在 Ubuntu 11.10 新增自己需要的螢幕解析度

手邊一台舊電腦重灌 Ubuntu 11.10 後抓不到一台 23" 螢幕，無法自動偵測，解析度也變成只有兩個可以選：1024x768 和 800x600。後來找到手動的解法。

例如我這次想要加入的是 1680x1050 (16:10) 解析度 @ 更新頻率 60：

$ gtf 1680 1050 60 -x

  # 1680x1050 @ 60.00 Hz (GTF) hsync: 65.22 kHz; pclk: 147.14 MHz
  Modeline "1680x1050_60.00"  147.14  1680 1784 1968 2256  1050 1051 1054 1087  -HSync +Vsync

編輯 /etc/X11/xorg.conf （原本不存在這個檔案）

$ sudo vim /etc/X11/xorg.conf
Section "InputDevice"
Identifier "Generic Keyboard"
Driver "kbd"
Option "XkbRules" "xorg"
Option "XkbModel" "pc105"
Option "XkbLayout" "us"
EndSection

Section "InputDevice"
Identifier "Configured Mouse"
Driver "mouse"
Option "CorePointer"
EndSection

Section "Device"
Identifier "Configured Video Device"
EndSection

Section "Monitor"
Identifier "Configured Monitor"
Vendorname "Generic LCD Display"
Modelname "LCD Panel 1024x900"
Horizsync 31.0-83.0
Vertrefresh 56.0 - 76.0
modeline "640x480@60" 25.2 640 656 752 800 480 490 492 525 -vsync -hsync
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 "1024x768@60" 65.0 1024 1048 1184 1344 768 771 777 806 -vsync -hsync
# 將剛才跑 gtf 產生的 Modeline 貼過來下面
Modeline "1680x1050_60.00"  147.14  1680 1784 1968 2256  1050 1051 1054 1087  -HSync +Vsync

Gamma 1.0
EndSection

Section "Screen"
Identifier "Default Screen"
Monitor "Configured Monitor"
Device "Configured Video Device"
Defaultdepth 24
SubSection "Display"
Depth 24
# 輸入自己想要的解析度，此例為 1680x1050
Virtual 1680 1050
Modes "1680x1050@60" "1024x768@60" "800x600@60" "800x600@56" "640x480@60"
EndSubSection
EndSection

Section "ServerLayout"
Identifier "Default Layout"
screen 0 "Default Screen" 0 0
EndSection
Section "Module"
Load "dri"
Load "v4l"
EndSection
Section "ServerFlags"
EndSection

重新開機後即可服用（切換過去） :)