This TTL shield with high level logic is from the LM111's own 80's manual. The integrated circuit is no longer easily found, but the circuit can be adapted to use modern equivalent operational amplifiers.
In the figure we have the simple way to obtain a digital inverter using a general-purpose...
This circuit works with only 1.5 V and can be powered by a solar panel. The circuit is from 1991....
This circuit was found in a 1969 EEE. The circuit uses transistors from the era that can be...