Design a Logic Probe that indicates the logic state of a node of any TTL circuit using two LEDs (a red one, and a green one). The probe must work with the same power of the circuit that you want to analyze: same Vcc and same GND.
Logic probe should be able to check the circuit using a "Test" wire connected to the desired node of the circuit that you want to test.
If the level is Low, the probe will display a "zero" (0) and only the green LED will be lighted. If the level is High, the probe will display a "one" (1) and only the red LED will be lit.