Ctrl-C stops the program because the TTY driver watches for it and sends an interrupt signal when it appears. It's a slightly different mechanism.

There are more details in "man 3 termios", but be warned, the TTY layer is not a pleasant subject for reading.

I was disappointed that Ctrl-S and Ctrl-Q don't correspond (at least on the first ASCII chart I googled) to anything, because Ctrl-S stops text on my Unix terminals the exact same way it did on my brother's Apple ][e in 1984.

> I was disappointed that Ctrl-S and Ctrl-Q don't correspond (at least on the first ASCII chart I googled) to anything

I'm pretty sure every possible combination of 7-bits is assigned SOME name in ascii, and Ctrl-any-case-insensitive-letter is a defined 7bit value.

This chart says control-s is `DC3 (Device Control, X-OFF)` and control-q is `DC1 (Device Control, X-ON)`. Yup, that's what they do alright.

http://www.unix-manuals.com/refs/misc/ascii-table.html

Don't forget everyone's favorite control-G, BEL, useful sending beeps across the wire on old school IRC, BBSen, and chat services. Or, you know, telegraph machines or something.

For anyone wondering, X-ON and X-OFF are flow control characters. A device sends X-OFF to say "my buffer is full, stop sending data" and X-ON when it's ready to resume.

On most Unix terminals, these have the effect of pausing and resuming the display when a bunch of data is scrolling by.

...and they're helpfully disabled with stty -ixon

Oh, thank you. The reference I found[1] only showed them as "device control." I thought I imagined them having that.

Also, the classic control-G is still in C. "\a" is "alert (beep)."

[1] http://www.asciitable.com/

I think you mean your brother's Apple //e - they switched from the original ][ to // for later models. That's what I started programming on too - except in my case it was my Dad's.

Ah, but the boot screen said "APPLE ]["

Ctrl-C was originally "End of Text".