MM-977 Quad Boolean Logic module is made up of 4 identical 'sub modules', allowing you to process up to 4 pairs of cv signals using Boolean Logic to output 4 'gate' signals (either LOW (0.0v) or HIGH (5.0v).

Each input is turned into a binary value (LOW or HIGH) based on a threshold of 2.0v, anything below is LOW, anything above is HIGH. From there, the two signals are processed based on the operator selected by the control knob:

AND: outputs HIGH only if both of the inputs are HIGH

OR: outputs HIGH if either or both of the inputs are HIGH.

XOR: outputs HIGH only if one input is HIGH.

The INV switch then inverses this if active - HIGH becomes LOW, LOW becomes HIGH. This is how you can utilise NAND, NOR and XNOR operations.

For extra added fun, try chaining these together!