Here it is May 26, 2019 and want to present a brief video history of Light Logic and a working full adder using Nand DRL gates.

The basic Nand full adder circuit used for this project.

Laying out the gates.

Wiring the first XOR.

Wiring the entire adder. My wiring was very messy on this project.

First test was setting A In to one. Note the glow of the gates as they are active or inactive. Sum Out indicates a one.

Now A In and B In are set to one. Sum is zero and Carry Out is one.

A In, B In and Carry In are one and Sum along with Carry Out are one.

This is a great educational tool to visually see the actions of the gates while functioning.