The indicated circuit uses an unusual buffer from National Semiconductor. The frequency is given by resistors R1 and R2 as well as capacitors C1 and C2.
We found this circuit in a William Sheets. The circuit is for frequencies up to about 500 kHz. |...
This shift register was found in old documentation. PUT is not a common component today. The...
In the figure we have the commercial circuit of a Japanese electronic voltmeter from the 60's. The...