[sdiy] How does a DCO work?

[Samppa Tolvanen]

Hi,

I can only tell about Roland stuff, but I guess that other Synth
manufacturers used the same principle (?!?)

DCO -> HF clock divided down to audio frequency by a programmable counter.

Most Rolands used 8253 for that: Three programmable 16 bit counters in
single chip. I hope I don't upset anyone by saying that it seems like
one of the most "Synth friendly" chips ever ;)

See http://fa.utfs.org/diy/jx3p/jx3p_schem.htm for JX-3p schematics as
a reference and
http://www.intersil.com/products/deviceinfo.asp?pn=82C54 for datasheet
of "just a bit" updated version of that chip.

Bye, Samppa