[sdiy] Protecting microcontroller inputs from - voltage?

[john mahoney]

> Question #2: What's the easiest way to clip out negative voltages?

Check the Thomas Henry link posted by Michael Bacich:
http://www.midwest-analog.com/diylvco.html (thanks, Mike).
Tom wrote that "... the VCO should be protected in case someone clumsily
attempts to patch in a negative CV."  His circuit supposedly has such
protection. Maybe somebody else here can explain what it is.
--
john