This circuit was found in an Elektor from the 90s. Transistors are common and status indications are made through LEDs.
In the figure we have the way to use the 555 to control loads in the bistable form. The circuit is...
This continuity test was found in a 90s Electronic Engineering. Transistors are types of general...
Suggested by a 1968 Philips documentation this Eccles Jordan rocker as it was called can operate...