[PaulDavisThe1st]

related to TFA but different: does anyone know how to xrandr to arrange 3 screens into this arrangement:

                 S C R E E N T H R E E
                 screen one  screen two

so that moving the mouse vertically from screen 1 or 2 enters screen 3?

That is:

  screen one LEFT-OF screen two
  screen one BELOW screen three
  screen two BELOW screen three

Last time I tried this, it did not work (I assume because xrandr makes assumptions about physical monitor size)

[goosedragons]

I think for that kind of setup you have to specify based on pixels directly rather than relative. I think the "-pos" argument and you give the coordinates. It creates one giant virtual display (it's always a rectangle) that can accommodate the total resolution of all your displays so you might have to do some math to get it how you want. You could also try one of the GUI front ends to make a config for you like arandr.

[PaulDavisThe1st]

Great advice, thanks! arandr got me setup as desired, using -pos.