man fbset Command

Man page for apt-get fbset Command

Man Page for fbset in Linux

Ubuntu Man Command : man fbset

Man Fbset  Command

This tutorial shows the man page for man fbset in linux.

Open terminal with 'su' access and type the command as shown below:
man fbset

Result of the Command Execution shown below:

fbset(1)                                                              Linux frame buffer utils                                                              fbset(1)

fbset show and modify frame buffer device settings

fbset [options] [mode]

fbset is a system utility to show or change the settings of the frame buffer device. The frame buffer device provides a simple and unique interface to access
different kinds of graphic displays.

Frame buffer devices are accessed via special device nodes located in the /dev directory. The naming scheme for these nodes is always fb/ or fb, where
n is the number of the used frame buffer device.

fbset uses an own video mode database located in /etc/fb.modes. An unlimited number of video modes can be defined in this database. For further information
see fb.modes(5).

If no option is given, fbset will display the current frame buffer settings.

General options:

help, h
display an usage information

test don't change, just test whether the mode is valid

show, s
display the video mode settings. This is default if no further option or only a frame buffer device via fb is given

info, i
display all available frame buffer information

verbose, v
display information what fbset is currently doing

version, V
display the version information about fbset

xfree86, x
display the timing information as it's needed by XFree86

Frame buffer device nodes:

all, a
change all virtual consoles on this device

device gives the frame buffer device node. If no device via fb is given, /dev/fb/0 or /dev/fb0 is used

Video mode database:

set an alternative video mode database file (default is /etc/fb.modes), see also fb.modes(5)

Display bitfield colors:

each in length or length/offset color format

Display geometry:

set visible horizontal resolution (in pixels)

set visible vertical resolution (in pixels)

set virtual horizontal resolution (in pixels)

set virtual vertical resolution (in pixels)

set display depth (in bits per pixel)

select nonstandard video mode

geometry, g ...
set all geometry parameters at once in the order , e.g. g 640 400 640 400 4

make the physical resolution match the virtual resolution

Display timings:

set the length of one pixel (in picoseconds). Note that the frame buffer device may only support some pixel lengths

set left margin (in pixels)

set right margin (in pixels)

set upper margin (in pixel lines)

set lower margin (in pixel lines)

set horizontal sync length (in pixels)

set vertical sync length (in pixel lines)

timings, t ...
set all timing parameters at once in the order , e.g. t 35242 64 96 35
12 112 2

Display flags:

accel {false|true}
set hardware text acceleration enable

hsync {low|high}
set the horizontal sync polarity

vsync {low|high}
set the vertical sync polarity

csync {low|high}
set the composite sync polarity

gsync {false|true}
set synch on green

extsync {false|true}
enable or disable external resync. If enabled the sync timings are not generated by the frame buffer device and must be provided
externally instead. Note that this option may not be supported by every frame buffer device

bcast {false|true}
enable or disable broadcast modes. If enabled the frame buffer generates the exact timings for several broadcast modes (e.g. PAL
or NTSC). Note that this option may not be supported by every frame buffer device

laced {false|true}
enable or disable interlace. If enabled the display will be split in two frames, each frame contains only even and odd lines
respectively. These two frames will be displayed alternating, this way twice the lines can be displayed and the vertical fre
quency for the monitor stays the same, but the visible vertical frequency gets halved

double {false|true}
enable or disable doublescan. If enabled every line will be displayed twice and this way the horizontal frequency can easily be
doubled, so that the same resolution can be displayed on different monitors, even if the horizontal frequency specification dif
fers. Note that this option may not be supported by every frame buffer device

Display positioning:

move {left|right|up|down}
move the visible part of the display in the specified direction

set step size for display positioning (in pixels or pixel lines), if step is not given display will be moved 8 pixels horizon
tally or 2 pixel lines vertically

To set the used video mode for X insert the following in rc.local:

fbset fb /dev/fb0 vga

and make the used frame buffer device known to X:

export FRAMEBUFFER=/dev/fb0


fb.modes(5), fbdev(4), /usr/share/doc/fbset/FAQ

Geert Uytterhoeven

Roman Zippel
man files

2.1 2006 01 18 fbset(1)

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Apt Get Commands