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Author Topic: help me converting an fb.modes entry to exact modeline  (Read 3153 times)


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Offline gaula92Topic starter

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help me converting an fb.modes entry to exact modeline
« on: February 28, 2011, 03:17:08 PM »
Hello there

I'm using a new EFI-based Gentoo Linux system where the uvesafb framebuffer won't work anymore, but I need the old framebuffer videomodes in Xorg for emulation purposes.

Now I have this modeline, the original MS-DOS 320x200@85HZ mode wich has this entry in the /etc/fb.modes file:

mode "320x200 85Hz 16bit"
    geometry 320 200 320 200 16
    timings 60440 32 32 20 4 48 1
    double true

This mode works great in my lcd monitor, and makes DOS games under DOSBOX look exactly as they did back in the day, smooth scroll and all in the few ones having it.

However, when using an automatic perl program to convert the fb.mode entry to a modeline I got:

Modeline "320x200"         16.545  320 352 400 432  200 204 205 225 -hsync -vsync

...wich doesn't work. I've also tried generating the 320x200@85HZ mode with several modeline generators, and the resulting modes were "out of sync error" for my LCD.

So my question is: can you guys give me or help me to convert that fb.modes entry to an EXACT modeline equivalent?

What values do I need in HorizSync and VertRefresh in /etc/X11/xorg.conf?

It seems X DOES combine the modelines with those two values to get a given exact video mode...