This interesting circuit of an Electronic Design stores the highest voltage of two applied to its inputs. The circuit is from 1964 and can be adapted to use modern components.
This fast trigger circuit allows the counting of up to 300 pulses per minute. The circuit is from...
This intercom uses transistors from the 60s. It was found in a Japanese publication at the time....
This circuit is from an old publication from the 90s, but it can be adapted to operate with LEDs....