Nand only! Yep. Only nand. Output and inputs are not affected. Original instructions: This is a simple simulator of Computer Logic. You can build logic circuits and play with them. There is an edit (yellow) mode and the normal mode (blue). Use the elements at the bottom and build functioning logic circuits. you need to use inputs to trigger the function of the gates. the squares of inputs, outputs and gates are connectors and must overlap to make a connection. wires are one-way from the first click to the second klick. You can branch to another gate at any point on the wire except both ends.