I am hooked up to a tv via hdmi. I need to shrink the vertical size because I am losing about 10 pixels top and bottom. As that is where toolbars and panels are without their controls I have a very hard time accessing them. I do know that in getting the tv first working I did see sliders that did that job, but as I did not need them at the time I did not touch them but now I can not remember where I saw them. I am using KDE5 as my desktop.