Operating Systems: Three Easy Pieces by Remzi H. Arpaci-Dusseau & Andrea C. Arpaci-Dusseau (University of Wisconsin-Madison) is an excellent book and used by many universities worldwide. Extremely well written and it’s one of the only textbooks I’ve ever completed from start to end.
It’s also completely free: https://pages.cs.wisc.edu/~remzi/OSTEP/
Isn’t Angstrom 10^-10 meters? And nanometers 10^-9 meters? So 20A (assuming A = Angstrom) is just 2nm?
Are they trying to say that by moving to this new era, they’ll go single digit Angstrom i.e., 0.x nm?