 | Norlin Industries, Inc. | Footage volume control circuit |
US4228714A (en) * | 1979-01-02 | 1980-10-21 | Kimball International, Inc. | Multiplex chime generator |
FR2447112A1 (en) * | 1979-01-22 | 1980-08-14 | Thomson Csf | Signal frequency generator for musical instrument - uses single oscillator and memory controlled dividers |
JPS55140892A (en) * | 1979-04-19 | 1980-11-04 | Nippon Musical Instruments Mfg | Musical tone controller for electronic musical instrument |
FR2459524A1 (en) * | 1979-06-15 | 1981-01-09 | Deforeit Christian | POLYPHONIC DIGITAL SYNTHEIZER OF PERIODIC SIGNALS AND MUSICAL INSTRUMENT COMPRISING SUCH A SYNTHESIZER |
JPS5950072B2 (en) * | 1979-09-13 | 1984-12-06 | カシオ計算機株式会社 | Auto power off device |
DE3000704C2 (en) * | 1980-01-10 | 1983-12-01 | Reinhard 5401 Emmelshausen Franz | Transposition arrangement for the tone generator of an electronic musical instrument |
US4320683A (en) * | 1980-01-14 | 1982-03-23 | Allen Organ Company | Asynchronous interface for keying electronic musical instruments using multiplexed note selection |
JPS56117291A (en) * | 1980-02-20 | 1981-09-14 | Matsushita Electric Ind Co Ltd | Electronec musical instrument |
US4380184A (en) * | 1980-04-17 | 1983-04-19 | Matsushita Electrical Industrial Co., Ltd. | Electronic musical instrument |
US4287805A (en) * | 1980-04-28 | 1981-09-08 | Norlin Industries, Inc. | Digital envelope modulator for digital waveform |
US4366739A (en) * | 1980-05-21 | 1983-01-04 | Kimball International, Inc. | Pedalboard encoded note pattern generation system |
DE3023581C2 (en) * | 1980-06-24 | 1983-11-10 | Matth. Hohner Ag, 7218 Trossingen | Method for the digital envelope control of a polyphonic music synthesis instrument and circuit arrangement for carrying out the method |
US4470333A (en) * | 1980-07-03 | 1984-09-11 | The Wurlitzer Company | Generation of musical tones from multiplexed serial data |
JPS5754995A (en) * | 1980-09-20 | 1982-04-01 | Nippon Musical Instruments Mfg | Electronic musical instrument |
US4446770A (en) * | 1980-09-25 | 1984-05-08 | Kimball International, Inc. | Digital tone generation system utilizing fixed duration time functions |
US4351219A (en) * | 1980-09-25 | 1982-09-28 | Kimball International, Inc. | Digital tone generation system utilizing fixed duration time functions |
US4318326A (en) * | 1980-12-29 | 1982-03-09 | Kimball International, Inc. | Plural manual organ having transposer |
US4357851A (en) * | 1981-03-11 | 1982-11-09 | Allen Organ Company | Method and apparatus for producing mixture tones in an electronic musical instrument |
US4375178A (en) * | 1981-03-20 | 1983-03-01 | Allen Organ Company | Dynamic frequency modulation controller for an electronic musical instrument |
US4619174A (en) * | 1981-04-15 | 1986-10-28 | Nippon Gakki Seizo Kabushiki Kaisha | Electronic musical instrument |
US4352312A (en) * | 1981-06-10 | 1982-10-05 | Allen Organ Company | Transient harmonic interpolator for an electronic musical instrument |
US4429604A (en) | 1981-06-22 | 1984-02-07 | Kimball International, Inc. | Fill note generation system for microcomputer controlled organ |
US4403536A (en) * | 1981-06-22 | 1983-09-13 | Kimball International, Inc. | Microcomputer interfaced electronic organ |
FR2517450B1 (en) * | 1981-11-30 | 1988-07-22 | Sedatelec | DEVICE FOR GENERATING MUSIC NOTES |
US4475428A (en) * | 1982-09-28 | 1984-10-09 | Kimball International, Inc. | Pedal capture keyer system |
US4444082A (en) * | 1982-10-04 | 1984-04-24 | Allen Organ Company | Modified transient harmonic interpolator for an electronic musical instrument |
GB2136170A (en) * | 1983-03-03 | 1984-09-12 | Electronic Automation Ltd | Method and apparatus for accessing a memory system |
JPS59195283A (en) * | 1983-04-20 | 1984-11-06 | ヤマハ株式会社 | Electronic musical instrument |
FR2579390A1 (en) * | 1985-03-22 | 1986-09-26 | Enertec | DIGITAL WAVEFORM GENERATOR AND METHOD THEREOF |
JPH06100912B2 (en) * | 1985-07-25 | 1994-12-12 | ヤマハ株式会社 | Electronic musical instrument |
EP0235538B1 (en) * | 1986-01-31 | 1992-04-22 | Casio Computer Company Limited | Waveform generator for electronic musical instrument |
US4722259A (en) * | 1986-03-31 | 1988-02-02 | Kawai Musical Instruments Mfg. Co., Ltd. | Keyswitch actuation detector for an electronic musical instrument |
US4969385A (en) * | 1988-01-19 | 1990-11-13 | Gulbransen, Inc. | Reassignment of digital oscillators according to amplitude |
JP2525853B2 (en) * | 1988-03-17 | 1996-08-21 | ローランド株式会社 | Continuous hit processing device for electronic musical instruments |
US5159141A (en) * | 1990-04-23 | 1992-10-27 | Casio Computer Co., Ltd. | Apparatus for controlling reproduction states of audio signals recorded in recording medium and generation states of musical sound signals |
JP2545008B2 (en) * | 1991-11-21 | 1996-10-16 | ソニー・テクトロニクス株式会社 | Variable frequency signal generation method |
JP2722907B2 (en) * | 1991-12-13 | 1998-03-09 | ヤマハ株式会社 | Waveform generator |
JP3180708B2 (en) * | 1997-03-13 | 2001-06-25 | ヤマハ株式会社 | Sound source setting information communication device |
US8083499B1 (en) | 2003-12-01 | 2011-12-27 | QuaLift Corporation | Regenerative hydraulic lift system |
EP1812929A4 (en) * | 2004-10-01 | 2017-05-10 | Novelorg Inc. | Proportional electromagnet actuator and control system |
ATE373854T1 (en) * | 2005-06-17 | 2007-10-15 | Yamaha Corp | MUSIC SOUND WAVEFORM SYNTHESIZER |
CN101393478B (en) * | 2007-09-21 | 2011-08-24 | 鹏智科技(深圳)有限公司 | Electronic device with sound cue function for induction push-button |
US8735706B2 (en) * | 2010-05-19 | 2014-05-27 | Sydney Mathews | Musical instrument keyboard having identically shaped black and white keys |
FR2982054B1 (en) * | 2011-10-28 | 2014-06-20 | Ingenico Sa | METHOD AND DEVICE FOR MANAGING A KEY MATRIX, COMPUTER PROGRAM PRODUCT, AND CORRESPONDING STORAGE MEDIUM |
US8847051B2 (en) * | 2012-03-28 | 2014-09-30 | Michael S. Hanks | Keyboard guitar including transpose buttons to control tuning |
US10157602B2 (en) | 2016-03-22 | 2018-12-18 | Michael S. Hanks | Musical instruments including keyboard guitars |
EP3260977B1 (en) * | 2016-06-21 | 2019-02-20 | Stichting IMEC Nederland | A circuit and a method for processing data |
WO2018027011A1 (en) * | 2016-08-03 | 2018-02-08 | Mercurial Modulation, LLC | Modulating keyboard with relative transposition mechanism for electronic keyboard musical instruments |
Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3163850A (en) * | 1958-08-29 | 1964-12-29 | Ibm | Record scatter variable |
US3267433A (en) * | 1962-08-24 | 1966-08-16 | Ibm | Computing system with special purpose index registers |
US3328770A (en) * | 1964-06-26 | 1967-06-27 | Ibm | Address register |
US3337852A (en) * | 1964-06-05 | 1967-08-22 | Honeywell Inc | Information handling apparatus |
US3417378A (en) * | 1966-09-13 | 1968-12-17 | Burroughs Corp | Multiple frequency data handling system |
US3515792A (en) * | 1967-08-16 | 1970-06-02 | North American Rockwell | Digital organ |
US3610799A (en) * | 1969-10-30 | 1971-10-05 | North American Rockwell | Multiplexing system for selection of notes and voices in an electronic musical instrument |
US3696201A (en) * | 1970-11-12 | 1972-10-03 | Wurlitzer Co | Digital organ system |
US3697661A (en) * | 1971-10-04 | 1972-10-10 | North American Rockwell | Multiplexed pitch generator system for use in a keyboard musical instrument |
US3700781A (en) * | 1972-01-03 | 1972-10-24 | Kawai Musical Instr Mfg Co | Electronic musical instrument |
Family Cites Families (31)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2401372A (en) * | 1942-12-31 | 1946-06-04 | Bell Telephone Labor Inc | Electronic musical instrument |
US2900861A (en) * | 1947-06-06 | 1959-08-25 | Davis Merlin | Electronic musical instruments |
US2601265A (en) * | 1947-06-06 | 1952-06-24 | Davis Merlin | Electronic musical instrument |
US2855816A (en) * | 1951-12-26 | 1958-10-14 | Rca Corp | Music synthesizer |
US3007362A (en) * | 1954-10-05 | 1961-11-07 | Rca Corp | Combination random-probability system |
US2989885A (en) * | 1955-04-14 | 1961-06-27 | Paul A Pearson | Electronic musical instrument and method |
US2918576A (en) * | 1956-11-13 | 1959-12-22 | Baldwin Piano Co | Percussive circuit and assembly |
US3006228A (en) * | 1957-11-14 | 1961-10-31 | White James Paul | Circuit for use in musical instruments |
NL245097A (en) * | 1958-11-07 | |||
US3255296A (en) * | 1961-03-02 | 1966-06-07 | Richard H Peterson | Player controlled dynamic variation of pitch and/or timbre |
US3184716A (en) * | 1961-04-20 | 1965-05-18 | Bendix Corp | Guarded tone signalling |
GB995739A (en) * | 1961-09-29 | 1965-06-23 | Elektronische Rechenmasch Ind | An arrangement for the operation of information stores |
US3297812A (en) * | 1963-06-21 | 1967-01-10 | Warwick Electronics Inc | Gated function switches in electric organ |
US3316341A (en) * | 1963-11-29 | 1967-04-25 | Columbia Records Distrib Corp | Electrical musical instruments |
US3358068A (en) * | 1964-06-26 | 1967-12-12 | Seeburg Corp | Automatic rhythm device |
US3383452A (en) * | 1964-06-26 | 1968-05-14 | Seeburg Corp | Musical instrument |
JPS5031822B1 (en) * | 1965-04-30 | 1975-10-15 | ||
US3435123A (en) * | 1965-05-24 | 1969-03-25 | Hammond Corp | Electrical musical instrument keying system |
US3417188A (en) * | 1965-06-23 | 1968-12-17 | Baldwin Co D H | Preference circuit for electronic musical instrument utilizing pulse amplitude discrimination and zero-crossing detector |
US3439569A (en) * | 1965-06-24 | 1969-04-22 | Warwick Electronics Inc | Electrical musical instrument |
US3383453A (en) * | 1965-06-28 | 1968-05-14 | Electro Music | Percussion circuit for electronic organs |
GB1173747A (en) * | 1966-01-08 | 1969-12-10 | Eliana D Agata | A Device for Composing and Playing Musical Motifs |
US3478633A (en) * | 1966-02-07 | 1969-11-18 | Seeburg Corp | Counter resetting arrangement for rhythm accompaniment starting |
US3476864A (en) * | 1966-03-09 | 1969-11-04 | Baldwin Co D H | Electronic organ reiteration system utilizing a zero-crossing preference circuit |
US3465088A (en) * | 1966-05-31 | 1969-09-02 | Hammond Corp | Musical instrument percussive keyer with variable signal decay |
US3519723A (en) * | 1966-12-20 | 1970-07-07 | James A Wiest | Sustain tone device for electrical musical instrument |
US3518352A (en) * | 1967-06-30 | 1970-06-30 | Warwick Electronics Inc | Rhythm generating circuit for musical instrument |
USRE26521E (en) * | 1967-08-08 | 1969-02-11 | Automatic repetitive rhythm instrument ttmino circuitry | |
US3516318A (en) * | 1968-01-02 | 1970-06-23 | Baldwin Co D H | Frequency changer employing opto-electronics |
US3446904A (en) * | 1968-01-04 | 1969-05-27 | Warwick Electronics Inc | Key system for electrical musical instrument |
US3544693A (en) * | 1968-11-29 | 1970-12-01 | Robert W Tripp | Electronic control system for musical instrument |
-
1969
- 1969-10-30 US US872597A patent/US3610799A/en not_active Expired - Lifetime
- 1969-10-30 US US872598A patent/US3610805A/en not_active Expired - Lifetime
- 1969-10-30 US US872600A patent/US3610806A/en not_active Expired - Lifetime
- 1969-10-30 US US872599A patent/US3610800A/en not_active Expired - Lifetime
- 1969-11-10 US US875178A patent/US3639913A/en not_active Expired - Lifetime
-
1971
- 1971-08-11 US US00170992A patent/US3743755A/en not_active Expired - Lifetime
- 1971-08-25 GB GB3994671A patent/GB1317385A/en not_active Expired
- 1971-08-26 AU AU32776/71A patent/AU449757B2/en not_active Expired
- 1971-09-07 NL NLAANVRAGE7112290,A patent/NL174997C/en not_active IP Right Cessation
- 1971-09-16 BE BE772689A patent/BE772689A/en not_active IP Right Cessation
- 1971-09-20 FR FR7133790A patent/FR2153149B1/fr not_active Expired
- 1971-09-28 DE DE2149104A patent/DE2149104C3/en not_active Expired
- 1971-10-15 CH CH1505971A patent/CH559956A5/xx not_active IP Right Cessation
Patent Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3163850A (en) * | 1958-08-29 | 1964-12-29 | Ibm | Record scatter variable |
US3267433A (en) * | 1962-08-24 | 1966-08-16 | Ibm | Computing system with special purpose index registers |
US3337852A (en) * | 1964-06-05 | 1967-08-22 | Honeywell Inc | Information handling apparatus |
US3328770A (en) * | 1964-06-26 | 1967-06-27 | Ibm | Address register |
US3417378A (en) * | 1966-09-13 | 1968-12-17 | Burroughs Corp | Multiple frequency data handling system |
US3515792A (en) * | 1967-08-16 | 1970-06-02 | North American Rockwell | Digital organ |
US3515792B1 (en) * | 1967-08-16 | 1987-08-18 | ||
US3610799A (en) * | 1969-10-30 | 1971-10-05 | North American Rockwell | Multiplexing system for selection of notes and voices in an electronic musical instrument |
US3696201A (en) * | 1970-11-12 | 1972-10-03 | Wurlitzer Co | Digital organ system |
US3697661A (en) * | 1971-10-04 | 1972-10-10 | North American Rockwell | Multiplexed pitch generator system for use in a keyboard musical instrument |
US3700781A (en) * | 1972-01-03 | 1972-10-24 | Kawai Musical Instr Mfg Co | Electronic musical instrument |
Cited By (52)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3854365A (en) * | 1971-07-31 | 1974-12-17 | Nippon Musical Instruments Mfg | Electronic musical instruments reading memorized waveforms for tone generation and tone control |
US3916750A (en) * | 1972-02-04 | 1975-11-04 | Baldwin Co D H | Electronic organ employing time position multiplexed signals |
US3809786A (en) * | 1972-02-14 | 1974-05-07 | Deutsch Res Lab | Computor organ |
US3809788A (en) * | 1972-10-17 | 1974-05-07 | Nippon Musical Instruments Mfg | Computor organ using parallel processing |
US3809789A (en) * | 1972-12-13 | 1974-05-07 | Nippon Musical Instruments Mfg | Computor organ using harmonic limiting |
US3882751A (en) * | 1972-12-14 | 1975-05-13 | Nippon Musical Instruments Mfg | Electronic musical instrument employing waveshape memories |
US3809792A (en) * | 1973-01-05 | 1974-05-07 | Nippon Musical Instruments Mfg | Production of celeste in a computor organ |
US3809790A (en) * | 1973-01-31 | 1974-05-07 | Nippon Musical Instruments Mfg | Implementation of combined footage stops in a computor organ |
US3903775A (en) * | 1973-03-08 | 1975-09-09 | Nippon Musical Instruments Mfg | Electronic musical instrument |
US3842184A (en) * | 1973-05-07 | 1974-10-15 | Chicago Musical Instr Co | Musical instrument having automatic arpeggio system |
US3878750A (en) * | 1973-11-21 | 1975-04-22 | Charles A Kapps | Programmable music synthesizer |
US3894463A (en) * | 1973-11-26 | 1975-07-15 | Canadian Patents Dev | Digital tone generator |
US3915047A (en) * | 1974-01-02 | 1975-10-28 | Ibm | Apparatus for attaching a musical instrument to a computer |
US3978755A (en) * | 1974-04-23 | 1976-09-07 | Allen Organ Company | Frequency separator for digital musical instrument chorus effect |
US3929053A (en) * | 1974-04-29 | 1975-12-30 | Nippon Musical Instruments Mfg | Production of glide and portamento in an electronic musical instrument |
US3913442A (en) * | 1974-05-16 | 1975-10-21 | Nippon Musical Instruments Mfg | Voicing for a computor organ |
DE2524062A1 (en) * | 1974-05-31 | 1975-12-11 | Nippon Musical Instruments Mfg | ELECTRONIC MUSICAL INSTRUMENT WITH VIBRATO GENERATION |
DE2523881A1 (en) * | 1974-05-31 | 1975-12-11 | Nippon Musical Instruments Mfg | ELECTRONIC MUSICAL INSTRUMENT WITH NOISE SUPPLY EFFECT |
US4026180A (en) * | 1974-05-31 | 1977-05-31 | Nippon Gakki Seizo Kabushiki Kaisha | Electronic musical instrument |
US3982461A (en) * | 1974-06-06 | 1976-09-28 | Kabushiki Kaisha Kawai Gakki Seisakusho | Musical-tone signal forming apparatus for electronic musical instrument |
US4030395A (en) * | 1974-06-06 | 1977-06-21 | Kabushiki Kaisha Kawai Gakki Seisakusho | Musical-tone signal forming apparatus for an electronic musical instrument |
JPS5116015A (en) * | 1974-07-31 | 1976-02-09 | Matsushita Electric Ind Co Ltd | |
US4041825A (en) * | 1974-10-15 | 1977-08-16 | Pascetta Armand N | Keyboard assignment system for a polyphonic electronic musical instrument |
US3951028A (en) * | 1974-10-23 | 1976-04-20 | Kimball International, Inc. | Electronic organ and method of operation |
US3952623A (en) * | 1974-11-12 | 1976-04-27 | Nippon Gakki Seizo Kabushiki Kaisha | Digital timing system for an electronic musical instrument |
US3955460A (en) * | 1975-03-26 | 1976-05-11 | C. G. Conn Ltd. | Electronic musical instrument employing digital multiplexed signals |
US4046047A (en) * | 1975-08-11 | 1977-09-06 | Warwick Electronics Inc. | Note selector circuit for electronic musical instrument |
US4148241A (en) * | 1975-08-26 | 1979-04-10 | Norlin Music, Inc. | Electronic musical instrument with means for automatically generating chords and harmony |
DE2711511A1 (en) * | 1976-03-16 | 1977-09-22 | Christian Deforeit | POLYPHONIC ELECTRONIC MUSICAL INSTRUMENT |
US4202234A (en) * | 1976-04-28 | 1980-05-13 | National Research Development Corporation | Digital generator for musical notes |
US4463647A (en) * | 1976-08-16 | 1984-08-07 | Melville Clark, Jr. | Musical instrument |
US4177706A (en) * | 1976-09-08 | 1979-12-11 | Greenberger Alan J | Digital real time music synthesizer |
US4114496A (en) * | 1977-01-10 | 1978-09-19 | Kawai Musical Instrument Mfg. Co., Ltd. | Note frequency generator for a polyphonic tone synthesizer |
US4495846A (en) * | 1977-11-14 | 1985-01-29 | Williams S Keith | Electronic musical instrument |
US4218948A (en) * | 1977-12-27 | 1980-08-26 | Nippon Gakki Seizo Kabushiki Kaisha | Electronic musical instrument of key code processing type |
US4192007A (en) * | 1978-05-30 | 1980-03-04 | Lorain Products Corporation | Programmable ringing generator |
US4338844A (en) * | 1979-02-17 | 1982-07-13 | Kabushiki Kaisha Kawai Gakki Seisakusho | Tone source circuit for electronic musical instruments |
US4338674A (en) * | 1979-04-05 | 1982-07-06 | Sony Corporation | Digital waveform generating apparatus |
US4256003A (en) * | 1979-07-19 | 1981-03-17 | Kawai Musical Instrument Mfg. Co., Ltd. | Note frequency generator for an electronic musical instrument |
WO1981000779A1 (en) * | 1979-09-14 | 1981-03-19 | Norlin Ind Inc | Automatic rhythm generator |
US4242936A (en) * | 1979-09-14 | 1981-01-06 | Norlin Industries, Inc. | Automatic rhythm generator |
DE3023580A1 (en) * | 1980-06-24 | 1982-01-07 | Matth. Hohner Ag, 7218 Trossingen | METHOD FOR PHASE SYNCHRONIZING DIGITALLY SYNTHETIZED TOOLS OF A MUSICAL INSTRUMENT, AND CIRCUIT ARRANGEMENT FOR IMPLEMENTING THE METHOD |
USRE33558E (en) * | 1980-12-01 | 1991-03-26 | Yamaha Corporation | Electronic musical instrument forming tone waveforms |
US4409876A (en) * | 1980-12-01 | 1983-10-18 | Nippon Gakki Seizo Kabushiki Kaisha | Electronic musical instrument forming tone waveforms |
US4513365A (en) * | 1982-02-11 | 1985-04-23 | Reinhard Franz | Function selector |
US4561337A (en) * | 1983-06-08 | 1985-12-31 | Nippon Gakki Seizo Kabushiki Kaisha | Digital electronic musical instrument of pitch synchronous sampling type |
US4936179A (en) * | 1986-10-04 | 1990-06-26 | Kabushiki Kaisha Kawai Gakki Seisakusho | Electronic musical instrument |
JPH0239099A (en) * | 1988-07-28 | 1990-02-08 | Ricoh Co Ltd | Musical sound generator |
US5457455A (en) * | 1992-09-22 | 1995-10-10 | Rockwell International Corporation | Real time keyboard scanner |
US6326537B1 (en) * | 1995-09-29 | 2001-12-04 | Yamaha Corporation | Method and apparatus for generating musical tone waveforms by user input of sample waveform frequency |
US6509519B2 (en) | 1995-09-29 | 2003-01-21 | Yamaha Corporation | Method and apparatus for generating musical tone waveforms by user input of sample waveform frequency |
US6410838B1 (en) * | 1999-12-16 | 2002-06-25 | Yamaha Corporation | Musical sound signal synthesizer and method for synthesizing musical sound signals using nonlinear transformer |
Also Published As
Publication number | Publication date |
---|---|
NL7112290A (en) | 1973-03-09 |
GB1317385A (en) | 1973-05-16 |
AU449757B2 (en) | 1974-06-20 |
FR2153149A1 (en) | 1973-05-04 |
NL174997C (en) | 1984-04-02 |
US3610806A (en) | 1971-10-05 |
DE2149104C3 (en) | 1981-06-11 |
CH559956A5 (en) | 1975-03-14 |
US3610799A (en) | 1971-10-05 |
AU3277671A (en) | 1973-03-01 |
FR2153149B1 (en) | 1975-08-29 |
NL174997B (en) | 1984-04-02 |
DE2149104B2 (en) | 1980-10-09 |
DE2149104A1 (en) | 1973-04-12 |
US3610800A (en) | 1971-10-05 |
US3610805A (en) | 1971-10-05 |
US3639913A (en) | 1972-02-01 |
BE772689A (en) | 1972-01-17 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US3743755A (en) | Method and apparatus for addressing a memory at selectively controlled rates | |
US3899951A (en) | Key switch scanning and encoding system | |
US4022098A (en) | Keyboard switch detect and assignor | |
US3755608A (en) | Apparatus and method for selectively alterable voicing in an electrical instrument | |
US3844379A (en) | Electronic musical instrument with key coding in a key address memory | |
GB1440488A (en) | Electronic musical instrument | |
US4184403A (en) | Method and apparatus for introducing dynamic transient voices in an electronic musical instrument | |
US4119005A (en) | System for generating tone source waveshapes | |
US4114497A (en) | Electronic musical instrument having a coupler effect | |
US4026180A (en) | Electronic musical instrument | |
US3979989A (en) | Electronic musical instrument | |
US4176573A (en) | Intrakeyboard coupling and transposition control for a keyboard musical instrument | |
US4122743A (en) | Electronic musical instrument with glide | |
US4194425A (en) | Key code generator | |
EP0258798B1 (en) | Apparatus for generating tones by use of a waveform memory | |
US4166405A (en) | Electronic musical instrument | |
US4194426A (en) | Echo effect circuit for an electronic musical instrument | |
GB1484804A (en) | Key switch system | |
US3872765A (en) | Chord selection apparatus for an electronic musical instrument | |
US4238984A (en) | Electronic musical instrument | |
US4562763A (en) | Waveform information generating system | |
US3974478A (en) | Key switch scanning and encoding system | |
US5340940A (en) | Musical tone generation apparatus capable of writing/reading parameters at high speed | |
US4178825A (en) | Musical tone synthesizer for generating a marimba effect | |
US5208415A (en) | Fluctuation generator for use in electronic musical instrument |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent suit(s) filed | ||
AS | Assignment |
Owner name: MUSICCO, LLC, PENNSYLVANIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:ALLEN ORGAN COMPANY;REEL/FRAME:018194/0822 Effective date: 20060901 |