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harmonics.readme
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2004-09-23
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Short: Create sounds by adding together sine waves
Author: kimflarsen@hotmail.com (Kim Fastrup Larsen)
Uploader: kimflarsen@hotmail.com (Kim Fastrup Larsen)
Type: mus/edit
1 LEGAL STUFF
Harmonics version 1--a simple additive synthesizer
Copyright (C) 2004 Kim Fastrup Larsen
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later
version.
This program is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied
warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the GNU General Public License for more
details.
You should have received a copy of the GNU General Public
License along with this program; if not, write to the
Free Software Foundation, Inc.
59 Temple Place - Suite 330
Boston
MA 02111-1307
USA
2 WHAT DOES IT DO?
Harmonics is a simple waveform synthesizer program.
Waveforms a created by adding sine waves of different
frequencies and amplitudes. You are limited to working with
12 different frequencies: The base frequency (called the
first harmonic), base * 2 (the second harmonic), base * 3
(the third harmonic), and so on up to base * 12 (the twelfth
harmonic).
Harmonics are added to the waveform simply by adjusting the
twelve sliders that determine the amplitude of each harmonic.
Setting a slider to zero (far left) leaves that harmonic out
of the waveform altogether. The resulting waveform is
automatically scaled to use the full amplitude range of -127
to 127.
You can test the waveform by playing notes with the keyboard.
You have two full octaves available on the keyboard at any
time. You can choose between the 5 available octaves using
F1-F4. Yes, that's only 4 keys, but since you have two
octaves available at a time, this WILL give you access to all
5 possible octaves. Try it out, you'll see.
Harmonics projects contain simply the setting of the twelve
sliders and so are very small files. In order to use a
waveform in another program you must use the "export IFF"
facility of the program. This will save a 5-octave IFF 8SVX
sound file that most Amiga music software will be able to
load.
Full sources are included for your amusement.
3 A NOTE ON SOUND QUALITY
Harmonics generates 5 octaves of waveform data. The lowest
octave is a 256 sample waveform. The higher octaves contain
128, 64, 32 and 16 samples, respectively. This ensures the
highest sound quality possible on an Amiga. Still, you
should observe the following limitations:
Harmonics 9-12 will be inaudible or distorted in the two
highest octaves. Harmonics 5-8 will be inaudible or
distorted in the highest octave. Harmonics 1-4 sound fine in
all octaves.
Therefore, if you wish to make use of all 5 octaves, you
should only use harmonics 1-4, and likewise if you want to
use all but the highest octave, use only harmonics 1-8. If
you need only the lower 3 octaves, you can use all harmonics.
Also note that if you somehow switch off the Amiga's built-in
low-pass filter you WILL experience distortion (so-called
"aliasing distortion"--the sampling rate interfering with the
sound frequencies) that would not otherwise be noticable.
This is due to hardware constraints and cannot be avoided.
The filter is there for that very reason. Some music
software switch off the filter without asking or even
informing you. You can tell that the audio filter is
switched off if the power led is dimmed.
4 WHAT'S UP WITH THE ANTIQUATED STYLE?
I programmed this in Kickstart 1.3 style. It should run on
every Amiga ever sold by Commodore. Why did I do it like
this? For the fun of it, I guess. I like the simplicity and
flexibility of the old Kickstart. The playful philosophy of
the Amiga went out the the Windows (sic) with 2.0. Display
database? What a nightmare. Don't try to be something
you're not! Amiga 500 rules, etc.
Consider it a design exercise. I tried to make it as simple
to use and easy to understand as possible for the computer
novice in the true Amiga spirit. Consequently, the program
does not even have "proper" file requesters. This shields
the user from files not seen on the Workbench. The user can
load projects by multi-selecting icons or using the "default
tool" mechanism so entering filenames is kept to a minimum
anyway.
I also tried to make the software "safe" and "professional"
with a full complement of menus, requesters and error
messages. There are no bugs or design problems that I am
aware of. But please report them if you find any! See below
how to contact me.
The look of the program is totally borrowed from Workbench
1.3 and requesters look a lot like Kickstart 1.3's system
requesters. I am a programmer, not a graphics designer.
Anyway, it looks nice if you ask me. Who needs Gadtools? It
does look best when run under Kickstart 1.3 though.
Harmonics was actually coded on my beloved A4000/030 so go
figure. It has been tested under various A500-like
conditions as well using WinUAE.
5 CONTACT ME
If you have bug reports or other comments, you can reach me
(Kim Fastrup Larsen) on the following e-mail address:
kimflarsen@hotmail.com
6 HAVE FUN!
Have fun!