[sdiy] Polyphonic keyboard scanner

[Ingo Debus]

Am 31.07.2009 um 18:52 schrieb David G. Dixon:

>  Does anyone here know of a polyphonic keyboard scanner
> circuit based on logic IC's (non-programmable)?

There was one in ETI (Elrad in Germany). Tony of Oakley Sound  
mentioned it very recently. Yes, it was a massive pile of chips.

Wanting to build a polyphonic synth was what got me into  
microprocessors back then.

Ingo