XFree86 Modeline

A mode line may also refer to a line for the Emacs and Vim editors that provides information about the file and modes.

A modeline is a configuration line in

Modelines are now rarely used, but

Syntax

Each modeline has ten parameters, beginning with a label for the resolution being specified. The second parameter specifies the rate of the

• Modeline syntax: pclk hdisp hsyncstart hsyncend htotal vdisp vsyncstart vsyncend vtotal [flags]
• Flags (optional): +HSync, -HSync, +VSync, -VSync, Interlace, DoubleScan, CSync, +CSync, -CSync

Modeline "1600x1200" 155   1600 1656 1776 2048   1200 1202 1205 1263
#           (Label) (clk)     (x-resolution)        (y-resolution)
#                     |
#              (pixel clock in MHz)

Or, the modeline can be split into multiple lines for greater clarity

Modeline "1600x1200"  155  1600 1656 1776 2048
                           1200 1202 1205 1263

The horizontal and vertical frequencies can be calculated by:

${\displaystyle \mathrm {Hfreq=pclk/htotal} }$

${\displaystyle \mathrm {Vfreq=pclk/(htotal*vtotal)} }$ (field rate)

For interlace mode, (frame rate)=(field rate)/2, otherwise (frame rate)=(field rate).

The numbers after the width and height are used to determine the

or frame rate of the display can be determined by dividing the pixel clock frequency by the product of the horizontal and vertical field lengths. In this case, the display is operating at ${\displaystyle 155,000,000/(2048*1263)=59.92}$

Optionally, extra parameters for controlling the polarity of the horizontal and vertical sync pulses can be added. There are also options for

Obsolescence

Modelines may no longer be necessary in XFree86 versions 4 and higher,

• other, more generic and intuitive, settings in the server configuration file
• monitor capabilities acquired via an
  EDID
  query

EDID is not always completely accurate, and for some situations such as older or unusual display hardware or many

See also

• Raster scan
• Sync pulse

References

External links

• XFree86 Video Timings HOWTO
• The XFree86 Modeline Generator
• Modeline generator in C for download
• Online Modeline generator (with Ruby source)
• Colas XFree Modeline Generator
• Online Modeline Tool
• Video Timing Details
• MythTV Wiki Working With Modelines
• LCD/TV Modeline Database