Rotate monitor image on 3B+ Ubuntu Mate 18.04?

[taylorkh]

I just hooked up a new (to me) refurbished Dell 1280 x 1024 monitor to a 3B+. $33 US delivered! As the monitor can pivot so as to present a Portrait layout 1024 x 1280 I decided to give it a try. I found that the monitor configuration under System; Preferences; Hardware; Display said the monitor was "Unknown" although the resolution is correctly detected. None of the setting can be changed including Rotation. I tried "Detect Monitors" but this did nothing.

Is this just a limitation of the Pi?

TIA,

Ken

[aBUGSworstnightmare]

Do you want to change it on the fly or simply use your screen portrait all the time? If second option then try to change it via config.txt

display_hdmi_rotate=x, where x can be one of the folllowing:
display_hdmi_rotate result
0 no rotation
1 rotate 90 degrees clockwise
2 rotate 180 degrees clockwise
3 rotate 270 degrees clockwise
0x10000 horizontal flip
0x20000 vertical flip

In case 'display_hdmi_rotate' isn't recognized try old 'display_rotate' comand

[taylorkh]

Thanks aBUGSworstnightmare,

I was just trying to change it on the fly. I can do that with nVidia and Intel graphics drivers. I had never tried on a Pi. I will give your approach a try although I will probably leave the monitor in landscape most of the time.

Ken

[aBUGSworstnightmare]

I've not tested latest revison of ubuntu mate so don't know atm if you can do it as 'you're used to'

[taylorkh]

I went back to 16.04. It does not provide for on-the-fly changing of display settings either.