Samsung TV monitor with OS X El Capitan on mac mini displays not enough of the content. I do not get the top control bars, It worked fine before I upgraded from OS x 10.6.8.

I can only access the top control bar by taking the mouse atop the screen and quessing where to click. I have checked the display options on systems parameters and see no options. Somehow it does know it is a Samsung display. The connnection is HDMI. Is there a way to move the control bar, so it becomes visible? It may be that my mac mini 3,1 isn't supported, but the picture looks great and I have no problems with streaming tv to the screen size, I just can't see the entire desktop. The Samsung is an SUHD 2015 model

I have looked at the display option in the about my mac area and it says Samsung display 30.5" (1920x1080) NVIDIA GeForce 9400 256 MB graphics. Don't see how to change it, even if it would do any good. Is this an option in the TV that feeds through the HDMI? Again, worked fine in the old OS