NOR gate

The NOR gate is a redstone circuit added by RedLogic. It is a logic gate for complex redstone circuits. It emits a redstone signal if no signal reaches the gate (see Usage).

The circuit would be possible with Vanilla redstone mechanics, but this block reduces the size of the circuit to 1 block. This makes complex circuits clearer and easier to control. In electronics, this gate enables the physical execution of the boolean function "NOR" (negated OR).

Usage
The NOT gate has three input sides and one output side for redstone devices.

If no redstone signal reaches the input sides, then a redstone signal is emitted on the output side. If a signal reaches one of the input sides, then no signal is transmitted through the output side. Due to this property, the gate is called an inverter ("a signal causes no signal," respectively "no signal causes a signal").

Using the Screwdriver from RedLogic, the orientation of the gate can be changed freely in all four directions. Furthermore, using the screwdriver while crouching, the input sides can be turned off and on again in various combinations.