nrh (07/30/82)
The main reason for not just adding stuff to the tty driver because it "is an obvious enhancement", or it "would be useful" is that the tty interface should be as simple, as clean, and as useful as possible. The nice thing about keeping that stuff simple is that your code remains transportable, and the tty code does not tend to bristle with features added for special programs. Harvard had at one time 3 special-program tty modes -- TECO mode, PPL mode, and DDT mode. As I recall, they could have used either the modern CBREAK mode (it didn't exist then), or a "these chars are break chars" mode. My own suggestion (untried) is that there should be a way to specify which characters are "break" characters, and which characters are "signal" characters (very raw mode). Given this, you only have the problem of ^S/^Q, ^O, and the other goodies from tenex.... Didn't someone propose "mounting" tty code on "raw" ttys? How did that work out?