On Thursday 11 July 2019 14:35:54 Mike Bird wrote:
> On Thu July 11 2019 14:28:29 andre_debian@... wrote:
> > On my laptop computer , the keys F11 and F12,
> > adjusts the brightness of the screen.
> > But on Debian-Stretch with trinity, these two keys do nothing.
>
> I can't help you with F11 and F12 but if it's a 70% brightness
> you want you can put "xbacklight -set 70" in a file called
> ".xsessionrc" in your home directory.
>
> --Mike
>

If I read the original question aright, he wants to make the screen brightness 
adjustable: F11 for dimmer, F12 for brighter (probably). 

Can't you use some kind of specialized keyboard mapping to make these keys do 
what you want? 

It has been about ten years since I last tried something like this, so I fear 
getting drawn too deeply into this discussion, but ... anyway ... it could be 
that I will find this information useful again myself, for my own purposes. 

You ought to be able to change one or two keys to get them to do this. A quick 
search of the forums (e.g., "keyboard mapping debian ?") returns lots of 
pages. 

Bill