>>31
Why do you think things are so different?
If you really want to learn how *insert popular CPU* works (like x86), get yourself a lot of money and reverse engineer it in a FA lab, or buy papers from chipworks. Modern CPUs aren't that different from older ones, they just use more complex processes, are more optimized, sometimes even full-custom. If you want to learn the workings of other components (RAM, buses, interface cards, and so on, you can choose to read the standards so you can see what is expected of each component (the interface), and from there you can figure out how to implement such components or see if there's any open source implementations for you to look at). It's really no big secret, most of the info is out there publicly for you to read and understand, and if you want hands-on experience, you can get it.