/usr/share/X11/xorg.conf.d/10-monitor.conf
Section "Monitor"
  Identifier "CRT-0"
  HorizSync 14-20
  VertRefresh 40-70
  Option "DMPS" "False"
  Option "DefaultModes" "False"
  UseModes "CRTmodes"
EndSection

Section "Screen"
  Identifier "Screen0"
  Device "VGA-1-1"
  Monitor "CRT-0"
  DefaultDepth 24
  SubSection "Display"
    Depth 24
  EndSubSection
EndSection

Section "Modes"
  Identifier "CRTModes"
# 1024x768x60.00 @ 15.750kHz
    Modeline "1024x576x24.96"  19.404000  1024 1056 1144 1232  576 587 593 631  -HSync -VSync      interlace
# 600x480x60.00 @ 15.625kHz
    Modeline "720x576x25.00"  13.875000  720 744 808 888  576 586 592 625  -HSync -VSync interlace
# 800x600x50.00 @ 15.750kHz
   Modeline "800x576x24.96"  15.120000  800 824 896 960  576 587 593 631  -HSync -VSync     interlace

Modeline "512x288_50,0Hz 15,7KHz (60Hz)" 9.922 512 520 567 632 288 291 294 314  -hsync -vsync
Modeline "PAL  768x288 (50Hz)" 14.726 768 790 859 944 288 290 293 312 -hsync -vsync
Modeline "PAL  720x288 (50Hz)" 13.853 720 741 806 888 288 290 293 312 -hsync -vsync
Modeline "NTSC 640x240 (60Hz)" 12.312 640 662 719 784 240 244 247 262 -hsync -vsync
Modeline "NTSC 720x240 (60Hz)" 13.820 720 744 809 880 240 244 247 262 -hsync -vsync

EndSection