alt Hacker NewsBut if this doesn't satisfy your curiosity, you might realize this is just pushing the magic blackbox/question mark a little further down the chain
How does the OS and the hardware draw on the screen, actually? All they have is also just calculator stuff, super basic primitives. You can't even do loops in hardware, or even real branches (hardware always "executes both sides" of a branch at once)
Anyways, if you keep digging long enough you eventually end up finding this XKCD https://xkcd.com/435/ =)
> hardware always "executes both sides" of a branch at once
Unless you're talking about quantum hardware, that is very much not true. The whole point of transistors is to choose whether to power one part of a circuit or another.
Plus, even for hardware, the solution to all this is to modularize all the way down. One piece of hardware sets up the right state and powers up another piece of hardware - this type of logic doesn't stop at the OS level. For drawing on the screen, ultimately you reach a piece of hardware that lights up in one of three colors based on that state - but all the way there, it's the same kind of "function calls" (and even more indirection, such as communication protocols) on many levels.