I'd want to know about interactivity between hardware and software.
I would want to know about how you can for example draw pixel in the screen and how you can for example send software information about mouse movement. When I use engines to do that, such as Pygame, there are in the end many things hidden behind the scenes. I've tried exploring files of Pygame package, but pygame.__init__ is rather just importing modules, which are almost unreadable. With Pygame documentations I've understood, that Pygame is much based in SDL library. How does SDL library then handle the input and output data? I'd want to know about some ways to make software interact with hardware, ways, where not much things are hidden behind the scenes. I am not much interested in Arduino, Raspberry π or similar, I'm rather interested in develoπng my own, low-level engines.