BANGHO MOV notebooks

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linuc
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Iscritto: 10/17/2021

Does anyone know about BANGHO MOV notebooks? I have a very old one and the screen display is slightly distorted. For example, a circle is an oval, slightly wider than high.

Are there any special drivers for BANGHO MOV, or how can I solve the problem? With RandR?

I have Trisquel Mini installed, latest version.

Magic Banana

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Iscritto: 07/24/2010

In the screen settings of your desktop environment, isn't there listed an appropriate resolution?

linuc
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Iscritto: 10/17/2021

No, unfortunately not. That's the problem. Linux does not recognize the possible screen resolution, because the notebook has an outdated chip set, which is not very well supported. I suspect that my screen has a resolution of 1280x800, but the driver provides an image of 1024x768, which is then distorted. Ok, that's my guess.

Magic Banana

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Iscritto: 07/24/2010

Executing xrandr in a terminal lists the available resolutions:
$ xrandr
Anything better there?

linuc
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Iscritto: 10/17/2021

I have been practicing with xrandr in the meantime, but so far unsuccessfully. I am getting various error messages. Perhaps this is also due to the problem with the chip set and the driver. I was able to generate another screen resolution, but then could not activate it. Also the scale option did not work.

Another reason could be the BIOS settings.

linuc
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Iscritto: 10/17/2021

A first little help for solving this problem. I haven't tried it yet and I expect that not everything will work as it is in the article, because Linux is no longer what it was in 2015. But if someone wants to try.

original:

https://info.wsouza.com.br/2015/01/novidades-sobre-sis-mirage-3-no-ubuntu.html

more:

https://forums.debian.net/viewtopic.php?f=6&t=120734

linuc
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Iscritto: 10/17/2021

In the meantime, I have taken a few small steps forward. With this guide I could install the old drivers for SIS:

https://easylinuxtipsproject.blogspot.com/p/sis.html

So far I have not done any tests with it.

I also succeeded with "vesa" and an xorg.conf to obtain a resolution of 1280x768. But then the screen is distorted in height, so a circle is an oval, higher than wide. With the automatically created resolution of 1024x768, it is the opposite, that is, wider than high. Thus, the optical resolution must be between 1024 and 1280.

Now I learned in the manual that my screen is a WXGA with an aspect ratio of 16:10. Today 16:9 is common. So here lies the real problem.

Either the SIS drivers are able to generate a corresponding resolution, or I have to try to change the resolution with xrandr, as in this example:

https://unix.stackexchange.com/questions/596887/how-to-scale-the-resolution-display-of-the-desktop-and-or-applications

But there is a lot to read and test!

linuc
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Iscritto: 10/17/2021

Well, after further unsuccessful attempts to solve the problem with the distorted screen, I have the impression that it cannot be solved with X. The main problem is that Xrandr does not work correctly and produces error messages. I suspect that this is a problem of X.

I also realized that X is being replaced by Wayland and therefore I need a solution with Wayland and not with X.

At the moment I have a Debian 11 installed with the GNOME desktop, because it works completely with Wayland. After installation, I have a screen resolution of 1024x768 and the display is also distorted, so a circle is an oval, wider than high. But after all, the text is much clearer. Now I will try to find or install the right tools to get a better resolution (1280x800) and correct the distortion.

If it works at some point, I will try to work with Q4OS Trinity and Trisquel Mini (lightdm) also with Wayland, if this is already technically possible. And if not, I will switch the desktop on both to get Wayland.

Too bad I didn't find a solution with X. For the moment it would have served me.

linuc
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Iscritto: 10/17/2021

Two more suggestions from the Q4OS forum. I have not tried these. Too much effort.

https://wiki.archlinux.org/title/SiS

https://unix.stackexchange.com/questions/215282/sis-771-671-graphical-card-is-there-some-unix-like-os-distro-that-works-correct

Maybe one day I will find a solution for Wayland, because apparently this is the new way!

linuc
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Iscritto: 10/17/2021

After a few hours of further attempts, I actually took it a step further. With the help of this manual it was possible to get a resolution of 1440x900 (16:10) on Trisquel Mini (lightdm) and Debian 11 (GNOME). In Debian 11, wayland also detects the resolution when the sis driver is installed. But the picture is still distorted in all cases!

https://gist.github.com/fevangelou/46a2885233c45011ad5c8752f18eac73

I removed the cover of my LCD screen and looked to see what kind of screen it is. It is a WXGA+, so 1440x900 (16:10).

Distortions with such screens are known. Apparently the problem had been solved with "915resolution", but the package does not seem to exist anymore. "xserver-xorg-video-sis" is also sometimes mentioned, but also no longer exists, or is no longer up-to-date. So the attempt remains with "xserver-xorg-video-sisusb"?

Does anyone have another tip?

Cyberhawk

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Iscritto: 07/27/2010

Your patience and persistence is admirable, but I'm sorry to say - no idea how to solve your problem. Never had to deal with this kind of hardware myself.

Back when I had a radeon video card which was difficult to get to work sometimes, I remember being able to just manually enter the desired resolution in xorg.conf.

This was way back when. Wasn't even on Trisquel back in that time, but on Ubuntu.

I hope you will find some workaround

linuc
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Iscritto: 10/17/2021

@Cyberhawk

Yes, the size of the LCD is not recognized. Only the maximum run-up of 1440x900. But not the physical dimension of a 14.1 screen, which is about 305x190 millimeters. This then results in a DPI of only 96 being used. With "displaySize" I have now set the real size, but the image is still distorted. Apparently the input is overwritten? Maybe I need to turn something off or turn it on with an "option"? Or am I trying to do it with a "wrong" size in millimeters? My picture screen is 16:10, but it is said that such screens are sometimes driven at 16:9. Ok, I have enough things to test :-)

"Note: This calculation works for monitors with square pixels; however, there is the rare monitor that may compress aspect ratio (e.g 16:10 aspect resolution to a 16:9 monitor). If this is the case, you should measure your screen size manually."

from here:

https://wiki.archlinux.org/title/xorg#Monitor_settings

damidu
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Iscritto: 03/30/2021

Hi

Do you know what your graphic card is? With some graphic cards you need non free firmware (linux-firmware package) to work at the full potential.

If the notebook is really old and not produced anymore, it could happen that the graphical driver maybe dropped.

linuc
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Iscritto: 10/17/2021

Yes, ist is a SIS671 or maybe a SIS672. Driver for SIS I have installed.

linuc
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Iscritto: 10/17/2021

FINALLY IT WORKED!

Well, after a few more tests I came to a good result. Here is my xorg.conf:

Section "Device"
Identifier "Configured Video Device"
Driver "sis671"
EndSection

Section "Monitor"
Identifier "Configured Monitor"
displaySize 305 189# In millimeters
EndSection

Section "Screen"
Identifier "Default Screen"
Monitor "Configured Monitor"
Device "Configured Video Device"
EndSection

Since my LCD display was not recognized correctly, I had to enter the size in millimeters. X takes the the correct value (without plastic cover, which is somewhat overlapping). This leads to this result:

trisquel@trisquel-M540SS:~$xdpyinfo / grep -e dimensions -e resolution
dimensions: 1440x900 pixels (307x191 millimeters)
resolution: 119x120 dots per inch
trisquel@trisquel-M540SS:~$

Without the instruction "displaySize" I get a much larger, wrong dimension and only 96 DPI. Now the screen display is very good, sharp and no longer distorted.

Here again my whole procedure:

1. Install SIS Driver using this method (xorg 1.20, or change value in script)

https://gist.github.com/fevangelou/46a2885233c45011ad5c8752f18eac73

2. Determine LCD size. Either measure directly or look up a list on the Internet. Here is one in German:

https://www.bardzki.com/magic/standardgroessen

3. Adjust xorg.conf with this line (use numbers according to your screen) in "monitor" section

DisplaySize 305 189 # In millimeters

4. reboot

5. Check the result with:

xdpyinfo | grep -e dimensions -e resolution

6. If the screen display is still distorted, change the millimeter data, reboot, check again.

The solution works with Trisquel Mini 10, lightdm desktop. I assume that it will also work with Q4OS Trinity. For Debian 11, GNOME with wayland, it may require a different solution, for example with a bootcode to set the "displaySize". I will test it soon.

Thanks for all the help and tips!

Edit: Successfully installed on Q4OS Trinity.

Cyberhawk

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Iscritto: 07/27/2010

That's some project you've done there! Congrats, and enjoy your Trisquel on a sharp and undistorted display!