The circuit shown is from National Semiconductor's Linear Applications Handbook. It makes use of the LM78S40 which is not an easy component to obtain today.
Here we show an oscillator that uses an LC network. The upper limit depends on the power-supply...
This circuit from a Popular Electronics from the 90s allows you to use an old PC as a digital...
of the National Semiconductor of 1994. The same technique can be used with other operators and the...