This simple logic test circuit with 3 LEDs was found in October 1985 Radio Electronics magazine. The power supply is according to the logic, and this version is indicated for TTL.
This circuit is from a Radio Electronics magazine from August 1974. It used one of the first...
This circuit was found in an English magazine from 1973. The magazine no longer exists, but the...
This circuit for measuring very low currents was found in an American documentation from the...