Analogue Computer knowhow?

[Grant Richter]

> This leads me to wonder whether perhaps when we make the standard modules
> we are working at too high a level.... perhaps we should make much
smaller
> more elemental units such as integrators, comparators, adders,
multipliers
> and so on..... this would surely have the effect of making modular synth
> music more interesting? this approach has not been viable in the past
> because of 

Thats a good idea - not only that but the only chip you would need would be
the mighty LM3900. If you look at the 3900 data sheet this chip can be used
for more sub-functions than anything else I've seen.

Just fer Gee Whiz instance - because both inputs are current summing
junctions you can implement Minsky-McCulloch "neurons" as logic gates.
Example: Assume a logic level of 10 volts. Take two 100K resistors into the
positive input. Now have two 75K resistors into the negative input. If only
one of the negative inputs is high the threshold is "1" and the output goes
high if either input goes high. A logical OR gate. If both negative inputs
are high, then the threshold is "2" and the output will go high only if
both positive inputs are high. A logical AND gate. Using a single resistor
into the negative input and varying the voltage you can dynamically switch
the logic function of the gate. Pretty cool and real cheap too. For more
info, look under "Marvin Minsky and/or Warren McCulloch" at a University
library.