This TTL heads or tails circuit was found in the July 1973 Radio Electronics magazine. The LEDs are types of the time. Note the symbolic representation of this component.
MCP19124/5 Contains Independent Voltage and Current Control Loops Plus a Full Suite of...
This circuit is designed to control static loads fed by direct voltage. The circuit is from...
This circuit is from an American 1964 documentation. Transistors of the time are used, but modern...