xmodmap 1.0.7: "left shift" + "right shift" + "comma" keys

[YuGiOhJCJ Mailing-List]

On Thu, 13 Mar 2014 16:56:17 +0000
Glynn Clements <glynn at gclements.plus.com> wrote:

> 
> YuGiOhJCJ Mailing-List wrote:
> 
> > What is a bit strange is that my keyboard can handle the "left
> > shift" + "right shift" + "exclam" but is not able to handle the
> > "left shift" + "right shift" + "comma" that seems to be similar
> > (same number of keys pushed at the same time).
> 
> I did a quick test. This is with a UK keyboard; the bottom row is:
> 
> 	[Shift] \ Z X C V B N M , . / [Shift]
> 
> 
> With the left and right Shift keys held down, the keys
> 
> 	\ B N /
> 
> generate an event, while the keys
> 
> 	Z X C V M , .
> 
> don't.
> 

It is exactly the same on my FR keyboard; the bottom row is:
[Shift] < W X C V B N ,  ; : ! [Shift]
With the left and right Shift keys held down, the keys:
< B N !
generate an event, while the keys
W X C V , ; : !
don't.

>More expensive keyboards (e.g. some "gaming" keyboards) avoid this
>problem by adding diodes in series with (some of) the switches, so
>that current can only flow from the rows to the columns, and not
>vice-versa. But that adds to the cost, and most modern keybards are
>nothing if not cheap.

Yes, my keyboard is very cheap and it could explain why it does not handle these combinations.