Re: Gotta Learn Vi . . . . . . (was Re: [tlug] [Newbie] Becoming'root'in Kubuntu: Use sudo)

[Curt Sampson <cjs@example.com>]

On Mon, 27 Aug 2007, steven smith wrote:

> Curt Sampson wrote:
>
> > I don't think this is exactly the point. First of all, the original
> > vi was developed on and for 9600 bps text terminals, and second, even
> > modern vi works on a 300 bps link.
> It sounds like it was a pretty big deal at the time:

Ah, that's the optimizing screen updating code, what became curses, as
it turned out in the end. Even 9600 bps terminals benefit dramatically
from that. (Basically, the programmer just tweaks a character matrix,
and curses figures out the optimal set of cursor moves to do the screen
update.)

That's great stuff, but it's not at all vi-specific. it would work just
fine for Emacs, too.

Come to think of it, though, vi did have a few features that avoided
doing screen updates to help keep the speed up, such as having 'C'
(change to end of line) leave the current data on the screen, which
you would overwrite, and only cleaning it up after you'd finished the
update. This saved sending all the spaces to clear to the end of the
line and then moving back to the insert point.

cjs
--
Curt Sampson       <cjs@example.com>        +81 90 7737 2974
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