I thought I had seen this in Antix - turns out it was in a dual-boot with Xubuntu. I didn't figure it out until I downloaded Xfce 4 into Antix 8.5. Once you do that, if you click Applications-system preferences-Xfce 4 settings manager-Desktop, you'll see controls for screen settings. I needed to find this as I lost my user manual for my Compaq CQ61 laptop. Does anyone know if there is a separate key command for this?