The Comparator
The comparator can be used to measure the fullness of a block. When used with inventories, the strength of its output will be proportional to the fullness of the inventory.
This also applies to many other blocks that are not inventories.
When measuring an inventory in this way, it can have a solid block between it and the inventory.
It can also be used to manipulate the strength of a redstone signal. It can do this with two inputs. The primary input is from the back, and the secondary input is from the sides. (If there are two signals coming in from the sides, then the strongest signal will be used.)
It has two modes. In the default mode, it will output the primary signal only if it is stronger than the secondary signal. Otherwise, it will output no signal.
The second mode is subtraction mode, which is switched by clicking on the comparator. This will enable the redstone torch.
In this mode, the strength output is the strength of the back signal minus the strength of the side signal. If the back signal is not stronger than the side signal, then no signal will be output.
Workbench.name
Redstone Comparator
