The central function of a computer is to perform operations on data. This is done with an Arithmetic/Logic Unit or ALU. This article presents an ALU that may be used to build a computer core around or used for other calculation needs. This shows the testing setup for the ALU: The layout of the ALU is modular: Only one result is enabled to the output bus, at any time. The vertical banks function as the multiplexer for the outputs. The opcode signal is the control to these banks and selects which output is enabled. This parallel arrangement allows for very fast operation. Details on the layout: