Re: Trailing "m"s at the end of every line when viewing man pages
On Sun, 05 Apr 2015 11:59:49 -0400 (EDT), Paul E Condon wrote:
> Times change. If one waits even a short while, they can change a lot.
> When this terminal was new, a 'standard' terminal was a mechanical
> teletype manufactured by Teletype Corp. in Skokie, IL. The generic
> name for this 'terminal' was, I think, a 'glass teletype' Each
> computer company had its own special glass teletypes that interfaced
> to its computer. All proprietary.
> None of the glass teletypes had the very useful scroll back feature
> of the real teletype that they were trying to emulate. Teletype
> paper came in rolls. A single roll was a many meters long. It would
> pile up behind the teletype as one worked. It could always be pulled
> out and reviewed back to initial login at the beginning of the
> session. Some people left the paper behind for someone else to clear
> away. Others saved it, rolled up and labeled at their desks.
> It took 0.1 sec. to mechanically process one character, except for
> carriage return. That took up to 0.2 sec. The placement of the
> carriage return character before the non-printing line feed
> character allowed the carriage to get all the back to the left before
> a printing character arrived. It was in the design of teletype that
> this cr/lf feature was baked into our history.
Interesting history, thank you. The IBM 3151 is a "dumb" terminal in
the sense that it doesn't support scrolling backward. But my idea
of a "dumb" terminal is a line-mode terminal, such as a mechanical
teletype machine. The IBM 3151 is a full-screen terminal. You can
run ncurses-based applications on it. You can use full-screen editors,
such as vi. It supports high-intensity, underscore, blinking, and
reverse video, though it does not support color. It supports
clearing the screen. (It is a non-standard clear code, so the
standard code used by (a)getty does not clear the screen. But the "clear"
command works.) None of these things can be done on a line-mode (dumb)
terminal, such as a mechanical teletype machine. It is more than a
.''`. Stephen Powell <firstname.lastname@example.org>
: :' :