Re: issue with keyboard input for multiple keys Ctrl-b / nkey rollover?

[Yuri Khan]

On Sun, 2 Aug 2020 at 18:00, Alan Davis <alan3davis@gmail.com> wrote:
>
> I have left behind at least three different keyboards due to a problem
> when, especially backing up a character at a time, in Emacs, and perhaps in
> bash.  The following are the most recent keyboards with this problem:
>
>    - Microsoft Surface bluetooth keyboard
>    - A mechanical keyboard with Nkey rollover
>
> I quit using the first of these due to this problem, replacing it with the
> mechanical keyboard.  I hoped the Nkey rollover would mean key chords like
> Ctrl-b would work.

N-key rollover does not matter at all. Modifier keys (Ctrl, Alt, Shift
and whatever OS-specific fourth key you use) are always reported
independently in the USB HID keyboard protocol.

> Often
> when editing with emacs (truth be told I don't remember whether this is the
> case with a bash console), I have to repeat the keychord twice before the
> cursor will move.  So if I want to back up two characteris, I need to type
> Alt-b 4 times to move the cursor back 2 positions.

I suppose you meant Ctrl-b here.

> I am afraid I have not nailed down the specific instances when this
> occurs.   It has occured to me that this may happen with some terminal
> emulators but not on others. Even this seems to be inconsistent: in fact
> just now I tried this key combination in an emacs window, and it worked
> fine.

Stab in the dark: Do you use tmux some but not all of the time? It
uses Ctrl+b as prefix key by default, so you have to press it twice
for it to get reported to the application running within. You can
configure tmux to use a different prefix key.


Also, since you seem to be into mechanical keyboards, consider getting
one that puts arrow keys in an easily accessible place, or configure
layers to put arrow keys at your home row.