Two weeks ago we successfully ran(crawled) Doom on a CPU we built from scratch. To be honest, I still can't believe it. What did we really do though? Well, we designed a custom CPU at the logic gate level, connected it to peripherals, adapted the DOOM source code to run on our machine, and deployed it onto an FPGA to run in real time. Before running Doom, we had only run simple programs that we had written, like Pong and Mandelbrot sets. Now we can run full published games, but getting here was...