Integrator with JFET (CB6229E)

This circuit was found in an 80s National Semiconductor documentation. The configuration holds true for modern JFETs.

Musical Bell (CB16731E)
We found this circuit in a 1992 documentation. When the button is pressed, the circuit produces a...
Synchronized astable (CB21832E)
This circuit was taken from the 1974 Ferranti transistor manual. Note the shapes of the signals....
IGFET Dip Meter (CB5173E)
This circuit was found in an American 1980s documentation. It makes use of an unusual MOSFET today...