How do you remake 'Pong' without software?

In a post to r/gaming, Reddit user BluesImage has detailed how he recreated Pong using only logic chips and a circuit board. As the user explains, the original arcade version of Pong had no software or processor, instead relying on a network of chips to create the game. For his recreation, BluesImage re-worked the original schematics to fit with the parts he had access to as many of the chips were unavailable. After a lot of work, and a few hiccups, he was left with a fully-functional version of the arcade classic. You can see his recreation in motion below, and the steps he took to make it on Imgur.