Confused about video settings on Debian Squeeze

[nugget]

It seems I am stuck with big black bars at the top and bottom of my screen. I've been experimenting for hours with various settings in the config.exe but it makes no sense to me at all.

At first config.txt was blank and the pi automatically chose some kind of 576P resolution (I forget which), it looked pretty bad (everything was too big) and there were black borders at the top and bottom of the screen.

At the moment I have the following settings in my config.txt:

HDMI_mode=19

overscan_left=20

overscan_right=20

overscan_top=0

overscan_bottom=0

This gives me a display that fits perfectly horizontally and looks quite nice size-wise, but there are still those big black bars on the top and bottom. When I log into LXDE and look up the resolution it's 1144x624, this seems to have no relationship at all with the overscan settings. HDMI-mode=19 is supposed to be 1280x720, so with overscan_top and overscan_bottom both set to zero the vertical resolution should still be 720, not 624 like it is now? Also, I've no idea how the horizontal resolution is reduced from 1280 to 1144 based on left/right overscan settings of 20...

If I just set  disable_overscan=1 then I apparently get the correct resolution of 1280x720, but the output is too large on my display (the taskbar is only just visible in LXDE) which makes it unusable. This is the only setting that gets rid of those top and bottom bars however

I think I could live with the display as it is at the moment, but if anybody can help clear this my confusion I would really appreciate it.

I'm using cheap HDMI TV that I inherited so I'm not sure about native resolutions etc, and as far as I can tell there are no settings on the TV that can tinkered with.

[dom]

Default overscan is 32 on all sides for SD and 48 for HD (1280 or wider).
You can specify negative overscan to make it less that the default e.g. -16.

[nugget]

Awesome thanks, all becomes clear with those default values. Set the top and bottom to -34 and -30 and the sides to zero and it looks much better now.

[bamboozled]

Can someone explain this in step-by-step Newbie English please? Like, what is the config.txt file, where do I find it, exactly what do I click to edit it...

Or is there an ABSOLUTE Absolute Beginners forum that I"ve missed?

[dom]

http://elinux.org/RPi_config.txt

[jamesh]

bamboozled said:


Can someone explain this in step-by-step Newbie English please? Like, what is the config.txt file, where do I find it, exactly what do I click to edit it...

Or is there an ABSOLUTE Absolute Beginners forum that I"ve missed?


Dom's pointed you to the specific page you need, but for general Raspi advice the Wiki does have a lot of information.