Re: Better sample of Crate.Synth music synthesizer

["Michael J. Mahon" <mjmahon@aol.com>]

Bill Garber wrote:
> "Michael J. Mahon" <mjmahon@aol.com> wrote in message
> 6MWdnVHtdappI97fRVn-vA@comcast.com">news:6MWdnVHtdappI97fRVn-vA@comcast.com...
>
> : Bill Garber wrote:
>
> : > One suggestion. Integrated the Nadanet with a IIgs instead of
> : > the IIe. Incorporate the extra ram in the IIgs and then get the
> : > Nadanet to play the entire piece in the IIgs ram. I know how
> : > much you like the IIe, but others might like to know that they
> : > can have 1, 4, or 8 MB of space to play music from.  :o)
> :
> : Bill, it's no fun making a synthesizer for the IIgs--it already
> : has a hardware synthesizer!  And lots of supporting software.
>
> Understandable, but I thought in 8-bit mode and using the
> extended memory of the IIgs you could do more. I see your
> point though.
>
> : The point is to do it entirely with software and on machine(s)
> : that "can't do that".  And, of course, to use parallel processing
> : to provide the multiple voices.
>
> Can we design a card to accomplish this, instead of putting the
> eight IIe boards together?? I'd like to do something like that,
> but I simply don't have the knowledge of sound frequencies that
> you have, by far.

A very close parallel to what I'm doing is the Mountan Music
System pair of cards.  They implemtented 16 digital oscillators
(wavetable oscillators), and, when used in pairs, could synthesize
timbre's that varied during a note (as used by Alpha Syntauri).

The Mockingboard and similar cards generate only squarewaves
with amplitude envelope control, so they are incapable of
different "instruments"--like a piano.

> : Making music with a IIgs is trivial--making music with //e's
> : and no add-on hardware is quite tricky.  ;-)
>
> That it is, and you've shown that it can be done. Great job, Btw.

Thanks!  I had a lot of fun making it work, and am having
a lot of fun making it work better and more generally.

> : BTW, it doesn't take much RAM.  The longest note track for
> : that nearly 3 minute piece is about 700 bytes.  Of course,
> : it takes 100% of a //e to produce one voice to 5-bit precision.
>
> Ah, I didn't think it was that small. I figured a few K to make
> a voice play a note. That is a lot of hardware though, don't you
> agree???

An "instrument" is about 4-8KB, but the music (notes and rests)
are only 3 bytes each, for durations up to 6 seconds.  The actual
synthesizer code is spread out over 4KB, with about 3KB of unused
space embedded in it (since the pulse generators have to be on
256-byte boundaries).  I've put a few tables into the "holes", but
it's still quite sparse.  So "instruments" are the primary consumer
of RAM.

The Crate machines run without any OS, and only NadaNet loaded
from $B800 to $BFFF, so everything from $800 to $B7FF is available
for use.  With SYNTH.CRATE loaded, space from $2900..B7FF is
available for instruments and music.  So far, that seems like
plenty--even for percussion "instruments".

With regard to using a whole //e to play a single voice--yes,
the machine is completely consumed, and you could regard that
as "a lot of hardware", but it is completely standard hardware
that every //e owner has already, and the going "price" for
//e's seems to be $5 to $10, which isn't "much" in the way of
hardware.  ;-)  Besides, there is no other way to produce
digitized sound on an _unassisted_ Apple II.

-michael

New Applesoft BASIC interface for NadaNet networking!
Home page:  http://members.aol.com/MJMahon/