Belgian Amiga Club - ADF Collection/BS1 part 60.zip/BS1 part 60/Multimedia FX.adf/MFXDOC/MFXD35

Text File | 1992-07-24 | 8KB | 240 lines

EDIT CONTROLS
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The operator controls are grouped into
two categories: OSCILLATOR and SOUND
TRIGGER.
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The OSCILLATOR controls are used to set
the wave shape, frequency, and
interaction with other oscillators. They
also determine how the waveform is
applied to the selection of pictures.
The SOUND TRIGGER controls determine
how the waveform is used to trigger
sounds. Both types consist of faders and
switches.
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Because the screen display is in a 16
color mode (necessary to prevent DMA
from stealing processor time when CHIP
RAM is used), the
panel controls share the same palette
that the animation uses. As a result,
depending on how the palette is set, the
panel controls may be difficult to read
(especially the switches). To avoid
this, set the palette for ease of use
while you are editing. Set the palette
for final viewing when editing is
completed. The Help key forces a
grey scale palette if you get lost.
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When editing, the sound triggering can
be disrupted ... resulting in gaps or
glitches in the sound output. After a
moment, things settle back down. The
settle time will depend on the operator
settings.
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Although there are four volume controls
(one for each operator), it's a good
idea to make use of the volume control
on your T.V. or stereo when you are
editing ...
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OSCILLATOR CONTROLS:
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* Directly below the image display window,
there are 12 vertical fader controls.
They are labeled FREQ, G, B, AM, and FM.
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FREQ - There are two faders for
frequency; one is coarse and the other
is fine. The upper half of the range is
the same as the lower half reversed.
These two controls set the base
frequency of the oscillator.
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G and B - The two faders marked G and B
control the gain and bias of the output
of the oscillator to the picture
selection. The gain control sets the
peak to peak level of the output. The
bias control allows the output to be
offset. Both of these controls determine
how the oscillator wave will be applied
to the selection of the picture that
will be displayed. Observe the "sum"
display indicator to see their effect.
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AM - Each of the four AM inputs modulate
the gain of the oscillator. Each comes
from one of the four oscillators
(including itself).
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FM - Each of the four FM inputs modulate
the frequency of the oscillator. Each
comes from one of the four oscillators
(including itself).
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Along the bottom of the screen is a long
horizontal fader with a button at each
end. This controls the symmetry of the
wave. Moving the fader to the extreme
left produces a ramp wave. A center
position produces a symmetrical wave.
The right side lengthens the second half
of the wave cycle causing the frequency
to decrease. The buttons on each end
control whether the wave is linear or
sine. The one on the left controls the
first half of the wave cycle. The one on
the right controls the second half of the
wave cycle. For example, if the fader is
in the center and both buttons are on,
the resulting wave will be a sine wave.
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Directly below the EDIT button are 4
buttons which allow the oscillator to
"hard sync" the other oscillators. This
allows synchronization between
oscillators.
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Directly below the COPY button (for
preset copying) are four buttons which
affect the oscillator. When the top one
(which shows a right pointing arrow with
bump on its point [ inversion symbol ] )
is on, the waveform is inverted (the
gain control fader is reversed as well).
Below the inversion button are two
buttons with a stair step (square wave).
One has a small M next to it. These two
buttons turn the waveform into a square
wave. The one without the M turns the
wave "Square" as it is applied to the
picture selection (sum). The one with
the M turns the wave "Square" as it is
applied to the other oscillators for AM
and FM modulation. Below these two
square wave

buttons, is a button with
four arrows pointing inward. This button
has a different effect, depending on
which oscillator it is with. For
oscillator #1, it is a 'slew' control.
It has a global effect. When selected,
the summed wave that is selecting
pictures is prevented from skipping
frames and instead is slewed. It affects
all waves that are being summed. When
this button is selected while editing
oscillators 2, 3, or 4, its respective
oscillator is turned off.
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SOUND TRIGGER CONTROLS:
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The sound trigger controls fall into two
categories. One that selects the method
of triggering, and one that specifies
how the sound is to be played once it
has been triggered. In the upper left
section are a group of 7 vertical
faders. Below these faders are five
buttons. These controls affect the
trigger method.
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The group of four marked TRIG.F use
frequency information to cause a sound
to be triggered. Going left to right,
the first two specify the target
frequency (like the frequency of the
oscillator is specified ... coarse
fine). The third specifies the capture
range (same scale as the coarse
frequency control). The fourth specifies
how long the actual frequency must be in
the capture range before a sound will be
triggered.
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The group of three faders marked TRIG.A,
use amplitude information to cause a
sound to be triggered. Going left to
right, the first specifies the amplitude
level required to trigger a sound, the
second specifies the capture range, and
the third the amount of time the
amplitude level of the actual oscillator
must be in the capture range before a
sound will be triggered. Below these
three faders are two buttons marked +
and -.  The + sets it so that first have
of the wave is examined for amplitude
information. The - button does the same
for the second half of the wave cycle.
Both may be on for positive going and
negative going triggers. If both are
off, no sound can be triggered.
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The group of three faders marked TRIG.A
have a dual function: if the first
fader, going left to right is raised all
the way to the top, another mode is
selected for amplitude triggering. The
second fader specifies the amplitude
level for triggering. The third
specifies a harmonic frequency of the
oscillator frequency that will be used
instead of the oscillators frequency.
The + and - buttons are in affect as
well.
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The button to the left of the + button
(shows a rectangular pulse) is used to
allow retriggering, even if the trigger
cause is still satisfied.
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The button below the - button (shows
three steps) is used to enable the note
quantizing function. When this button is
on, any triggered sound will be
quantized (playback sample rate) to the
nearest semitone.
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The button to the left of the quantizing
button is used to affect which Amiga
sound channel (there are four) will be
used to play any triggered sounds. If
the button is off, the sound will always
be triggered on the same channel
(corresponding to the operator number).
If the button is on, each subsequent
triggering will go to the next available
channel on a round robin basis. The
other operators must also have this
switch on if they are to be made
available for use as an available
channel.
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Once a sound has been triggered, there are
four groups of faders which affect what
part of the sample will be played,
how loud it is, and what the playback
sample rate is. The four groups are
marked START, LENGTH, RATE, and GAIN.
Each group has five faders, four being
sources from the four operator waves,
and the fifth is the base position of
the index. The four waves are summed and
then added to the fifth to produce a
total value. START specifies where in
the 65K sample the beginning of the
sample will be. The LENGTH specifies how
long the sample sound is to be. RATE
specifies the playback sample rate. GAIN
specifies how loud the sound will be.
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