Part 2: A Brief Introduction to termios: termios(3) and stty
Thanks for posting this! Somebody asked me about termios recently and we lamented, together, that conceptual overview of it is hard to find because it’s old, even though it’s still in use.
The chapter 18 of Stevens’s Advanced Programming in the UNIX® Environment is dedicated to Terminal I/O, or termios.
That chapter, followed by chapter 19 (on pseudo terminals), should give one a complete and detailed view on how terminals work on UNIX systems.
termio(7I) may be interesting to look at as well.