This resistor, also known as Chua’s diode, can be created with an op-amp configured ... that the circuit is quite sensitive, so you might encounter issues when building it on a breadboard.

Truer words have rarely been spoken, because at the end of the day, every digital circuit is really just ... a nice entry in the recently concluded Op-Amp Challenge contest. His work began in ...

Before opening the Arduino software, wire up the Arduino according to the circuits page using the 8MHz minimalist breadboard circuit but with a 10k pull-up resistor on the reset pin (physical pin 1).