I found a site this morning called nandgame (http://nandgame.com/)

Nandgame is for learning how computers physically work down to the lowest level you can get to before it is electrical engineering rather than computer-related science. It is a puzzle about how computers use normal electrical circuits to actually do what they can do for us every day. If something like this was implemented into khan academy in the same way the coding challenges were, along with some videos, it would be one of the best ways to learn about computers on the internet! I really hope the khanacademy team is reading this and taking this into consideration. Thanks for reading.