Joined Oct 2, 2009
The SN76477 Complex Sound Generator is an obsolete chip and you may have a difficult time sourcing it. I don't know what you mean by "work with a keyboard". The chip primarily uses a lot of RC inputs hence I doubt that it would be easily adapted to digital control.

I may be wrong about source, check ICS76477 at BG Micro:


Joined Apr 30, 2011
The data sheet shows a simple method using a separate resistor for each key but precise frequency control is not achieved by this method and it may not be valid for some keyboards since they don't incorporate simple NO momentary switches.

Mark Colan

Joined Feb 18, 2012
Search for SN-Voice. It is kind of an expanded SN76477 demo box that also features a 1v per octave interface, making it suitable for actual music (instead of just sounds). I'm building one, at least, once I manage to get all the parts. Some are a bit hard to find, but not impossible.