Tue May 30 18:46:36 CEST 2017

Demo? MIDI + sequencing

Sequencing is actually more interesting, so lets do that first.
Assuming synth.fm is where to start..

Mainloop runs:

Likely this got a little out of sync.  Am I going to overwrite the
code?  Probably should.

Yes that was not a problem.

Now, why does midi not work?
Is output actually going to the midi out?

Was connected backwards.  Easy to test with scope: pin6 of opto has
3v3 serial out.

Next: make some sounds selectable.  Fix the generators?

It seems that both note on/off and cc work.  What to do with it?

: play-last
    notes-last #xFF = if silence ; then
    notes-last midi-note
    _dup period 2!

Instead of silence and _p0, this should call user-defined functions.
So step 1 is to vectorize these.

Incremental development: 
- make words that take a 2-byte period to select different generators.

First: _pwm works
Maybe it is because of stack underflows that it sometimes hangs?
Restarting the interpreter seems to work.

So it shouldn't be that hard now.  Only thing left is the encoding.
Maybe put this in a separate file?