One of the more famous of these devices is the 74181, a cascadable 4-bit arithmetic logic unit, or ALU ... look at this 4-bit 74 logic single board computer.

When thinking of retrocomputing, many of us will imagine machines such as the Commodore 64 or Apple II. These computers were very popular and have plenty of parts and documentation available.

There are different types of memory – volatile and non-volatile. The Arithmetic and Logic Unit (ALU) is where the CPU performs the arithmetic and logic operations. Data is passed to the ALU to ...