Computerized music apparatus processing waveform to create sound effect, a method of operating such an apparatus, and a machine-readable media

A computerized music apparatus is installed with a program which is executed to perform reproduction of a musical tone by reading out a corresponding waveform. A storage is provided for storing a plurality of waveforms corresponding to different musical tones, each waveform being stored in the form of a sequence of amplitude value data arranged at a given sampling period. Tapping pads are provided for designating at least one of the stored waveforms to command reproduction of a corresponding one of the musical tones. A panel switch is operable by a user for switching the reproduction of the musical tone between a normal mode and an optional mode. A CPU is allotted with relatively high performance under the normal mode for concurrently reading out a number of the designated waveforms from the storage according to the program so as to concurrently reproduce the number of the corresponding musical tones. Otherwise, the CPU is allotted with relatively low performance under the optional mode such that the number of the musical tones concurrently reproduced under the optional mode is reduced as compared to that under the normal mode while the CPU is allotted with additional performance under the optional mode for digitally processing the designated waveform to impart a scratch effect to the reproduced musical tone according to the program. The scratch effect may be also applied to a fresh waveform inputted from an external source in real time.

BACKGROUND OF THE INVENTION 
The present invention relates to a musical tone generating apparatus for 
reading out waveform data stored in a digital memory to generate a musical 
tone using the software. The present invention also relates to a musical 
tone generating apparatus for processing waveform data inputted in real 
time using the software. In particular, the invention relates to a musical 
tone generating apparatus capable of applying a filter process, a pitch 
process or a scratch process to the generated musical tones while a number 
of the musical tones is reduced as compared to normal generation or 
reproduction of the musical tones. Further, the present invention relates 
to a musical tone generating apparatus capable of achieving a scratch 
effect in a pseudo fashion. 
A software sound source has been known, wherein waveform data sampled from 
original musical tones is stored in a storage device in advance. The 
stored waveform data is read out by a software or program in response to 
operation of a manual implement. However, the conventional software sound 
source is functionally fixed and therefore has rather limited applications 
and poor performance. In recent years, a high performance sound source has 
been demanded, which can impart various effects such as a digital tone 
color filter process and a scratch effect to a musical tone. Scratch is 
originally a technique for producing a special effect tone by forcibly 
moving an analog record disk by hand while the record disk is driven on a 
turntable, so as to change a replaying speed irregularly. Conventionally, 
an analog record disk is used to impart the scratch effect. There has been 
no digital musical tone generating apparatus which realizes such a scratch 
effect. 
SUMMARY OF THE INVENTION 
In a musical tone generating apparatus which reads out waveform data stored 
in a digital memory to generate musical tones using software, an object of 
the present invention is to achieve extended performance which could not 
be realized by the conventional software sound source so as to apply 
various processes and effects to the musical tones while the number of the 
generated musical tones may be saved. Further, in a musical tone 
generating apparatus which directly outputs waveform data inputted in real 
time, an object of the present invention is to achieve high performance 
which could not be realized by the conventional software sound source so 
as to apply various processes and effects to the externally inputted 
waveform data. Moreover, it is an object of the present invention to 
realize a scratch effect in a pseudo fashion in a musical tone generating 
apparatus which reads out waveform data stored in a digital memory or 
which directly outputs waveform data inputted in real time. 
According to a first aspect of the invention, a computerized music 
apparatus is installed with a program which is executed to perform 
reproduction of a musical tone by reading out a corresponding waveform. 
The computerized music apparatus comprises storage means for storing a 
plurality of waveforms corresponding to different musical tones, each 
waveform being stored in the form of a sequence of amplitude value data 
arranged at a given sampling period, designating means for designating at 
least one of the stored waveforms to command reproduction of a 
corresponding one of the musical tones, switching means operable by a user 
for switching the reproduction of the musical tone between a normal mode 
and an optional mode, and reproducing means allotted with relatively high 
performance under the normal mode for concurrently reading out a number of 
the designated waveforms from the storage means according to the program 
so as to concurrently reproduce the number of the corresponding musical 
tones, otherwise the reproducing means being allotted with relatively low 
performance under the optional mode such that the number of the musical 
tones concurrently reproduced under the optional mode is reduced as 
compared to that under the normal mode while the reproducing means is 
allotted with additional performance under the optional mode for digitally 
processing the designated waveform to impart a specific sound effect to 
the reproduced musical tone according to the program. 
In a specific form, the switching means comprises means switchable between 
the normal mode and a filter optional mode such that the reproducing means 
operates under the filter optional mode for digitally processing the 
designated waveform by filtering to impart the specific sound effect such 
as to modify a timbre of the reproduced musical tone. In another specific 
form, the switching means comprises means switchable between the normal 
mode and a pitch optional mode such that the reproducing means operates 
under the pitch optional mode for digitally processing the designated 
waveform by changing reading speed of the designated waveform to impart 
the specific sound effect such as to modify a pitch of the reproduced 
musical tone. In such a case, the computerized music apparatus further 
includes pitch specifying means operable by the user for specifying a 
pitch of a musical tone to be reproduced so that the reproducing means 
operates under the pitch optional mode to impart the pitch specified by 
the pitch specifying means to the reproduced musical tone. Moreover, the 
designating means and the pitch specifying means comprise a common 
implement manually operable by the user such that the common implement is 
used as the designating means for designating the waveform under the 
normal mode while the common implement is used as both of the designating 
means for designating the waveform and the pitch specifying means for 
specifying the pitch of the musical tone corresponding to the designated 
waveform. 
In a further specific form, the switching means comprises means switchable 
between the normal mode and a scratch optional mode such that the 
reproducing means operates under the scratch optional mode for digitally 
processing the designated waveform by irregularly changing reading 
addresses of the designated waveform to impart the specific sound effect 
such as to scratch the corresponding musical tone. In such a case, the 
computerized music apparatus further comprises a scratch implement 
manipulated by the user to input scratch operation so that the reproducing 
means operates under the scratch optional mode for changing the reading 
addresses of the designated waveform according to the inputted scratch 
operation. 
In a second aspect of the invention, a computerized music apparatus is 
installed with a program which is executed to perform reproduction of a 
musical tone by reading out a corresponding waveform. The computerized 
music apparatus comprises storage means for provisionally storing a 
plurality of waveforms corresponding to different musical tones, each 
waveform being stored in the form of a sequence of amplitude value data 
arranged at a given sampling period, designating means for designating at 
least one of the stored waveforms to command reproduction of a 
corresponding one of the musical tones, receiving means for receiving a 
fresh waveform in real time basis when the fresh waveform is inputted from 
an external source, switching means operable by a user for switching the 
reproduction of the musical tone between a normal mode and an optional 
mode, and reproducing means operative under the normal mode for reading 
out the stored waveform designated by the designating means from the 
storage means according to the program so as to reproduce the musical tone 
corresponding to the designated waveform, otherwise the reproducing means 
being operative under the optional mode for suspending or stopping the 
reading of the stored waveform designated by the designating means and 
instead for processing the fresh waveform received by the receiving means 
so as to reproduce the musical tone corresponding to the fresh waveform 
such that a specific sound effect is imparted to the reproduced musical 
tone according to the program. In a specific form, the reproducing means 
includes filtering means operative under the optional mode for processing 
the fresh waveform by digital filtering to thereby impart the specific 
sound effect such as to modify a timbre of the reproduced musical tone. In 
another specific form, the reproducing means includes scratching means 
operative under the optional mode for irregularly processing the fresh 
waveform to thereby impart the specific sound effect such as to scratch 
the reproduced musical tone. In such a case, the computerized music 
apparatus further comprises a scratch implement manipulated by the user to 
input scratch operation so that the scratching means operates according to 
the inputted scratch operation for irregularly changing reading addresses 
of the fresh waveform which is temporarily stored after the same is 
received by the receiving means to thereby scratch the reproduced musical 
tone. 
In a third aspect of the invention, a music apparatus reproduces a musical 
tone by reading out a corresponding waveform according to a variable 
reading address so as to introduce a scratch effect into the reproduced 
musical tone in response to touch action. The musical apparatus comprises 
storage means for storing a waveform in the form of a sequence of 
amplitude value data arranged at a given sampling period to represent a 
corresponding musical tone, a detecting implement having a length to 
receive the touch action for detecting a point of the touch action along 
the length and for outputting a positional value corresponding to the 
detected point of the touch action, retrieving means for periodically 
retrieving the positional value outputted from the detecting implement to 
monitor the touch action, and reproducing means for variably determining 
each reading address according to the retrieved ones of the positional 
values and for successively reading out the waveform from the storage 
means according to each determined reading address so as to reproduce the 
corresponding musical tone with the scratch effect. Characterizingly, the 
reproducing means comprises means operative when the touch action is 
initiated for starting to read out the waveform from a predetermined start 
reading address, and being operative during the course of the touch action 
for continuing to successively read out the waveform according to each 
determined reading address. Further, the retrieving means comprises means 
for differentially processing the periodically retrieved positional values 
to compute a velocity of the touch action, and the reproducing means 
comprises means for determining a variable number according to the 
velocity of the touch action and for accumulating the variable number to a 
preceding reading address to determine a succeeding reading address. 
Moreover, the storage means comprises means for storing a waveform which 
is inputted from an external source in real time basis, and the 
reproducing means comprises means operative when the touch action is not 
commenced for outputting the inputted waveform as it is to reproduce the 
corresponding musical tone without the scratch effect, and being operative 
when the touch action is commenced for stopping the storing and outputting 
of the waveform and instead for successively reading out the waveform from 
the storage means according to the variable reading addresses to reproduce 
the corresponding musical tone with the scratch effect. Preferably, the 
storage means has a memory capacity sufficient to store a complete data 
volume of a fresh waveform newly inputted from the external source on a 
real time basis.

DETAILED DESCRIPTION OF THE INVENTION 
Hereinbelow, embodiments of the present invention will be described with 
reference to the drawings. FIG. 1 is a structural block diagram of a 
sampler which is an embodiment of a musical tone generating apparatus 
according to the present invention. The sampler includes a central 
processing unit (CPU) 101, a read only memory (ROM) 102, a flash memory 
103, a random access memory (RAM) 104, a timer 105, a ribbon controller 
106, a set of operating pads 107, a display 108, a panel switch 109, a 
sampling clock (Fs) generator 110, a sound I/O 112, a DMA (direct memory 
access) controller 113, and a bus line 115. 
The CPU 101 controls operation of the whole system of the sampler. The ROM 
102 stores control programs executed by the CPU 101. The RAM 104 is 
provided with working areas such as various registers and buffers. The 
flash memory 103 is a memory for storing waveform data sampled and 
recorded by this sampler. The recorded waveform data is temporarily stored 
in a recording buffer on the RAM 104. When the recording buffer is filled 
up, the waveform data in the recording buffer is transferred to the flash 
memory 103. Even if the sampler is powered off, the waveform data in the 
flash memory 103 is held. Thus, the sampler has storage means for storing 
a plurality of waveforms corresponding to different musical tones. Each 
waveform is stored in the form of a sequence of amplitude value data 
arranged at a given sampling period to represent the corresponding musical 
tone. 
The timer 105 generates a timer clock signal for causing a timer 
interruption at a given time interval to the CPU 101. By means of the 
timer interruption, the CPU 101 executes various processes such as 
retrieving a detection value of the ribbon controller 106 at a given time 
interval. 
The ribbon controller 106 is an operating implement manipulated by a user 
to perform scratch operation. The ribbon controller 106 is a coordinate 
detecting device which has a linear member of a finite length and which 
outputs a coordinate of a position where a finger or a rod touches the 
linear member. The ribbon controller 106 features that its operation can 
be commenced at an arbitrary position. The ribbon controller 106 outputs a 
default value while no touch action with the finger or the rod occurs, and 
otherwise outputs a coordinate position value when the touch action 
occurs. Thus, it can be determined from the detection value whether the 
ribbon controller 106 is operated or not, that is, whether the touch 
action with the finger or the rod occurs or not. Namely, the detecting 
implement has a length to receive the touch action for detecting a point 
of the touch action along the length and for outputting a positional value 
corresponding to the detected point of the touch action. 
The pads 107 constitute another operating implement manipulated by the user 
to control the tone generation. Specifically, a set of the ten pads 107 
are provided. The recording or sampling of an original musical tone can be 
achieved by designating one of the ten pads 107. In reproduction of the 
recorded tones, a particular one of the pads 107 is tapped by the user so 
that the waveform data recorded corresponding to that pad is read out and 
replayed. Instead of tapping or setting on the pad, it may be arranged to 
perform the tone reproduction by receiving note-on data of a MIDI (musical 
instrument digital interface) signal. The pads 107 constitute designating 
means for designating at least one of the stored waveforms to command 
reproduction of a corresponding one of the musical tones. 
The display 108 is provided for displaying various setting information. The 
panel switch (SW) 109 is a switch group provided on a panel of the sampler 
for the user to perform various setting operations. The panel switch 109 
includes various switches such as a mode change-over switch which 
constitutes switching means for switching the tone reproduction between a 
normal mode and one of various optional modes. 
The Fs clock generator 110 generates a sampling clock of a frequency Fs fed 
to the sound I/O 112. The sound I/O 112 is constituted by an LSI called 
CODEC. The sound I/O 112 has an analog-to-digital (A/D) conversion 
function and a digital-to-analog (D/A) conversion function. The sound I/O 
112 has an A/D input terminal at which an analog musical tone signal 
inputted from an external source 111 is received, and a D/A output 
terminal to which a sound system 114 is connected. The sound I/O 112 has a 
function of compressing waveform data which is obtained by converting the 
received analog musical tone signal from the external source 111 into 
digital data through the A/D conversion function. The waveform data is 
compressed according to the ADPCM (adaptive differential pulse code 
modulation). Further, the sound I/O 112 has another function of performing 
ADPCM expansion to the waveform data which is D/A converted and outputted 
to the sound system 114 through the D/A output terminal. In the embodiment 
of the invention explained here, only the ADPCM compression is actually 
performed at the sound I/O 112, and the ADPCM expansion is performed by 
execution of a given software by the CPU 101. 
The sound I/O 112 is provided therein with two FIFO (first in first out) 
stack regions. One of them is an input FIFO for holding digital waveform 
data inputted via the A/D input terminal, and the other is an output FIFO 
for holding digital waveform data outputted via the D/A output terminal. 
The sound I/O 112 constitutes receiving means for receiving a fresh 
waveform in real time basis when the same is inputted from the external 
source 111. 
Hereinbelow, input/output operations of the sound I/O 112 using the input 
FIFO and the output FIFO will be briefly explained. An analog musical tone 
signal inputted to the A/D input terminal of the sound I/O 112 from the 
external source 111 is A/D converted in response to the sampling clock of 
the frequency Fs, and is then written into the input FIFO (ADPCM 
compressed if necessary). When the waveform data exists in the input FIFO, 
the sound I/O 112 outputs a demand for processing the input waveform data 
to the DMA controller 113. In response to the process demand, the DMA 
controller 113 transfers the data of the input FIFO to a recording buffer 
region prepared in the RAM 104. This data transfer by the DMA controller 
113 is performed such that the DMA controller 113 executes an interruption 
operation relative to the CPU 101 every sampling clock Fs so as to hold 
the bus line 115. The CPU 101 is unconscious of the holding of the bus 
line 115 by the DMA controller 113. The foregoing transfer process of the 
waveform data by the DMA controller 113 during the recording of the 
musical tone will be described later in detail with reference to FIG. 15. 
On the other hand, when the waveform data exists in the output FIFO of the 
sound I/O 112, the waveform data in the output FIFO is D/A converted every 
sampling clock Fs, and is sent to the sound system 114 via the D/A output 
terminal so that the musical tone is emitted. When the waveform data of 
the output FIFO is outputted, there is a room in the output FIFO so that 
the sound I/O 112 outputs a demand for obtaining another waveform data to 
the DMA controller 113. The CPU 101 generates in advance waveform data to 
be outputted, then stores the generated waveform data in a reproduction 
buffer on the RAM 104, and outputs in advance a demand for reproducing the 
waveform data to the DMA controller 113. The DMA controller 113 executes 
an interruption operation every sampling clock Fs relative to the CPU 101 
so as to hold the bus line 115 and transfers the waveform data stored in 
the reproduction buffer of the RAM 104 to the sound I/O 112. The CPU 101 
is unconscious of the transfer of the waveform data by the DMA controller 
113. The waveform data written in the output FIFO is, as described above, 
sent to the sound system 114 every sampling clock Fs so that the musical 
tone is emitted. The foregoing transfer process of the waveform data by 
the DMA controller 113 during the tone reproduction will be described 
later in detail with reference to FIG. 16. 
Further, the sound I/O 112 has a function to directly transfer the waveform 
data inputted at the A/D input terminal to the D/A output terminal so that 
the musical tone signal from the external source 111 is directly outputted 
to the sound system 114 as it is. Connection between the A/D input and the 
D/A output is performed based on an instruction from the CPU 101. Further, 
the CPU 101 is capable of cutting the direct connection between the A/D 
input and the D/A output. 
Next, basic operation of the sampler of FIG. 1 will be briefly explained. 
The sampler has seven operation modes, that is, a normal mode, a sampling 
mode and five optional modes including a filter mode, a pitch mode, a 
scratch mode, an external input (EX) filter mode, and an external input 
(EX) scratch mode. These modes can be switched by means of the mode 
change-over switch provided in the panel switch 109. Hereinbelow, each 
mode will be explained. 
The normal mode is selected for replaying the recorded musical tone. In an 
initial state, the sampler is set the normal mode. In the normal mode, 
when the user taps one of the ten pads 107, the waveform data recorded 
corresponding to that pad is read out from the storage by reproducing 
means composed of the CPU 101 according to an installed program. In the 
normal mode, up to four tones can be reproduced concurrently. 
Specifically, four waveform data recorded corresponding to the tapped four 
pads are replayed simultaneously. When the fifth pad is tapped, the 
reproduced tone corresponding to the pad first tapped is stopped and the 
waveform data corresponding to the newly tapped fifth pad is replayed. 
The sampling mode is selected for recording a fresh waveform. When the 
sampling mode is designated using the mode change-over switch, the user 
simultaneously designates a pad for recording. By this, the musical tone 
inputted from the external source 111 can be recorded corresponding to 
that designated pad. 
In the filter optional mode, only two tones can be reproduced concurrently 
according to pad-on in contrast to the normal mode. Namely, the 
reproducing means is allotted with high performance under the normal mode 
for concurrently reading out at most four number of waveforms, and is 
allotted with low performance in the optional mode such as the filter mode 
for concurrently reading out at most two number of waveforms. Further, 
digital filter processing, specifically, low-pass filter processing is 
applied to those reproduced tones. By operating the ribbon controller 106, 
the user can change a cut-off frequency in the low-pass filter processing. 
Namely, the reproducing means is allotted with additional performance 
under the filter mode for digitally processing the waveform by filtering 
to impart a specific sound effect to the musical tone such as to modify 
timbre of the reproduced tone. 
The pitch mode is selected for reproducing the recorded musical tone with a 
desired pitch shift. In the other operation modes than the pitch mode, the 
musical tone is reproduced at an original pitch as it is. When the pitch 
mode is designated using the mode change-over switch, by simultaneously 
operating one of the pads, the user specifies desired waveform data to be 
replayed in the pitch mode. Thereafter, when the specified one of the ten 
pads is set on, the designated waveform data is replayed with a specified 
pitch corresponding to that pad. Only two tones can be reproduced 
concurrently in this mode. Although the pad for designating the waveform 
to be replayed is used commonly as the pitch specifying means, the pitch 
specifying means may be provided separately from the pad. The waveform is 
digitally processed under the pitch mode by changing reading speed of the 
data such as to shift or modify the original pitch of the corresponding 
musical tone. 
The scratch mode is selected for realizing the scratch operation by the 
user. When the scratch mode is designated using the mode change-over 
switch, the user simultaneously designates desired one of the pads. 
Waveform data corresponding to that pad is subjected to the scratch 
operation. Thereafter, by touching the ribbon controller 106, the waveform 
data starts to be replayed. Further, by moving the touch position on the 
ribbon controller 106, the tone is scratch-replayed. Further, in this 
mode, apart from the scratch reproduction, only two tones can be 
reproduced concurrently in the normal mode using the ten pads. The 
waveform is digitally processed under the scratch mode by irregularly 
changing reading addresses of the data so as to reproduce a musical tone 
with the scratch effect. 
The EX filter mode is selected for filtering fresh waveform data fed from 
the external source 111 and for outputting the filtered waveform data to 
the sound system 114. A cut-off frequency of the filtering can be changed 
by the user by means of the ribbon controller 106. In the EX filter mode, 
it is arranged that the replay of the stored waveform is suspended even if 
the pads are operated by the user. 
The EX scratch mode is selected for applying the scratch operation to the 
fresh waveform fed from the external source 111. In the EX scratch mode, 
when the ribbon controller 106 is not touched, the waveform from the 
external source 111 is outputted as it is to the sound system 114. At a 
moment of touching the ribbon controller 106, the direct sound output to 
the sound system from the external source is stopped, and the scratch 
reproduction by the ribbon controller 106 is performed for the external 
input waveform received at that moment. In the EX scratch mode, it is 
arranged that the replay of the stored waveform corresponding to each pad 
is suspended even upon pad-on. 
Next, registers, buffers and the like provided in the RAM 104 will be 
explained. FIG. 2(a) shows a sound source register provided in the RAM 
104. The sound source register is comprised of 4-channel regions (1ch-4ch) 
for the pad performance and a sound source register sch for the scratch 
reproduction. The register for each channel stores various data such as 
addresses for reading out waveform data and note-on data. 
FIG. 2(b) shows a recording buffer provided in the RAM 104. The recording 
buffer is provided with two buffers, that is, RB0 and RB1, each of which 
can store waveform data of 128 samples. Upon recording, waveform samples 
are stored in one of the recording buffers. Namely, the waveform data fed 
from the external source 111 is transferred to the one recording buffer 
via the input FIFO of the sound I/O 112 by the DMA controller 113. When 
the one recording buffer is filled up, the waveform samples of the one 
recording buffer is written into the flash memory 103 by the CPU 101. 
Along with this, the storage of waveform samples continues into the other 
of the recording buffers. In this fashion, the two recording buffers are 
alternately used for continuously recording the waveform. RBk (k=0 or 1) 
represents the recording buffer currently performing the recording or 
storing of waveform data, while RBk represents the other recording buffer. 
k represents an inversion of k (when k=0, k=1, when k=1, k=0). 
FIG. 2(c) shows a reproducing buffer in the RAM 104. The reproducing buffer 
is provided with two buffers, that is, PB0 and PB1, each of which can 
store waveform data of 128 samples. One of the reproducing buffers is used 
for the tone reproduction. Namely, the waveform data in the one 
reproducing buffer is transferred to the sound I/O 112 by the DMA 
controller 113 and is outputted via the output FIFO. The other reproducing 
buffer is provided to store waveform data to be outputted next by the CPU 
101. In this fashion, the two reproducing buffers are alternately used for 
the tone reproduction. PBr (r=0 or 1) represents the reproducing buffer 
currently transferring waveform data to the sound I/O 112 for 
reproduction, while PBr represents the other reproducing buffer. r 
represents an inversion of r (when r=0, r=1, when r=1, r=0). 
FIG. 2(d) shows a scratch region SR provided in the RAM 104. The scratch 
region SR is prepared when the scratch mode is designated. When the 
scratch mode is set, the waveform data corresponding to the designated pad 
is ADPCM expanded with linear 16 bits, and is developed in an area of the 
RAM 104. It is determined in advance as to which part of the waveform data 
is set to the scratch region SR. A certain address on the scratch region 
SR is set in a scratch pointer SP as a scratch start address. A value of 
the scratch pointer SP can be changed by the user. When the user operates 
the ribbon controller 106 in the scratch mode, the scratch reproduction is 
performed. In this case, when an initial touch is given to the ribbon 
controller 106 at any position, the scratch reproduction is started from 
the start address designated by the scratch pointer SP. 
FIG. 2(e) shows a scratch region prepared in the EX scratch mode. In the EX 
scratch mode, the waveform data from the external source 111 is stored in 
recording buffers SRB0 and SRB1. The recording buffers SRB0 and SRB1 are 
corresponding to the recording buffers RB0 and RB1 explained with 
reference to FIG. 2(b), and are alternately used likewise RB0 and RB1. 
Each of SRB0 and SRB1 has a sufficient memory capacity for performing the 
scratch. For example, when the sampling clock is 40 kHz, the memory 
capacity is capable of storing no less than about 40 k samples. One of 
SRB0 and SRB1 which is not used at a moment when the operation of the 
ribbon controller 106 is started, is set as the scratch region. Since 
there is a recording pointer RP which indicates a writing address in the 
recording buffer SRB0, the data writing is currently performed into SRB0. 
Accordingly, a part of the other recording buffer SRB1 into which the data 
writing is not performed is set as the scratch region SR. Further, a 
certain address in the scratch region SR is set in the scratch pointer SP 
as a scratch start reading address. 
Next, registers other than those shown in FIGS. 2(a)-2(e) will be listed 
below: 
(1) m: an operation mode register. 0 represents the normal mode, 1 the 
sampling mode, 2 the filter mode, 3 the pitch mode, 4 the scratch mode, 5 
the EX filter mode, and 6 the EX scratch mode. 
(2) PN: a register for storing pad numbers for identifying the pads. 
(3) i: a register for storing channel numbers of the channels for assigning 
or allocating thereto tone generation. 
(4) FNi: a register for storing an F number of the i-th channel where tone 
generation is allocated. 
(5) TMP: a register for storing a detection value of the ribbon controller 
106. 
(6) RD: a register used when a detection value from the ribbon controller 
106 is changed for setting that detection value. 
(7) RS: a flag for indicating a state of the ribbon controller 106. When 
the ribbon controller 106 is operated in manner such as a finger or the 
like is in touch with the ribbon controller 106, the flag is set to 1. 
When a finger or the like is not in touch with the ribbon controller 106, 
the flag is set to 0. 
(8) VEL: a register for setting the speed of touch action along the ribbon 
controller 106, specifically, the speed of movement of the finger or the 
like which is in touch with the ribbon controller 106. 
(9) OLD: a register for holding a last detection value of the ribbon 
controller 106. 
(10) SAD: a register for storing a scratch reading address. 
(11) ADi: a register for storing a reading address in the i-th channel 
(i=1-4). 
(12) SFN: a register for storing an F number used when reading out waveform 
data from the scratch channel sch. 
(13) RP: a recording pointer for indicating a writing address of waveform 
data into the recording buffer. 
(14) PP: a reproducing pointer for indicating a reading address of waveform 
data from the reproducing buffer. 
The foregoing symbols showing the registers and the like also represent 
storage regions of the registers and the like, and further represent data 
stored in those storage regions. For example, m represents not only the 
operation mode register but also the data indicative of an operation mode 
stored in that register. 
FIGS. 3 to 16 are flowcharts for explaining operations of the CPU 101 and 
the DMA controller 113 in the sampler of FIG. 1. Hereinbelow, a 
hierarchical structure of the software will be first explained, and then a 
processing procedure of each of the software modules will be explained 
according to the flowcharts of FIGS. 3 to 16. Thereafter, the description 
is given on what timings the software modules are executed so as to 
achieve the function of each mode. 
First, the hierarchical structure of the software is explained. The 
programs shown in FIGS. 3 to 16 are classified as follows: 
level 1: a DR(m) routine of FIG. 15 operating the DMA controller 113 in the 
waveform recording, and a DP routine of FIG. 16 operating the DMA 
controller 113 in the waveform reproduction. 
level 2: waveform generation routines HS(m) of FIGS. 11(a) to 12(c) 
performing waveform preparation by the CPU 101, and ribbon value retrieval 
routines RC(m) of FIGS. 9 and 10 retrieving the detection value of the 
ribbon controller 106 by the CPU 101. Process routines of FIGS. 13(a), 
13(b) and 14 are included here as subroutines of the waveform generation 
routines HS(m). 
level 3: a general routine of FIG. 3 executed by the CPU 101. A pad scan 
routine, a SW scan routine and various event routines of FIGS. 4 to 8 are 
included here as subroutines of the general routine. 
The process routines of level 1 have the highest priority. Specifically, 
when an interruption for executing the process routine of level 1 takes 
place while the process of level 2 or 3 is executed, the process routine 
of level 1 is executed with the highest priority. The processes DR(m) and 
DP of level 1 are not executed by the CPU 101 but executed by the DMA 
controller 113. Thus, when the interruption for the process of level 1 
takes place, the operation of the CPU 101 is stopped while the DMA 
controller 113 holds the bus line 115 so as to execute the process of 
level 1 with the highest priority. The interruption for the process of 
level 1 is timed by the sampling clock Fs. Specifically, the interruption 
takes place every sampling clock Fs so that the DMA controller 113 
executes DP in the waveform reproduction, and DR(m) in the waveform 
recording. Whether DP or DR(m) is executed or not upon the interruption at 
each sampling clock Fs is designated to the DMA controller 113 from the 
CPU 101 in advance. 
The process of level 2 has the priority which is lower than that of the 
process of level 1 but higher than that of the process of level 3. 
Specifically, when an interruption for executing the process of level 2 
takes place while the general routine of level 3 is executed, the process 
routine of level 2 is executed with priority. The DP routine of the DMA 
controller 113 reproduces or reads out the waveform data from the 
reproducing buffer and interrupts the CPU 101 when the reproducing buffer 
becomes vacant. In response to this interruption, the CPU 101 executes the 
waveform generation routine HS(m) and provides next sample values of the 
waveform to the reproducing buffer. The ribbon value retrieval routine 
RC(m) is started by a timer interruption. Specifically, the timer 
interruption takes place every clock outputted from the timer 105 at a 
given interval so that the CPU 101 executes the ribbon value retrieval 
routine RC(m) to take in the detection value of the ribbon controller 106. 
The level 3 represents the process routine having the lowest priority. The 
CPU 101 repeatedly executes the general routine of FIG. 3 and further 
executes the given subroutines upon occurrence of an on-event of the pad 
107 or an operation event of the panel SW 109. 
Next, the operating procedure of the respective software modules will be 
explained according to the flowcharts of FIGS. 3 to 16. FIG. 3 shows the 
general routine of level 3. When the sampler is powered on, the CPU 101 
executes this general routine. First at step 301, various initial settings 
are executed. In particular, the operation mode m is set to the normal 
mode as indicated by m=0, a note-off command is set to all the channels of 
the sound source register of FIG. 2(a), and all the sample regions of the 
reproducing buffers PB0 and PB1 are cleared to zero. During the 
initialization, the CPU 101 instructs the reproducing process to the DMA 
controller 113. In response to this, the DMA controller 113 interrupts the 
CPU 101 every sampling clock Fs from the Fs clock generator 110 and 
executes the DP routine of FIG. 16 upon every interruption so as to start 
the operation of reproducing the waveform data held in the reproducing 
buffer. Further, the timer 105 is started during the initialization. By 
this, the CPU 101 executes the RC retrieval routine RC(m) upon every timer 
interruption based on the clock from the timer 105 so as to start the 
process of retrieving the detection value from the ribbon controller 106. 
Next, a pad scan process is executed at step 302, then an SW scan process 
is executed at step 303, and thereafter the routine returns to step 302 to 
repeat the same processes. The pad scan process of step 302 is carried out 
to detect whether there is any on-event of the ten pads 107, and executes 
the on-event routines shown in FIGS. 7 and 8 when there is the on-event. 
The SW scan process of step 303 is carried out to detect whether operation 
of the panel SW 109 is performed or not, and executes the process routine 
corresponding to that operation when the operation is performed. 
FIG. 4 shows a mode SW event routine which is called upon detection of the 
actuation of the mode change-over switch in the SW scan process of step 
303 in FIG. 3. In the mode SW event routine, a value indicative of the 
operation mode designated depending on the operation of the mode 
change-over switch is set in the register m at step 401, and the display 
108 is controlled according to the designated mode m at step 402. Then, a 
starting process MS(m) corresponding to the designated mode m is executed 
at step 403, and thereafter the process is terminated. 
FIG. 5 is a flowchart of a sampling mode start process MS(1) which is 
called at step 403 in FIG. 4 when the user designates the sampling mode 
(m=1) using the mode change-over switch. In the MS(1) process, first at 
step 501, it is determined whether the designation of a pad is performed. 
If the designation of any pad is not performed, step 502 determines 
whether the designation of the sampling mode is quit or not. If the 
designation of the sampling mode continues, the routine returns to step 
501 so as to urge the designation of the pad. 
If the designation of any pad is effected at step 501, a number of the 
designated pad is stored or reserved in the register PN at step 503, and 
recording preparation is performed at step 504. The recording preparation 
is performed for ensuring the recording buffers RB0 and RB1, the recording 
region on the flash memory 103 and other regions. Further, the DMA 
controller 113 is instructed to stop the execution of the DP routine which 
is executed by interrupting the CPU 101 each sampling clock Fs. Next, at 
step 505, it is determined whether a condition (trigger) for starting the 
recording is satisfied or not. The condition for the start of recording, 
for example, is such that the recording is started when the input level 
becomes no less than a given value. If the condition for the start of 
recording is not satisfied, step 506 determines whether to stop the 
recording. If the recording continues, the routine returns to step 505. 
If the condition for the start of recording is satisfied at step 505, the 
recording is actually started at step 507. The start of recording is, 
specifically, effected by instructing the start of recording to the DMA 
controller 113 from the CPU 101. By this, the DMA controller 113 
interrupts the CPU 101 each sampling clock Fs from the Fs clock generator 
110, and executes the DR(1) routine of FIG. 15 upon every interruption so 
as to start a process of setting the waveform data inputted from the 
external source 111 into the recording buffer RBk via the input FIFO in 
the sound I/O 112. 
Next, at step 508, it is determined whether the recording buffer is filled 
up. As will be explained in detail with reference to FIG. 15, in the DR(1) 
routine, the waveform samples of the external source are transferred to 
the recording buffer RBk. When RBk is filled up, k is inverted to cause 
the interruption. Step 508 awaits this interruption and determines whether 
the recording buffer is filled up. If the interruption takes place, this 
means that the recording buffer RBk is filled with the waveform samples. 
Thus, the waveform samples of the recording buffer RBk are written into a 
predetermined region of the flash memory 103 at step 509, and thereafter 
the routine returns to step 508. 
If the recording buffer is not filled up (no interruption from the DR(1) 
routine) at step 508, step 510 determines whether to finish the recording 
process. The recording process is finished upon an on-event of a recording 
stop switch of the panel SW 109 or when the recording region ensured in 
the flash memory 103 is filled up. If it is judged that the recording 
process should not finish at step 510, the routine returns to step 508 to 
continue the recording. If it is judged that the recording process should 
finish at step 510, the recording finish process is executed at step 511 
by instructing the DMA controller 113 to stop the execution of the DR(1) 
routine. Then, at step 512, the register m is set to 0 to return to the 
normal mode, and the process is finished. In return to the normal mode, 
the DMA controller 113 is instructed to start the execution of the DP 
routine by interrupting the CPU 101 per sampling clock Fs. In similar 
manner, if the sampling mode start process is quit at step 502, the 
register m is set to 0 to thereby return to the normal mode at step 513, 
and then the process is finished. Further, if the recording process is 
quit at step 506, the register m is set to 0 to thereby return to the 
normal mode at step 514, and then the process is finished. Process at 
steps 513, 514 is the same as that of step 512. 
FIG. 6 is a flowchart of the scratch mode start process MS(4) which is 
called at step 403 in FIG. 4 when the user designates the scratch mode 
(m=4) using the mode change-over switch. In the MS(4) process, first at 
step 601, it is determined whether the designation of a pad is performed 
or not. If the designation of any pad is not performed, step 602 
determines whether to quit the designation of the scratch mode. If the 
designation process of the scratch mode should be continued, the routine 
returns to step 601 so as to urge the designation of the pad. 
If the designation of any pad is performed at step 601, a number or code of 
the designated pad is reserved in the register PN at step 603. Then, 
preparation for performing the scratch is made at step 604. This is a 
process of reading out the waveform data recorded corresponding to the pad 
number PN from the flash memory 103, ADPCM-expanding the read waveform 
data and developing the expanded waveform data in a given region of the 
RAM 104. Then at step 605, a desired part of the waveform data developed 
in the given region of the RAM 104 is set to be the scratch region SR 
(FIG. 2(d)), and the scratch pointer SP representing an address of 
starting the scratch is set to a predetermined value. If the scratch mode 
designating process is quit at step 602, the register m is set to 0 to 
thereby return to the normal mode at step 606, and the process is 
finished. 
FIG. 7 shows a flowchart of the pad on-event routine which is called upon 
detection of the on-event of the pads 107 at step 302 in FIG. 3 when the 
mode m is set to the normal mode, the filter mode or the scratch mode 
(m=0, 2, 4). In this on-event routine, first at step 701, a pad number of 
the pad 107 where the on-event occurs is set in the register PN. Then, 
step 702 determines whether the waveform data corresponding to the pad 
number PN is reserved on the flash memory 103. If there is no waveform 
data corresponding to the pad number PN, the process is finished. If the 
waveform data corresponding to the pad number PN is found at step 702, 
allocation or assignment of the tone generation channel is performed at 
step 703. This channel allocation is performed within the maximum number 
of tone generations depending on the mode m. Specifically, in the normal 
mode, since four tones can be concurrently generated at most, if there is 
a vacant channel in the first to fourth channels, each tone generation is 
allocated to that vacant channel. On the other hand, if all the four 
channels are used for tone generation, the tone generation is ceased in 
the oldest channel where the tone generation is started from the oldest 
time point, and another tone generation is newly allocated to that 
channel. In the filter mode or the scratch mode, since two tones can be 
concurrently generated at most, each tone generation is allocated to the 
first or second channel in a similar fashion. A number of the allocated 
channel is set in the register i. Subsequently, at step 704, various data 
for performing the tone generation including a head address ADi of 
waveform data to be reproduced are set in the sound source register ich of 
the i-th channel. The note-on command is further set and the process is 
finished. 
FIG. 8 shows a flowchart of the pad on-event routine which is called upon 
detection of the on-event of the pads 107 at step 302 in FIG. 3 when the 
mode m is set in the pitch mode (m=3). In the pad on-event routine, first 
at step 801, a pad number of the pad 107 where the on-event occurs is set 
in the register PN. Then, the tone generation channel allocation is 
performed at step 802. In the pitch mode, since two tones can be 
concurrently generated at most, the channel allocation is performed within 
the maximum tone generation number 2. Then, at step 803, the pad number PN 
is converted into a corresponding F number which is set in the register 
FNi. Subsequently, at step 804, various data including a start address of 
reading waveform data to be reproduced and F number FNi are set for 
achieving the reproduction of the musical tone with a pitch shift in the 
sound source register ich of the i-th channel. The note-on command is 
further set, and thereafter the process is finished. In this process, one 
pad 107 is depressed to designate a desired waveform, and to concurrently 
specify a corresponding F number, which is set to the sound source 
register ch to determine a pitch applied to the reproduced tone. 
FIG. 9 is a flowchart of the RC retrieval routine RC(m) for taking in the 
detection value of the ribbon controller 106 when the mode m is set in the 
filter mode or the EX filter mode (m=2 or 5). This is a process of taking 
in the detection value for performing the filter control by the ribbon 
controller 106. FIG. 10 is a flowchart of the RC retrieval routine RC(m) 
for taking in the detection value of the ribbon controller 106 when the 
mode m is set in the scratch mode or the EX scratch mode (m=4 or 6). This 
is a process of taking in the detection value for performing the scratch 
control by the ribbon controller 106. The timer 105 is started during the 
initialization at step 301 in FIG. 3. The CPU 101 executes the timer 
interruption at a given time interval. The RC retrieval routine RC(m) of 
FIG. 9 is executed when the mode m is set to 2 or 5 by the timer 
interruption. On the other hand, the other RC retrieval routine RC(m) of 
FIG. 10 is executed when the mode m is set to 4 or 6 by the timer 
interruption. 
The RC retrieval routine RC(m) (m=2, 5) of FIG. 9 is first explained. First 
at step 901, the detection value of the ribbon controller 106 is set in 
the register TMP. Subsequently, at step 902, it is determined whether a 
succeeding detection value changes as compared to a preceding detection 
value retrieved at the last timer interruption. If there is no change, the 
process is finished. If there is a change, the detection value TMP is set 
in the register RD at step 903 and the process is finished. As a result, 
the detection value of the ribbon controller 106 is set in the register 
RD. If a finger or the like is removed from the ribbon controller 106, the 
detection value TMP and RD may be returned to a default value, or the 
value immediately before the removal of the finger or the like may be 
held. 
The RC retrieval routine RC(m) (m=4, 6) of FIG. 10 will be explained. FIG. 
10 is a flowchart for explaining both of the RC retrieval routine RC(4) 
which is called when the operation mode is set to the scratch mode (m=4), 
and the RC retrieval routine RC(6) which is called when the operation mode 
is set to the EX scratch mode (m=6). Since steps 1006, 1009, 1015 and 1016 
represent processes only for the RC(6), the operation procedure of the 
RC(4) will be first explained and then the operation procedure of the 
RC(6) will be explained hereinbelow. 
In the ribbon controller detection value retrieval routine RC(4), first at 
step 1001, the detection value of the ribbon controller 106 is set in the 
register TMP. Then at step 1002, it is determined whether the ribbon 
controller 106 is operated. The ribbon controller 106 outputs a coordinate 
detection value indicative of a coordinate position where a finger, a rod 
or the like is touched, while the ribbon controller 106 outputs a default 
value when the finger, the rod or the like is not in touch so that the 
non-touch (the non-operation) can be recognized. When the ribbon 
controller 106 is not operated, the routine proceeds to step 1003. When 
the ribbon controller 106 is operated, the routine proceeds to step 1004. 
At step 1003, it is determined whether the status register RS of touch 
action is 0 or not. If the register RS is 0, this means that the ribbon 
controller 106 is not operated both in the last interruption and in the 
current interruption. Thus, the process is finished. If RS is not 0 at 
step 1003, this means that the ribbon controller 106 has been operated in 
the last interruption while the ribbon controller 106 is not operated (the 
finger, the rod or the like is removed) in the current interruption. Thus, 
the register RS is cleared to 0 at step 1013, the note-off command is 
written in the sound source register sch of the scratch channel at step 
1014, and the process is finished. 
At step 1004, it is determined whether the register RS is 1 or not. If the 
register RS is not 1, this means that the ribbon controller 106 has not 
been operated in the last interruption while the ribbon controller 106 is 
operated in the current interruption. Thus, the register RS is set to 1 at 
step 1005 and the velocity VEL is set to 0. Then at step 1007, a reading 
address SAD is set to a predetermined value of the scratch pointer SP. 
Next, at step 1008, various data for the scratch reproduction including a 
reading address of waveform data to be scratch-reproduced and a velocity 
value VEL are set, and the note-on command is written in the sound source 
register sch of the scratch channel. Subsequently, at step 1010, the 
current detection value TMP of the ribbon controller 106 is set in the 
register OLD, and the process is finished. 
If the check result is YES at step 1004, this means that RS=1 in the last 
interruption and also RS=1 in the current interruption (the operation of 
the ribbon controller 106 is continued). Thus, the velocity of the touch 
action on the ribbon controller 106 is detected and set in the register 
VEL at step 1011. The velocity VEL is derived through differential 
computation by subtracting the detection value OLD in the last 
interruption from the current detection value TMP. Thus, it is possible 
that the velocity VEL takes a negative value. Further, the velocity VEL is 
set in the sound source register sch of the scratch channel. Then, at step 
1012, the current detection value TMP is set in the register OLD, and the 
process is finished. 
Explanation has been made to the RC retrieval or take-in routine RC(4) when 
the mode is set to the scratch mode (m=4). In the RC take-in routine RC(6) 
when the mode is set to the EX scratch mode (m=6), step 1006 is added 
after step 1005, step 1009 is added after step 1008, and steps 1015 and 
1016 are added after step 1014. Further, processes at steps 1008 and 1014 
are somewhat different. Hereinbelow, explanation will be made therefor. At 
the time of starting the operation of the ribbon controller 106, the 
routine proceeds from step 1004 to step 1006 via step 1005. At step 1006, 
the CPU 101 instructs the DMA controller 113 to stop the execution of the 
RD(6) routine by interrupting the CPU 101 per sampling clock Fs, and the 
scratch region SR is set in the recording buffer SRBk which is one of the 
two recording buffers SRB0 and SRB1 currently not used, as explained with 
reference to FIG. 2(e). Then, the routine proceeds to step 1008 via step 
1007. At step 1008, various data for the scratch reproduction including a 
reading address SAD of waveform data to be scratch-reproduced and velocity 
value VEL are set and the note-on command is written in the sound source 
register sch of the scratch channel. Further, at step 1008, the following 
process is also performed before the foregoing process. Specifically, 
first, 128 samples of one waveform are provided in the reproducing buffer 
PBr. In this process, after clearing the reproducing buffer PBr to 0, the 
later-described EX scratch process of FIG. 14 may be performed relative to 
the reproducing buffer PBr (PBr is used instead of PBr in FIG. 14). 
Further, the CPU 101 instructs the DMA controller 113 to restart the 
execution of the DP routine by interrupting the CPU 101 per sampling clock 
Fs. Further, an interruption of the same significance as a later-described 
interruption caused at step 1605 of the DP routine in FIG. 16 is 
generated. Through this interruption, the HS(6) is executed so that next 
128 samples to be scratch-reproduced are provided in the PBr. Thereafter, 
at step 1009, under the command from the CPU 101, the direct connection 
from the A/D input to the D/A output of the sound I/O 112 is disabled so 
as to stop the sound emission of feeding the musical tone signal from the 
external source 111 directly to the sound system 114. 
At the time of stopping the operation of the ribbon controller 106, the 
routine proceeds from step 1002 to step 1014 via steps 1003 and 1013. At 
step 1014, the note-off event is written in the sound source register sch 
of the scratch channel, and then the following process is also performed. 
Specifically, the CPU 101 instructs the DMA controller 113 to stop the 
execution of the DP routine of interrupting the CPU 101 per sampling clock 
Fs. On the other hand, at step 1015, under the command of the CPU 101, the 
direct connection from the A/D input to the D/A output of the sound I/O 
112 is restored so as to achieve the sound emission by feeding the musical 
tone signal from the external source 111 directly to the sound system 114. 
At step 1016, the CPU 101 instructs the DMA controller 113 to restart the 
execution of the DP(6) routine by interrupting the CPU 101 per sampling 
clock Fs. 
FIGS. 11(a) to 11(c) and FIGS. 12(a) to 12(c) are flowcharts of the 
waveform generation routine HS(m) executed by the CPU 101 for providing 
sequential sample values of the waveform to the reproducing buffer under 
the respective modes m. The waveform generation routine HS(m) is executed 
by the CPU 101 in response to a later-described interruption demand at 
step 1605 of the DP routine in FIG. 16. Specifically, in the DP routine, 
one sample value of the waveform held in the reproducing buffer PBr is 
transferred to the sound I/O 112 each sampling clock Fs so as to perform 
the reproduction of the musical tone. When the set of 128 sample values in 
the reproducing buffer PBr are all reproduced, the DP routine inverts k so 
as to cause an interruption. Upon this interruption as a trigger, the CPU 
101 executes the waveform generation routine HS(m) depending on the mode 
m, and newly produces another set of 128 sample values corresponding to 
one frame of the reproducing buffer PBr which has just finished the 
reproduction and rendered vacant. 
FIG. 11(a) is a flowchart of the waveform generation routine HS(0) for 
generating the waveform sample values on the reproducing buffer under the 
normal mode. In HS(0), a subroutine denoted "normal 4" is called at step 
1101, and the process is finished. This subroutine will be described later 
with reference to FIG. 13(a). 
FIG. 11(b) is a flowchart of the waveform generation routine HS(2) for 
generating the waveform sample values on the reproducing buffer under the 
filter mode. In HS(2), a subroutine "normal 2" is called at step 1111, and 
a filter coefficient (cut-off frequency) is produced according to the 
detection value RD of the ribbon controller 106 at step 1112. Then at step 
1113, the filter process (low-pass filter process) is performed, and the 
process is finished. The "normal 2" at step 1111 will be described later 
with reference to FIG. 13(a). 
FIG. 11(c) is a flowchart of the waveform generation routine HS(3) for 
generating the waveform sample values on the reproducing buffer under the 
pitch mode. In HS(3), a subroutine "pitch 2" is called at step 1121, and 
the process is finished. The "pitch 2" will be described later with 
reference to FIG. 13(b). 
FIG. 12(a) is a flowchart of the waveform generation routine HS(4) for 
generating the waveform sample values on the reproducing buffer under the 
scratch mode. In HS(4), the subroutine of the "normal 2" is called at step 
1201, then a scratch process subroutine is called at step 1202, and the 
process is finished. The "normal 2" will be described later with reference 
to FIG. 13(a). The scratch process subroutine will be described later with 
reference to FIG. 14. 
FIG. 12(b) is a flowchart of the waveform generation routine HS(5) for 
generating the waveform sample values on the reproducing buffer under the 
EX filter mode. When HS(5) is called, the set of 128 samples (linear 
samples) of the waveform data fed from the external input 111 are written 
in the recording buffer RBk, while the reproducing buffer PBr is vacant. 
Accordingly, in HS(5), first at step 1211, a filter coefficient is 
produced according to the detection value RD of the ribbon controller 106, 
and an EX filter process is performed at step 1212. This EX filter process 
is called for applying the filtering process using the filter coefficient 
derived at step 1211 to the set of 128 waveform samples held in the 
recording buffer RBk, and for setting the resultant 128 waveform samples 
in the reproducing buffer PBr. After step 1212, the process is finished. 
FIG. 12(c) is a flowchart of the waveform generation routine HS(6) for 
generating the waveform samples in the reproducing buffer under the EX 
scratch mode. In HS(6), step 1221 determines whether the register RS is 1 
or not. If the register RS is not 1, this means that the ribbon controller 
106 is not operated. Thus, the process is finished. If the register RS is 
1 at step 1221, this means that the ribbon controller 106 is operated. 
Thus, an EX scratch process is performed at step 1222, and the process is 
finished. The EX scratch process will be described later with reference to 
FIG. 14. 
FIG. 13(a) shows a flowchart of the normal n. The normal 4 is called at the 
foregoing step 1101, while the normal 2 is called at the foregoing steps 
1111 and 1201. First at step 1301, a work register i for counting the 
channels is set to 1, a work register j for counting the samples is set to 
0, and all the sample region of the reproducing buffer PBr which is not 
currently subjected to the DP routine are cleared to 0. Then at step 1302, 
it is determined whether the note-on is written in the sound source 
register ich of the i-th channel. If the note-on is not written, it is not 
necessary to perform the waveform generation of the i-th channel. Thus, 
the routine proceeds to step 1308. If the i-th channel is subjected to the 
note-on event at step 1302, the routine proceeds to step 1303. 
At step 1303, the reading address ADi of the i-th channel (ADi is set in 
the sound source register ich of the i-th channel) is incremented. At step 
1304, the waveform sample is read out from the address ADi via the i-th 
channel, and the read waveform sample is ADPCM-expanded to derive a linear 
waveform sample which is then set in the work register TMP. Subsequently, 
at step 1305, the value of the register TMP is accumulated (channel 
accumulation) in the reproducing buffer PBr(j) as represented by 
PBr(j)+TMP.fwdarw.PBr(j). 
Then at step 1306, it is determined whether the count of the register j 
reaches 127. If the register j does not reach 127, the register j is 
incremented at step 1307 and the routine returns to step 1303 so as to 
repeat reading of the next waveform sample, the expansion and the 
accumulation. If the count of the register j becomes 127 at step 1306, 
meaning that the accumulation or summing-up of the 128 samples of the i-th 
channel is finished in the region assigned to the 128 samples of the 
reproducing buffer PBr, the routine proceeds to step 1308. 
At step 1308, it is determined whether the register i reaches n. If the 
register i does not reach n, the register i is incremented and the 
register j is cleared to 0 at step 1309 for commencing the waveform 
processing of the next channel. Then, the routine returns to step 1302 to 
repeat the processes relative to the i-th channel. If the register i 
reaches n at step 1308, meaning that the summing-up computation in the 
last channel is finished and 128 samples are produced in the reproducing 
buffer PBr, the process is finished. 
FIG. 13(b) is a flowchart of the "pitch 2" subroutine which is called at 
step 1121 in FIG. 11(c). At step 1311, the work register j for counting 
the channels is set to 1, the work register j for counting the samples is 
set to 0, and all the sample regions of the reproducing buffer PBrwhich is 
not currently subjected to the DP routine are cleared to 0. Then at step 
1312, it is determined whether the note-on is written to the sound source 
register ich of the i-th channel. If the note-on is not written, it is not 
necessary to perform the pitch-shifted waveform generation of the i-th 
channel. Thus, the routine proceeds to step 1319. If the i-th channel is 
subjected to the note-on event at step 1312, the routine proceeds to step 
1313. 
At step 1313, the waveform sample reading address ADi is added with the F 
number FNi so as to set a new address ADi. ADi and FNi are set in the 
sound source register ich of the i-th channel. Then, at step 1314, the 
waveform sample is read out from the address ADi via the i-th channel, and 
is ADPCM-expanded to derive the linear waveform sample which is then set 
in the work register TMP. Since the read waveform data is 
ADPCM-compressed, if an integer portion of the address ADi advances by no 
less than 2 as the result of the addition of the F number, all the samples 
from the last reading address to the current reading address ADi are read 
out and used for the linear expansion. Subsequently, at step 1315, the 
interpolation among the read samples is performed depending on a decimal 
portion of the address ADi, and the interpolated waveform sample is set in 
the register TMP. Then, at step 1316, the derived waveform sample TMP is 
accumulated in the j-th sample region PBr(j) of the reproducing buffer. 
Then, at step 1317, it is determined whether the register j reaches 127. If 
not, the register j is incremented at step 1318 and the routine returns to 
step 1313 so as to perform the processes relative to the next sample. If 
the register j reaches 127 at step 1317, meaning that the process for the 
i-th channel is finished, step 1319 determines whether the register i 
reaches 2. If the register i does not reach 2, the register i is 
incremented and the register j is cleared to 0 at step 1320, and then the 
routine returns to step 1312 so as to perform the processes relative to 
the next channel. If the value of the register i reaches 2 at step 1319, 
the process is finished. FIG. 14 is a flowchart of the scratch process 
which is called at step 1202 in FIG. 12(a) and the EX scratch process 
which is called at step 1222 in FIG. 12(c). First at step 1401, the 
detected touch action velocity VEL (VEL is provided in the sound source 
register sch of the scratch channel) of the ribbon controller 106 is 
converted into a variable F number SFN for the scratch operation. Since 
the F number SFN is determined depending on the velocity VEL which may 
take either of a positive value and a negative value, the F number SFN 
also changes in the positive and negative directions. Next, the register j 
is cleared to 0 at step 1402, and the routine proceeds to step 1403. 
At step 1403, the scratch F number SFN is added to the scratch reading 
address SAD which is set in the sound source register sch of the scratch 
channel. At step 1404, the waveform sample is read out from the address 
SAD, and is set in the register TMP. In the scratch process called at step 
1202 in FIG. 12(a), the read waveform data is ADPCM-expanded and developed 
in a given region in advance, and the scratch region SR is set in the 
given region where the waveform data is developed (steps 604 and 605 in 
FIG. 6). On the other hand, in the EX scratch process called at step 1222 
in FIG. 12(c), the waveform data composed of a sequence of linear samples 
are inputted from the external source 111 and are written alternately into 
the recording buffers SRB0 and SRB1, and the scratch region SR is set in 
either of the recording buffers SRB0 and SRB1 which is not subjected to 
writing of the waveform data at the time of starting of the operation of 
the ribbon controller 106 (step 1007 in FIG. 10). In either case, only the 
number of samples as required for the interpolation is read out at step 
1404. 
Next, at step 1405, the interpolation among the read samples is performed 
depending on a decimal portion of the address SAD, and the interpolated 
waveform sample is set in the register TMP. Then at step 1406, the 
waveform sample TMP is accumulated in the j-th sample region PBr(j) of the 
reproducing buffer PBr to produce the absolute sample value represented by 
PBr+TMP. Next, at step 1407, it is determined whether the register j 
reaches 127. If the register j does not reach 127, the register j is 
incremented at step 1408 and the routine returns to step 1403 so as to 
perform the processes relative to the next sample. If the register j 
reaches 127 at step 1407, the process is finished. 
FIG. 15 is a flowchart of the DR(m) routine executed by the DMA controller 
113 per sampling clock Fs generated by the Fs clock generator 110. The 
recording is performed when mode m=1, 5 or 6. First at step 1501, the 
waveform sample is transferred from the input FIFO of the sound I/O 112 to 
the sample region PBk(RP) of the recording buffer PBk designated by the 
recording pointer RP. The original musical tone signal inputted into the 
A/D input terminal from the external source 111 is A/D converted and 
loaded into the input FIFO. When the mode m is the sampling mode (m=1), 
the linear waveform sample A/D converted by the A/D converter is 
ADPCM-compressed using the ADPCM compression function of the sound I/O 
112, and the compressed waveform sample is transferred to the recording 
buffer RBk(RP) via the input FIFO. On the other hand, when the mode m is 
the EX filter mode (m=5) or the EX scratch mode (m=6), the linear waveform 
sample which is A/D converted and is not subjected to the ADPCM 
compression is transferred to the recording buffer PBk(RP) via the input 
FIFO. When m=6, the recording buffer SRBk(RP) is used instead of the 
recording buffer RBk(RP). 
Subsequently, the recording pointer RP is incremented at step 1502. Step 
1503 determines whether the recording buffer RBk (when m=6, SRBk, which is 
also applied hereinafter) is filled up. If not filled up, the process is 
finished. If the recording buffer RBk is filled up, k is inverted (if 0, 
then converted to 1 and, if 1, then converted to 0) at step 1504. The 
interruption is generated at step 1505, and the process is finished. This 
interruption is caused for requesting the CPU 101 to perform a process of 
writing the set of the waveform samples of the filled-up recording buffer 
(RBk at this time point) into the flash memory 103 so as to render the 
recording buffer vacant. 
FIG. 16 is a flowchart of the DP routine executed by the DMA controller 113 
per sampling clock Fs generated by the Fs clock generator 110. First at 
step 1601, the waveform sample PBr(PP) indicated by the reproducing 
pointer PP on the reproducing buffer PBr is transferred to the output FIFO 
of the sound I/O 112. As explained with reference to FIG. 1, the waveform 
sample stored in the output FIFO is D/A converted, and is then sent to the 
sound system 114 so as to sound the musical tone. Next, the reproducing 
pointer PP is incremented at step 1602. Step 1603 determines whether the 
last one of the samples of the reproducing buffer PBr is sent out. 
If all the waveform samples of the reproducing buffer PBr are reproduced at 
step 1603, r is inverted (if 0, then converted to 1 and, if 1, then 
converted to 0) and the other reproducing buffer is selected to be read 
out next at step 1604. Then at step 1605, an interruption is generated for 
requesting next provision of the waveform samples to the CPU 101, and the 
process is finished. If, at step 1603, there remains the waveform sample 
on the reproducing buffer PBr which is not reproduced yet, the process is 
once finished. 
Next, description is given on what timings the foregoing flowcharts are 
executed in the respective mode. First, the operation in the normal mode 
(m=0) will be explained. When the normal mode is designated by the user 
using the mode change-over switch, the register m is set to 0 in the 
foregoing mode SW event routine shown in FIG. 4. Since the normal mode 
start process MS(0) does not perform any significant process to be 
explained in particular, its flowchart is omitted. On the other hand, when 
the operation of executing the DP routine per sampling clock Fs is stopped 
by the EX scratch mode or the like, MS(0) restarts its operation. 
During the initialization at step 301 in FIG. 3 or in the restarting 
process of the reproducing operation by means of the foregoing MS(0), the 
CPU 101 sets the sound source registers of all the channels in FIG. 2(a) 
to the note-off state, clears all the sample regions of the reproducing 
buffers PB0 and PB1 of FIG. 2(c) to 0, instructs the sound I/O 112 and the 
DMA controller 113 to perform the reproducing operation, and then starts 
the generation of the sampling clock Fs by the Fs clock generator 110. By 
this, the DMA controller 113 interrupts the CPU 101 per sampling clock Fs 
from the Fs clock generator 110 and executes the DP routine of FIG. 16 
upon every interruption so as to start the operation of reproducing the 
waveform data in the reproducing buffer. 
Now, a timing of process upon the reproduction will be explained. FIG. 
17(a) shows a timing chart upon the reproduction. Each of sections S1 to 
S5 represents a frame for executing the reproduction of a set of the 128 
samples. In the figure, "waveform generation by CPU" represents a section 
where the CPU 101 executes the waveform generation routine HS(0) of FIG. 
11(a) so as to perform the process of generating 128 samples to be 
reproduced next in the reproducing buffer PB0 or PB1. On the other hand, 
"DP routine of DMAC" represents a section for performing the process of 
executing the DP routine so as to reproduce the waveform data in the 
reproducing buffer. The DP routine is executed per interruption depending 
on the sampling clock Fs, and the interruption takes place 128 times at a 
regular interval within one frame. Numerals 0 to 4 assigned to each of 
"waveform generation by CPU" and "DP routine of DMAC" are numerals 
assigned for convenience for indicating orders of the waveform generation 
and the reproduction. 
In FIG. 17(a), first at section S1, the CPU 101 executes HS(0) and 
generates or produces the waveform data (128 waveform samples) for the 
reproducing buffer PB0. At subsequent section S2, the DMA controller 113 
executes the DP routine based on the interruption per sampling clock Fs. 
By this, the 128 waveform samples of the reproducing buffer PB0 generated 
at section S1 are transferred to the output FIFO of the sound I/O 112 and 
reproduced in sequence at section S2. At the time point where all the 128 
waveform samples of the reproducing buffer PB0 are transferred to the 
output FIFO of the sound I/O 112 (at termination of section S2), the 
interruption takes place (step 1605). Upon this interruption as a trigger, 
the CPU 101 executes the waveform generation routine HS(0) at section S3 
and generates new waveform data (128 waveform samples) for the reproducing 
buffer PB0. 
The foregoing explanation has been made only with respect to the 
reproducing buffer PB0. PB1 is also used alternately with PB0. To sum up, 
the DP routine is executed based on the interruption per sampling clock Fs 
so as to perform the reproduction of the waveform samples of PB0 and PB1 
alternately with each other in such a manner: reproducing the waveform 
samples of PB1 at section S1, reproducing the waveform samples of PB0 at 
section S2, reproducing the waveform samples of PB1 at section S3, 
reproducing the waveform samples of PB0 at section S4, and so on. HS(0) is 
executed based on the interruption caused at the time point where the 128 
samples are reproduced at each section, and the next 128 samples are 
produced for one of PB0 or PB1 which is currently idling. In view of the 
hierarchical structure of the software, the DP routine belongs to level 1, 
while HS(0) belongs to level 2. Thus, if an interruption is caused 
following sampling clock Fs while HS(0) is executed, the DP routine is 
executed with priority. By this, the reproduction by means of the DP 
routine and the waveform generation by means of the waveform generation 
routine HS(O) can be performed in parallel with each other. 
If the pad is not depressed in the normal mode (m=0), all 0 samples in the 
reproducing buffer PB0, PB1 are repeatedly reproduced at timings explained 
with reference to FIG. 17(a). Because of the reproduction of all 0 
samples, it is actually the same as a case where no musical tone is 
generated. The process will be explained wherein the pad is tapped in this 
state. As shown by arrows of "pad" in FIG. 17(a), it is assumed that the 
pad is set on at section S1. If the pad-on is detected in the general 
routine, the note-on of the waveform data corresponding to the set-on pad 
is written in the sound source register of FIG. 2(a) through the on-event 
routine of FIG. 7. The general routine or the on-event routine belongs to 
level 3 so as to be operated in parallel to the waveform generation 
routine HS(0) and the DP routine. The note-on written in the sound source 
register is treated for the reproducing buffer in the next execution of 
the HS(0). 
Next, the operation in the sampling mode (m=1) will be explained. When the 
sampling mode is designated by the user using the mode change-over switch, 
the register m is set to 1 in the foregoing mode SW event routine of FIG. 
4. Further, the sampling mode start process MS(1) is executed as shown in 
FIG. 5. In MS(1), the DP routine is stopped and the sound I/O 112 and the 
DMA controller 113 are instructed to perform the recording operation. By 
this, the DMA controller 113 interrupts the CPU 101 per sampling clock Fs 
fed from the Fs clock generator 110 and executes the DR(1) routine of FIG. 
15 upon every interruption so as to start the operation of recording the 
waveform sample from the external source into the recording buffer. 
Now, the timing of the process upon recording will be explained. FIG. 17(b) 
shows a timing chart upon recording. Each of sections S1 to S5 represents 
a frame for executing the recording of a set of 128 samples. In the 
figure, "DR routine of DMAC" represents a section for performing a 
recording process of executing the DR(1) routine so as to write the 
waveform samples of the input FIFO of the sound I/O 112 into the recording 
buffer. The waveform sample is obtained by A/D converting the external 
input signal and is ADPCM-compressed. The DR(1) routine is executed based 
on the interruption per sampling clock Fs, and this interruption is 
generated 128 times at a regular interval within on frame. In the figure, 
"writing into flash memory by CPU" represents a section for performing a 
process where the CPU 101 writes the waveform samples of the recording 
buffer RB0 or RB1 into the flash memory 103 so as to render the recording 
buffer vacant at step 509 in FIG. 5. Numerals 0 to 4 assigned to each 
section are numerals assigned for convenience for indicating orders of the 
recording and the writing into the flash memory. 
In FIG. 17(b), first at section S1, the interruption is caused per sampling 
clock Fs and the DMA controller 113 executes the DR(1) routine upon every 
interruption. By this, the waveform samples of the input FIFO of the sound 
I/O 112 are written into the recording buffer RB0 in sequence. At the time 
point where the 128 waveform samples are written into the recording buffer 
RB0 at termination of section S1, an interruption takes place (step 1505). 
Upon this interruption as a trigger, the CPU 101 writes the waveform 
samples of the recording buffer RB0 into the flash memory 103 at section 
S2 (step 509) so as to render the recording buffer RB0 vacant. 
The foregoing explanation has been made only with respect to the recording 
buffer RB0. RB1 is also used alternately with RB0. To sum up, the DR(1) 
routine is executed based on the interruption per sampling clock Fs so as 
to perform the recording or writing of the waveform samples into RB0 and 
RB1 alternately with each other according to the sampling clock Fs in such 
a manner: recording the waveform samples into RB0 at section S1, recording 
the waveform samples into RB1 at section S2, recording the waveform 
samples into RB0 at section S3, and so on. Based on the interruption 
caused at the time point where 128 samples are recorded in each section, 
the waveform samples of the recording buffer which completes the recording 
are written into the flash memory 103. In view of the hierarchical 
structure of the software, the DR(1) routine belongs to level 1, while 
MS(1) belongs to level 3. Thus, if an interruption is caused following 
sampling clock Fs while MS(1) is executed, the DR(1) routine is executed 
with priority. By this, the recording by means of the DR(1) routine and 
the writing into the flash memory 103 by means of MS(1) can be performed 
in parallel with each other. 
Next, the operation in the filter mode (m=2) will be explained. When the 
filter mode is designated by the user using the mode change-over switch, 
the register m is set to 2 in the foregoing mode SW event routine shown in 
FIG. 4. Since the filter mode start process MS(2) does not perform any 
significant process to be explained in particular, its flowchart is 
omitted. On the other hand, when the operation of executing the DP routine 
per sampling clock Fs is stopped by the EX scratch mode or the like, MS(2) 
restarts its reproducing operation likewise the normal mode start process 
MS(0). 
The filter mode performs the reproduction in a manner essentially the same 
as that of the normal mode. The DP routine is executed per sampling clock 
Fs and all 0 samples in the reproducing buffer PB0, PB1 are repeatedly 
reproduced while the pad-on is not achieved, which are the same as in the 
normal mode, and a processing procedure upon pad-on is also the same. 
Further, the timing upon reproduction is also the same as in FIG. 17(a). 
However, in the filter mode, the RC take-in routine RC(2) of FIG. 9 is 
executed each given timing based on the timer interruption so as to take 
in the detection value of the ribbon controller 106, and HS(2) of FIG. 
11(b) is set, instead of HS(0), as the waveform generation process of the 
CPU 101 in FIG. 17(a). In the waveform generating routine HS(2), the 
waveform samples of at most two tones based on the pad-on are accumulated 
in the reproducing buffer, and the filter process is performed with the 
filter coefficient depending on the detection value RD of the ribbon 
controller 106 relative to the waveform samples of the reproducing buffer 
(steps 1112 and 1113). In the foregoing fashion, the filter control of the 
reproduced tone by the ribbon controller 106 is performed. 
In the filter mode, the number of tone generations is reduced from four of 
the normal mode to two. In place of the reduction in number of the 
generated musical tones, the filter process is applied to the reproduced 
waveform. Since a given number of tone generations should be performed 
within a one-frame time, although the four tones can be generated in the 
normal mode, a process time becomes insufficient when the filter process 
is applied to the generated tones. In this regard, the number of tone 
generations is reduced to two so as to shorten the process time for the 
waveform generation, while the additional filter process is performed in a 
remaining time. 
Next, the operation in the pitch mode (m=3) will be explained. When the 
pitch mode is designated by the user using the mode change-over switch, 
the register m is set to 3 in the foregoing mode SW event routine shown in 
FIG. 4. Since the pitch mode start process MS(3) does not perform any 
specific process to be explained in particular, its flowchart is omitted. 
On the other hand, when the operation of executing the DP routine per 
sampling clock Fs is stopped by the EX scratch mode or the like, MS(3) 
restarts its reproducing operation likewise the normal mode start process 
MS(0). 
The pitch mode performs the tone reproduction in a manner essentially the 
same as that of the normal mode. The DP routine is executed per sampling 
clock Fs and all 0 samples in the reproducing buffer PB0, PB1 are 
repeatedly reproduced while the pad-on is not achieved, which are the same 
as in the normal mode, and a processing procedure upon pad-on is also the 
same. Further, the timing upon reproduction is also the same as in FIG. 
17(a). However, in the pitch mode, the pad-on event routine of FIG. 8 is 
used instead of that of FIG. 7, and the waveform generating routine of 
HS(3) of FIG. 11(c) is used instead of that of HS(0) of FIG. 11(a). In the 
pad-on event routine of FIG. 8, the F number FNi corresponding to the pad 
number PN is generated. In the waveform generating routine HS(3) of FIG. 
11(c), the waveform sample is read out using the address which is the sum 
of the F number FNi and the address ADi so as to change the reading speed. 
By this, the reproduction with a desired pitch can be achieved. 
In the pitch mode, the number of tone generations is reduced from four of 
the normal mode to two. In place of the reduction in number of the 
generated musical tones, the pitch shift process is applied to the 
reproduced waveform. Since a given number of tone generations should be 
performed within a one-frame time, although four tones can be generated in 
the normal mode, a process time becomes insufficient when the pitch shift 
process is applied to the generated tones. In this regard, the number of 
tone generations is reduced to two so as to shorten a process time for the 
waveform generation, and the pitch shift process is performed in a 
remaining time. 
Next, the operation in the scratch mode (m=4) will be explained. When the 
scratch mode is designated by the user using the mode change-over switch, 
the register m is set to 4 in the foregoing mode SW event routine shown in 
FIG. 4. In the scratch mode start process MS(4), the waveform data to be 
scratch-reproduced is developed in the given region and the scratch region 
SR and the scratch pointer SP are set in advance. Although not shown in 
FIG. 6, when the operation of executing the DP routine per sampling clock 
Fs is stopped by the EX scratch mode or the like, MS(4) restarts its 
operation likewise the normal mode start process MS(0). 
In the scratch mode, the reproduction of the two tones caused by the pad-on 
is performed in a procedure essentially the same as that of the normal 
mode. The DP routine is executed per sampling clock Fs and all 0 samples 
in the reproducing buffer PB0, PB1 are repeatedly reproduced while the 
pad-on is not achieved, which are the same as in the normal mode, and a 
processing procedure upon pad-on is also the same. Further, the timing 
upon reproduction is also the same as in FIG. 17(a). However, in the 
scratch mode, the RC take-in routine RC(4) of FIG. 10 is executed by the 
timer interruption so as to take in the detection value of the ribbon 
controller 106. The note-on is written in the sound source register sch of 
the scratch channel at the start of the operation. Further, the velocity 
VEL of the ribbon controller 106 is detected and written in the sound 
source register sch. The waveform generation process of the CPU 101 is set 
to HS(4) of FIG. 12(a) instead of HS(0). In the waveform generating 
routine HS(4), the generation of the waveform samples for the two tones 
caused by the pad-on is performed by the normal 2 subroutine likewise the 
normal mode. Further, using the scratch subroutine (FIG. 14), the waveform 
sample in the scratch region SR is read out using the address SAD derived 
by adding the F number SFN to the address SAD. The read waveform sample is 
accumulated in the reproducing buffer PBr. By this, the scratch 
reproduction using the designated waveform data can be achieved in 
addition to the two tones caused by the pad-on. 
In the scratch mode, the number of tone generations is reduced from four of 
the normal mode to two. In place of the reduction in number of the 
generated musical tones, the scratch tones are generated. Since a given 
number of tone generations should be performed within a one-frame time, 
although four tones can be generated in the normal mode, a process time 
becomes insufficient when the scratch tones are additionally generated. In 
this regard, the number of tone generations is reduced to two so as to 
shorten a process time for the waveform generation, and the scratch tones 
are generated by using the remaining time. 
Next, the operation in the EX filter mode (m=5) will be explained. When the 
EX filter mode is designated by the user using the mode change-over 
switch, the register m is set to 5 in the foregoing mode SW event routine 
shown in FIG. 4. Although a flowchart of the EX filter mode start process 
MS(5) is omitted, MS(5) executes the starting process of the DR(5) 
routine. Specifically, the CPU 101 instructs the sound I/O 112 and the DMA 
controller 113 to interrupt the CPU 101 per sampling clock Fs fed from the 
Fs clock generator 110 and to execute the DR(5) routine of FIG. 15 upon 
every interruption so as to start the writing operation of the waveform 
samples from the external source into the recording buffer RBk. At this 
time, the operation of interrupting the CPU 101 per sampling clock Fs fed 
from the Fs clock generator 110 and of executing the DP routine of FIG. 16 
upon every interruption to reproduce the waveform data in the reproducing 
buffer is not stopped. If the operation of executing the DP routine per 
sampling clock Fs is stopped by the EX scratch mode or the like, MS(5) 
restarts its operation likewise the normal mode start process MS(0). 
Specifically, DP and DR(5) are executed per sampling clock Fs. In this 
case, since DP and DR(5) are operated following the same sampling clock 
Fs, they operate synchronously so that the interruption at step 1605 of 
the DP routine and the interruption at step 1505 of the DR(5) routine take 
place at the identical timing. Upon the interruptions caused at the same 
timing as a trigger, the waveform generating routine HS(5) of FIG. 12(b) 
is executed. In the EX filter mode, the external input signal is not 
recorded substantially. The external input signal is taken in the DR(5) 
routine, but this is for filtering the taken-in waveform data. Thus, the 
writing of the signal into the flash memory 103 is not performed. 
When the interruptions take place according to DP and DR(5) at the same 
timing as described above, 128 linear samples of the waveform data from 
the external source 111 are written in the recording buffer RBk while the 
reproducing buffer PBr is vacant. The waveform generating routine HS(5) 
performs the filtering process relative to the 128 waveform samples of the 
recording buffer RBk and sets the resultant 128 waveform samples in the 
reproducing buffer PBr. The RC take-in routine RC(5) of FIG. 9 is executed 
by the timer interruption so as to take in the detection value RD of the 
ribbon controller 106. The filter coefficient of the filtering process is 
determined depending on the detection value RD. In the foregoing fashion, 
the external input signal is filter-controlled by the ribbon controller 
106 so as to output a modified musical tone with desired timbre variation. 
Next, the operation in the EX scratch mode (m=6) will be explained. When 
the EX scratch mode is designated by the user using the mode change-over 
switch, the register m is set to 6 in the foregoing mode SW event routine 
shown in FIG. 4. Although a flowchart of the EX scratch mode start process 
MS(6) is omitted, MS(6) executes the following process. Specifically, the 
CPU 101 instructs the sound I/O 112 and the DMA controller 113 to 
interrupt the CPU 101 per sampling clock Fs fed from the Fs clock 
generator 110, and to execute the DP routine of FIG. 16 upon every 
interruption so as to stop the operation of reproducing the waveform 
samples in the reproducing buffer PBr. Further, the CPU instructs the 
sound I/O 112 to directly connect between the A/D input and the D/A output 
and to directly feed the musical tone signal from the external source 111 
to the sound system 114 so as to emit sound. Further, the CPU 101 
instructs the sound I/O 112 and the DMA controller 113 to interrupt the 
CPU 101 per sampling clock Fs from the Fs clock generator 110 and to 
execute the DR(6) routine of FIG. 15 upon every interruption so as to 
start the operation of writing the waveform sample from the external 
source into the recording buffer SRBk. In the EX scratch mode, the 
external input signal is not recorded substantially. The external input 
signal is taken by the DR(6) routine, but the taken-in waveform data is 
used for the scratch reproduction. Thus, the writing of the data into the 
flash memory 103 is not performed. Further, since the timer interruption 
is set effective during the initialization at step 301, the RC take-in 
routine RC(6) of FIG. 10 is executed per a given timing based on the timer 
interruption by the timer 105. 
While the ribbon controller 106 is not operated, the process is finished 
through steps 1001.fwdarw.1002.fwdarw.1003.fwdarw.END in RC(6) of FIG. 10 
so that the process of directly feeding the external input signal to the 
sound system 114 is continued. Further, since the DR(6) routine is 
executed based on the interruption per sampling clock Fs, the linear 
waveform samples obtained by A/D converting the external input signal are 
written into the recording buffers SRB0 and SRB1 alternately via the input 
FIFO. 
When the operation of the ribbon controller 106 is started such as the 
finger or the like is in touch with the ribbon controller 106, the routine 
proceeds through steps 1001.fwdarw.1002.fwdarw.1004.fwdarw.1005 in RC(6). 
At next step 1006, the CPU 101 instructs the DMA controller 113 to stop 
the execution of the DR(6) routine by interrupting the CPU 101 per 
sampling clock Fs and sets the scratch region SR in the recording buffer 
SRBk which is one of the two recording buffers SRB0 and SRB1 not currently 
subjected to the writing, as described with reference to FIG. 2(e). Next, 
the predetermined value of the scratch pointer SP is set as the initial 
reading address SAD at step 1007. Further, at step 1008, 128 samples to be 
reproduced first are generated for the reproducing buffer PBr, and the CPU 
instructs the DMA controller 113 to restart the execution of the DR 
routine by interrupting the CPU per sampling clock Fs. Further, the 
interruption of the same significance as the interruption caused at step 
1605 of the DP routine in FIG. 16 is generated. By this interruption, 
HS(6) is executed, and 128 samples to be scratched next are generated in 
PBr. Further, under the command from the CPU 101, the direct connection 
from the A/D input of the sound I/O 112 to the D/A output is cut so as to 
stop feeding of the musical tone signal directly from the external source 
111 to the sound system 114. 
Further, if the finger or the like moves while being in touch with the 
ribbon controller 106, the routine proceeds from step 1004 to step 1011 so 
that the velocity VEL is detected and set in the sound source register 
sch. On the other hand, in the DP routine which is executed based on the 
interruption per sampling clock Fs, the reproducing buffers PB0 and PB1 
are alternately accessed successively. Accordingly, the reproduction of 
the scratch tone is started based on the sound source register sch from 
the time point where the operation of the ribbon controller 106 is 
commenced. In particular, in the waveform generating routine HS(6) of FIG. 
12(c) which is triggered by the interruption at step 1605 of the DP 
routine, since RS=1 is held while the operation of the ribbon controller 
106 is performed, the routine proceeds from step 1221 to step 1222 so that 
the EX scratch process of FIG. 14 is executed. In the EX scratch process 
of FIG. 14, the waveform sample in the scratch region SR is read out using 
the address SAD derived by adding the F number SFN, which depends on the 
detected velocity VEL, to the address SAD and set in the reproducing 
buffer PBr. Although it appears that the accumulation of the read data is 
performed at step 1406, since all 0 samples are set in PBr, the waveform 
samples TMP to be scratched are substantially set in PBr. In the foregoing 
arrangement, the scratch reproduction using the waveform data inputted 
from the external source is achieved. 
FIGS. 18(a) and 18(b) show examples of conversion from the velocity VEL to 
the scratch F number SFN performed at step 1401 in FIG. 14. This 
conversion may be achieved through calculation or by means of a table. 
FIG. 18(a) shows an example wherein a variation of the F number SFN 
increases as an absolute value of the velocity VEL increases. This 
realizes the scratch effect such a manner that a pitch variation is 
significant even when the length of the ribbon controller 106 is small. 
Since the precise pitch control is not required in the reproduction of the 
scratch, the number of bits at a decimal portion of the scratch address 
SAD may be reduced if necessary. Specifically, the number of bits at a 
decimal portion of the address SAD derived at step 1403 in FIG. 14 may be 
reduced. This can reduce the calculation amount of interpolation performed 
at step 1405. Further, using a table shown in FIG. 18(b) upon conversion 
from the velocity VEL into the scratch F number SFN, the number of bits at 
the decimal portion of the F number SFN can be decreased to reduce the 
calculation amount of the interpolation. 
Further, in the foregoing EX scratch mode, the waveform data fed from the 
external source is stored alternately into the recording buffers SRB0 and 
SRB1, and the scratch region is set in the recording buffer which is not 
subjected to writing at the time of starting the operation of the ribbon 
controller. On the other hand, it may be arranged that no less than three 
recording buffers are provided in which the waveform data is stored in 
turn in a ring fashion, and the scratch regions are set in a plurality of 
the recording buffers which are not subjected to writing at the time of 
starting the operation of the ribbon controller. With this arrangement, 
since the scratch regions are set in the plurality of recording buffers, 
the scratch region capacity sufficient for the scratch can be ensured. 
Further, since the capacity of each of the recording buffers can be set 
small, the data amount on the recording buffers which are subjected to 
writing at the time of starting the operation of the ribbon controller is 
decreased. Thus, the data not used for the scratch can be reduced. Stated 
otherwise, discarded portion of the data can be saved. 
In FIG. 17(a), the head timings of the pad-on detection section, the 
section of the waveform generation by the CPU and the execution section of 
the DP routine of DMAC are shown to coincide with each other. However, 
this is not necessarily required, and the respective sections may be 
offset from each other. This also applies to the timings upon recording 
shown in FIG. 17(b). Further, in FIG. 17(a), the CPU performs the waveform 
generation at the time point where the reproduction of the samples in one 
of the reproducing buffers is finished in the DP routine. On the other 
hand, it may be arranged that the number of remaining samples not 
reproduced is detected in the reproducing buffer. When the detected number 
becomes no more than a given value, new samples are generated in vacant 
portions. Accordingly, by adjusting timings of reproduction and generation 
of samples, the number of the reproducing buffers may be one or no less 
than three. 
FIG. 19 shows an additional embodiment of the inventive musical tone 
generating apparatus. This embodiment has basically the same construction 
as the first embodiment shown in FIG. 1. The same components are denoted 
by the same references as those of the first embodiment to facilitate 
better understanding of the additional embodiment. The storage such as ROM 
102, RAM 104 and a hard disk (not shown) can store various data such as 
waveform data and various programs including the system control program or 
basic program, the waveform reading or generating program and other 
application programs. Normally, the ROM 102 provisionally stores these 
programs. However, if not, any program may be loaded into the apparatus. 
The loaded program is transferred to the RAM 104 to enable the CPU 101 to 
operate the inventive system of the musical tone generating apparatus. By 
such a manner, new or version-up programs can be readily installed in the 
system. For this purpose, a machine-readable media such as a CD-ROM 
(Compact Disc Read Only Memory) 151 is utilized to install the program. 
The CD-ROM 151 is set into a CD-ROM drive 152 to read out and download the 
program from the CD-ROM 151 into the RAM 104 through the bus 115. The 
machine-readable media may be composed of a magnetic disk or an optical 
disk other than the CD-ROM 151. 
A communication interface 153 is connected to an external server computer 
154 through a communication network 155 such as LAN (Local Area Network), 
public telephone network and INTERNET. If the internal storage does not 
reserve needed data or program, the communication interface 153 is 
activated to receive the data or program from the server computer 154. The 
CPU 101 transmits a request to the server computer 154 through the 
interface 153 and the network 155. In response to the request, the server 
computer 154 transmits the requested data or program to the apparatus. The 
transmitted data or program is stored in the storage to thereby complete 
the downloading. 
The inventive musical tone generating apparatus can be implemented by a 
personal computer which is installed with the needed data and programs. In 
such a case, the data and programs are provided to the user by means of 
the machine-readable media such as the CD-ROM 151 or a floppy disk. The 
machine-readable media contains instructions for causing the personal 
computer to perform the inventive musical tone generating method as 
described in conjunction with the previous embodiments. Otherwise, the 
personal computer may receive the data and programs through the 
communication network 155. 
As described above, according to the present invention, although the number 
of musical tones concurrently generated by the software sound source is 
reduced, the optional mode for performing the digital tone quality filter 
process, the pitch giving process or the scratch effect giving process is 
provided. Thus, the function which has not been achieved by the 
conventional software sound source can be realized so that the musical 
tone generation which meets various purposes of the user can be achieved. 
Further, according to the invention, in the tone generating apparatus for 
reading the digital waveform data to reproduce a corresponding musical 
tone, the detecting implement is provided to detect the touch action of 
the user. The waveform data is read out according to modified reading 
addresses which are determined depending on the detected touch action. By 
such a manner, the inventive digital music apparatus can create the 
natural scratch effect which has been obtained only by the conventional 
analog music apparatus, in response to the user's touch action. Further, 
the waveform data is read out from a predetermined top address when the 
touch action is initiated. Thus, the waveform data is always retrieved 
from the predetermined top address wherever the user touches the scratch 
detecting implement. Thus, the same repeat scratch operation is realized 
by the invention as performed using an analog record disk in which a 
particular section of the record disk is repeatedly reproduced in 
synchronization with a rhythm of the music. Moreover, the outputs from the 
detecting implement are differentially processed to detect a velocity of 
the touch action. Then, the variable F number is determined according to 
the touch action. The F number is accumulated to the reading address for 
use in reading of the waveform data. By such a manner, a variation range 
of the F number can be expanded with a limited length of the linear 
detecting implement, thereby realizing wide scratch control. Additionally, 
according to the invention, the scratch effect can be applied to a fresh 
waveform which is inputted from an external source in real time basis. 
Thus, the user can scratch a desired section of the reproduced musical 
tone during the live performance of the music.