[hpsdr] Somewhat OT: howto prog a soundcard

[David Woods]

This is likely off topic for this list but maybe others could benefit
from any replies.

I am interested in learning how to program a sound card (or maybe
eventually janus/ozy) to generate a simple sine wave tone at first,
eventually leading to knowing how to do other waveforms,
multifrequency (DTMF), and other things.  Certainly there must have
been written a beginners howto guide on doing this -- but Google has
not given me any good leads.

A pointer to one or more web tutorials would be preferred,
alternatively books or other sources are OK.  Keep in mind, I'm
looking for something for a novice in this.  I do have the DSP book by
Smith and other resources, but they do not seem to convey some hands
on experience in doing this.  There's a lot of nice tone test
generators available freeware, but most I've seen are not open source
so I cannot see how they did it.

Thanks for any information you might supply.

David