Im studying CS right now (community college) and we have two low level courses. In the first one we use Nand2Tetris and also build a SAP-1 (simple as possible) computer following Ben Eaters YouTube series. One of the coolest classes I've ever taken. We all built an actual working computer on a fricken breadboard.

The second class is the one im taking right now on x86 assembly and its cool but definetly not as fun as building a computer from scratch.

If no ones has watched Ben Eaters videos I highly recommend them.