Re: [groff] 04/05: {g, n}roff.1.man: Give assistance to pager users.

[Tadziu Hoffmann]

> > Some terminals, the Tek 401x series especially, could
> > be configured to tell the host to stop sending text on
> > a "page full" condition.  Some sent the proper RS-232
> > hardware signals, some sent <ctrl-s>/<ctrl-x>.

> Really? That's interesting. What did <ctrl-s> do? On the
> terminal emulators I have on hand at the moment, none of them
> are responding or behaving differently.

I remember these as <ctrl-s> and <ctrl-q> (ASCII DC1 and DC3).

Typing "stty -a" gives (among other stuff):

  start = ^Q; stop = ^S

and it works as intended (<ctrl-s> stops output to the terminal
and <ctrl-q> enables it again).

Wikipedia has a page on this:

  https://en.wikipedia.org/wiki/Software_flow_control

Particularly irritating was emacs's use of <ctrl-s> for
"search" because it conflicted with this flow-control, meaning
that you had to either reconfigure your tty settings or the
emacs keybindings.  (Vi did not use <ctrl-s> or <ctrl-q>
and was therefore "safe".)