Re: Apple ][ music program (INTBASIC ?) with instrument pictures

[mjmahon@aol.com (Michael J. Mahon)]

Scott Alfter wrote:

>In article <48ac369b.0403240457.3b729a1e@posting.google.com>,
>Jason Armistead <Jason.Armistead@otis.com> wrote:
>
>>Rather than being a bunch of beeps and bops, the Apple ][ speaker made
>>synthesised violin-type (what I'd call "stringy") sounds.  I have seen
>>these same sound routines used for other programs and was hoping I
>>could dig up the source code or BLOAD-able code.
>
>There are a couple of programs out there for playing digital audio on 8-bit
>IIs.  SoftDAC, a program I wrote about 14 years ago, was one of the first. 
>These programs all work by turning the speaker on and off rapidly enough
>that the cone doesn't have time to fully move in and out.  While my goal
>when I wrote SoftDAC was to play what are now usually called WAV files, the
>same basic idea could be used for music synthesis, whether from wavetable
>samples or for waveforms generated in a more programmatic manner.
>
>I've not run across the program you describe, but the description sounds
>interesting.  I took a whack at music synthesis once or twice after doing
>SoftDAC, but never got very far with it.  It'd be interesting to see how
>this other program does what it does.
>
>(The core playback routine in SoftDAC is up for viewing at
>http://alfter.us/softdac.shtml.  The full program is available from
>http://alfter.us/files/softdac20b2.bxy.)

And it was Scott's _first_ SoftDAC (with only 3-bit resolution) that was
my first encounter with sampled sound on an 8-bit Apple II.  It inspired
me to write DAC522, a pulse-width-modulated software DAC that has
5-bit resolution and a 22kHz pulse rate--so the "carrier" is virtually
inaudible.

For any of you who think that 8-bit, unassisted Apple II sounds are
limited to "beeps", check it out.  The sound is so much better than
the internal speaker that headphones or an external speaker are
recommended for the full effect.

Almost ten years ago, Philip Lamb wrote a program "IISOUND",
based on my DAC522, which used a RAMWorks-style memory
card to extend the playing time.  And just last year, Simon ("Luddite")
wrote the TIMELORD rhythm machine using DAC522.  There were
a couple of games published on SoftDisks using the player for
game sounds, as well.

One of the things that a sample-based sound synthesizer permits
is very accurate pitches, which, I'm sure you've noticed, are not
the norm on 8-bit Apples, particularly in the higher registers.

There are lots of unexplored possibilities for sound on 8-bit
Apple II computers...  ;-)

-michael

Check out amazing quality sound for 8-bit Apples on my
Home page:  http://members.aol.com/MJMahon/