[sdiy] Goofy matrix switch idea

[Grant Richter]

I have always wanted to use a CD22100 4 x 4 crosspoint switch in a synth.
They contain 16 switches in a 4 x 4 matrix. Obsolete now, but you can find
them in the surplus pipeline. They were $0.95 when still in production and
handle +/- 5 volt signals.

The problem is they are programmed with a pulse train to set the switches on
or off. It normally needs a 16 bit shift register or microprocessor to
control them.

Anyway, I realized the patterns from a CD4089 rate multiplier chip MAYBE
could be used to program the switches. Mostly turn them all on with only two
on at the smallest setting. Or invert the logic and turn them mostly off, or
gate the pulse train???

Very cheap and might be a patch matrix for a circuit bent thingie or
electronium.