[erlang-questions] help: Erlang MIDI driver for MAC OS X

[Bob Ippolito]

On Jan 21, 2008 6:29 AM, Joe Armstrong <erlang@REDACTED> wrote:
> Thanks - I'd discovered this :-)
>
> I have actually made great progress after about 9 hours of searching
> and messing around suddenly things
> bust into life.
>
> I have now made a primitive OS-X midi driver - so now I can both send
> and receive real-time midi events
> and make horrible noises.
>
> The interesting thing is that this really does bring home to me how
> appallingly difficult it is to write even simple
> code today.

Well, the reason Apple's CoreAudio APIs look like that are because
they're designed to have *very* precise timing, where you wouldn't be
able to do that properly over a file-like device. The APIs are a pain
in the ass and it sucks when you don't need that but that's why it's
designed that way. I think that the CoreAudio stuff lives in the
real-time parts of the kernel so when you get a callback it's at a
very high priority and you're not even supposed to allocate memory or
anything that might interrupt.

-bob