Solution for Sis video and Ubuntu 16.04 (how to get > 640x480)

If you are one of the people who has an older laptop that uses the sis video chipset you may have ran into the same issue I did.   When I initially installed chaletos the best resolution I could get was 1024x768@61hz when it should have  been 1280x768@60hz.  After I installed all available updates and rebooted the available resolution dropped to 640x480@60hz and ONLY 640x480.   The solution after much reading is to place a custom xorg.conf in /etc/X11.  I am including it here.  This will allow the full 1280x768 resolution you should have.  This is verified to work on an acer aspire 3000 series but since many older laptop's used the sis chipset I'm leaving the topic generic.

Copy/paste the following to /etc/X11/xorg.conf on your sis video device. (you can verify what video chipset your device uses by doing a "lspci -k"

Code:


Section "Device"
  Identifier "Generic Video Card"
    VendorName  "Silicon Integrated Systems [SiS]"
        BoardName   "771/671 PCIE VGA Display Adapter"
    Busid "PCI:1:0:0"
    Driver "vesa"
    Screen 0
        Option "UseFBDev" "true"
        Option "DPMS"
        Option "ShadowFB"
        Option "MaxXFBMem"
        VideoRam 262016
        Option "RenderAccel" "true"
        Option "AllowGLXWithComposite" "true"
        Option "backingstore" "true"
        Option "AddARGBGLXVisuals" "True"

EndSection

Section "Monitor"
    Identifier    "Configured Monitor"
    Vendorname    "Generic LCD Display"
    Modelname    "LCD Panel 1280x800"
    HorizSync 20-107
        VertRefresh 50-185
  modeline  "800x600@56" 36.0 800 824 896 1024 600 601 603 625 +hsync +vsync
  modeline  "800x600@60" 40.0 800 840 968 1056 600 601 605 628 +hsync +vsync
  modeline  "1280x768@60" 80.14 1280 1344 1480 1680 768 769 772 795 -hsync +vsync
  modeline  "1280x720@60" 74.48 1280 1336 1472 1664 720 721 724 746 -hsync +vsync
  modeline  "1280x800@60" 83.46 1280 1344 1480 1680 800 801 804 828 -hsync +vsync
    Gamma    1.0
EndSection

Section "Screen"
    Identifier    "Default Screen"
    Monitor        "Configured Monitor"
    Device        "Configured Video Device"
    Defaultdepth    24
    SubSection "Display"
        Depth    24
        Virtual    1280    768
        Modes        "1280x768@60"    "1280x720@60"    "800x600@60"    "1280x800@60"    "800x600@56"
    EndSubSection
EndSection

Section "Module"
    Load "dri"
    Load "dbe" # Double-Buffering Extension
    Load "v4l" # Video for Linux
    Load "extmod"
    Load "type1"
    Load "freetype"
    Load "glx" # 3D layer
    Load "GLcore"
    Load "i2c"
    Load "bitmap"
    Load "ddc"
    Load "int10"
    Load "vbe"
    Load "speedo"
    Load "record"
EndSection

Section "DRI"
        Mode 0666
EndSection