# How do I expand to full screen on an external monitor?



## bxbzq (Mar 31, 2021)

Hi,
How do I expand to full screen on an external monitor under console? The configuration:
T400 built-in display has resolution 1280x800. 13.0 RC3 is running on it.
A 4K external monitor, actually a TV display, is connected to the laptop via VGA->HDMI adapter and cable.
I don't need 4K resolution on the external monitor, 1920x1080 would be great, but i wanna a full screen. Now the problem is only part of the TV display has content. Folloiwng is added to /boot/loader.conf:
kern.vt.fb.modes.LVDS="1280x800"
kern.vt.fb.modes.VGA-0="1920x1080"
It doesn't change anything. The LVDS and VGA-0 are what I get from %xrandr when in X.

I can accept only the external monitor is enabled and the built-in display goes to sleep.

Thanks for any help.


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## Mjölnir (Mar 31, 2021)

3 thoughts:

Using a VGA-HDMI cable is suboptimal.  You have better chances to get good results with HDMI-HDMI or display port-HDMI.  IIUC, the VGA signal is analog, the others are pure digital signals/protocols.
The TV might not support all the same resolutions than a computer monitor; you'll have to _try & error_.  IMHO you should start with the max. resolution.
You'll have to adjust your X11 fonts DPI accordingly to the use case (distance TV-eye).  See e.g. Qt's _HiDPI_ option (`EnableHiDPI=true` in sddm.conf(5)).


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## Minbari (Mar 31, 2021)

Run `dmesg` to get your output source name correctly.


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## balanga (Mar 31, 2021)

I had a problem trying to get the output from my computer centred on my screen and looked at all sorts of FreeBSD configuration options, but eventually discovered the Menu option of my TV remote which had an option to adjust the picture...

Helped me... but might not apply to you...


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## Mjölnir (Mar 31, 2021)

I forgot: maybe also use the TV's configuration menu.  The resolutions have to match somehow.


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## bxbzq (Apr 1, 2021)

Minbari said:


> Run `dmesg` to get your output source name correctly.


Good point. #dmesg gives me LVDS-1 and VGA-1. So I updated the /boot/loader.conf, but unfortunately it didn't change anything.


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## bxbzq (Apr 1, 2021)

Mjölnir said:


> 3 thoughts:
> 
> Using a VGA-HDMI cable is suboptimal.  You have better chances to get good results with HDMI-HDMI or display port-HDMI.  IIUC, the VGA signal is analog, the others are pure digital signals/protocols.
> The TV might not support all the same resolutions than a computer monitor; you'll have to _try & error_.  IMHO you should start with the max. resolution.
> You'll have to adjust your X11 fonts DPI accordingly to the use case (distance TV-eye).  See e.g. Qt's _HiDPI_ option (`EnableHiDPI=true` in sddm.conf(5)).


The laptop only has VGA port as graphics output, and max resolution a VGA can give is 1920x1080.


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## bxbzq (Apr 1, 2021)

balanga said:


> I had a problem trying to get the output from my computer centred on my screen and looked at all sorts of FreeBSD configuration options, but eventually discovered the Menu option of my TV remote which had an option to adjust the picture...
> 
> Helped me... but might not apply to you...



This looks the way to go. So far I could make full screen by adjusting setting to go _fit to the display_. But the result is the screen is offset horizontally a lot on the display. Only about half of the screen is shown on the TV. Vertically it's fine. Funny thing is I could move vertically but not horizontally, option box being greyed out. I suppose this is related to TV setting, not BSD system.


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## Snurg (Apr 1, 2021)

bxbzq said:


> The laptop only has VGA port as graphics output, and max resolution a VGA can give is 1920x1080.


This is wrong. Your thingy has max res 2048x1536 @ 75 Hz refresh.



bxbzq said:


> This looks the way to go. So far I could make full screen by adjusting setting to go _fit to the display_.


Doesn't your TV have an Overscan option? Then it might be unusable for your purpose.


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## bxbzq (Apr 1, 2021)

Snurg said:


> This is wrong. Your thingy has max res 2048x1536 @ 75 Hz refresh.


The 1920x1080 is the max I got from %xrandr, also from settings/display in XFCE. 
This is a bit mess, I think now it is the ATI3450 card working, because I disabled the integrated intel card in BIOS. I'll check later.  The thing is, if intel 4500MHD can output 2048x1536, the ATI3450 should be able to do higher.


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## SirDice (Apr 1, 2021)

bxbzq said:


> via VGA->HDMI adapter





bxbzq said:


> But the result is the screen is offset horizontally a lot on the display. Only about half of the screen is shown on the TV. Vertically it's fine. Funny thing is I could move vertically but not horizontally, option box being greyed out. I suppose this is related to TV setting, not BSD system.



That's probably your VGA to HDMI adapter that's doing that. The adapter has to convert the analog VGA signal, with a vertical and horizontal refresh signal and map this to a digital "viewport" that's shown on your TV. That analog display can be moved left/right and up/down, stretched horizontally and vertically, a good converter has options to move or stretch the resulting image. The HDMI output is a digital signal that could output in different resolutions and your TV scales that to the actual screen.


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