: ''A mode line may also refer to a line for the

Emacs Emacs , originally named EMACS (an acronym for "Editor MACroS"), is a family of text editors that are characterized by their extensibility. The manual for the most widely used variant, GNU Emacs, describes it as "the extensible, customizable, s ...

and Vim editors that provides information about the file and modes.'' A modeline is a configuration line in

xorg.conf The file xorg.conf is a file used for configuring the X.Org Server X.Org Server is the free and open-source implementation of the X Window System display server stewarded by the X.Org Foundation. Implementations of the client-side X Window ...

or the

XFree86 XFree86 is an implementation of the X Window System. It was originally written for Unix-like operating systems on IBM PC compatibles and was available for many other operating systems and platforms. It is free and open source software under the X ...

configuration file In computing, configuration files (commonly known simply as config files) are computer file, files used to configure the Parameter (computer programming), parameters and Initialization (programming), initial settings for some computer programs. T ...

(XF86Config) that provides information to the

display server In computing, a windowing system (or window system) is software that manages separately different parts of display screens. It is a type of graphical user interface (GUI) which implements the WIMP (windows, icons, menus, pointer) paradigm for ...

about a connected

computer monitor A computer monitor is an output device that displays information in pictorial or textual form. A discrete monitor comprises a visual display, support electronics, power supply, housing, electrical connectors, and external user controls. The di ...

television Television, sometimes shortened to TV, is a telecommunication medium for transmitting moving images and sound. The term can refer to a television set, or the medium of television transmission. Television is a mass medium for advertisin ...

and how to drive it at a specified

display resolution The display resolution or display modes of a digital television, computer monitor or display device is the number of distinct pixels in each dimension that can be displayed. It can be an ambiguous term especially as the displayed resolution is ...

. The Modeline is based on the

Generalized Timing Formula Generalized Timing Formula is a standard by VESA which defines exact parameters of the component video signal for analogue VGA display interface. The video parameters defined by the standard include horizontal blanking (retrace) and vertical blank ...

or the

Coordinated Video Timings Coordinated Video Timings (CVT; ''VESA-2013-3 v1.2'') is a standard by VESA which defines the timings of the component video signal. Initially intended for use by computer monitors and video cards, the standard made its way into consumer television ...

standards produced by

VESA VESA (), formally known as Video Electronics Standards Association, is an American technical standards organization for computer display standards. The organization was incorporated in California in July 1989To retrieve the information, searc ...

. Modelines are now rarely used, but

and the Xorg Server still allow them to be set should the

EDID Extended Display Identification Data (EDID) and Enhanced EDID (E-EDID) are metadata formats for display devices to describe their capabilities to a video source (e.g. graphics card or set-top box). The data format is defined by a standard published ...

information be inadequate.

Syntax

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

pixel clock In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a raster image, or the smallest point in an all points addressable display device. In most digital display devices, pixels are the sm ...

megahertz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or Cycle per second, cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, me ...

. Then follow four numbers that together specify the ''x''-resolution (width) and related parameters, and four numbers that specify the ''y''-resolution (height). * Modeline syntax: * Flags (optional): 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: :

\mathrm

\mathrm

(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

front porch A porch (from Old French ''porche'', from Latin ''porticus'' "colonnade", from ''porta'' "passage") is a room or gallery located in front of an entrance of a building. A porch is placed in front of the facade of a building it commands, and form ...

sync pulse Analog television is the original television technology that uses analog signals to transmit video and audio. In an analog television broadcast, the brightness, colors and sound are represented by amplitude, phase and frequency of an analog s ...

, and back porch timings. The resulting

refresh rate The refresh rate (or "vertical refresh rate", "vertical scan rate", terminology originating with the cathode ray tubes) is the number of times per second that a raster-based display device displays a new image. This is independent from frame rate ...

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

interlaced Interlaced video (also known as interlaced scan) is a technique for doubling the perceived frame rate of a video display without consuming extra bandwidth. The interlaced signal contains two fields of a video frame captured consecutively. This ...

and

double scan A flicker fixer or scan doubler is a piece of computer hardware that de-interlaces an output video signal. The flicker fixer accomplishes this by adjusting the timing of the natively interlaced video signal to suit the needs of a progressive ...

modes. In most situations they will not be required.

Obsolescence

Modelines may no longer be necessary in XFree86 versions 4 and higher,XFree86 Video Timings HOWTO: 2. Why This HOWTO Is Obsolete
/ref> since for many monitors and

HDTV High-definition television (HD or HDTV) describes a television system which provides a substantially higher image resolution than the previous generation of technologies. The term has been used since 1936; in more recent times, it refers to the g ...

s they are now calculated by the X server at startup based on two factors: * other, more generic and intuitive, settings in the server configuration file * monitor capabilities acquired via an

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

s, it will be necessary to create a modeline to get the setting right. The EDID information can be obtained by using the command "" and looking at /var/log/XFree86.0.log.

Syntax

Obsolescence

See also

References

External links