Now that we’re approaching the end of the course you might be eager to see the whole thing in action. There is no better way to learn anything that when you’re facing the task of building a working system. And I mean to build all of it!
Most of the time you work on a personal computer. Not the hardware or the operating system are part of what you have to build. In an extreme case you might be rebuilding the kernel of the operating system you’re running.
If you like hardware and to experiment I propose you to get one Arduino board and a LAN adapter for it. I’ve used in the past the ones I’m referencing and I’ve found that seller the cheapest option at the time.
Arduino is an easy-to-use low-cost “open hardware” microcontroller board around ATmega168 chip. USB bus server to both power the board and download developed code to it. Many extensions are possible and the LAN card adds a simple Microchip LAN controller to Arduino. All the source code you see is all what’s available: no operating system below, no hidden strings, just the bare source of the library.