XF86Config-4 params for LCD monitor L1720P

Hi,

how can I figure out correct value in /etc/X11/XF86Config or /etc/X11/XF86Config-4 in Section ''Monitor''
for my LG L1720P 17" monitor, in order to get it running with native resolution 1280x1024 @ 75Hz
I have: Knoppix 3.7, LG L1720P , ATI Rage Fury Pro VIVO 32Mb

Currently I found following values from Google:
---
Section ''Monitor''
Identifier ''monitor1''
VendorName ''Generic''
ModelName ''Flat Panel 1280x1024''
HorizSync 31.5-67
VertRefresh 50-75

# 1280x1024 @ 61 Hz, 64.2 kHz hsync
ModeLine ''1280x1024'' 110 1280 1328 1512 1712 1024 1025 1028 1054
---

It is running @ 60Hz,
I understand that I need to change values of MODELINE section? Or HorizSync and VertRefresh ?
how could I calculate correct values for running @ 75Hz (like in windows).

And what is the difference between: /etc/X11/XF86Config and /etc/X11/XF86Config-4 - where should I make changes?

Thanks in advance

Howdy alarm


>>
how can I figure out correct value in /etc/X11/XF86Config
or /etc/X11/XF86Config-4 in Section ''Monitor''
for my LG L1720P
17" monitor, in order to get it running with native
resolution 1280x1024 @ 75Hz
I have: Knoppix
3.7, LG L1720P , ATI Rage Fury Pro VIVO 32Mb
>>

Don't know the monitor, but i do know of a good
program that can generate a working "ModeLine" to start
tweaking from.

--------------------------------
gtf.c Generate mode timings using the GTF Timing
Standard

gcc gtf.c -o gtf -lm -Wall

Copyright (c) 2001, Andy Ritger [email protected]
All rights reserved.
--------------------------------

found at ...

http://sh.nu/nvidia/gtf.php


If the monitor is a LCD type, they can be very specific
in the refresh rate used, so i hear. So, check its
manual closely for its' recommended optimisations etc.

Just dload the file. Compilation is very easy, then
run it. Without parameters it will display a simple
help explanation on usage.

A couple of things to note though ...

When tweaking the numbers that relate to the
horizontal timings, do it in multiples of "8". Thats because of a historical quirk
thats flowed into the chipsets used concerning the number
of bits used to measure horizontal "ModeLine" numbers.
Basically the lower three bits are missing. So all
numbers have got to go in as 8 x's

Verticle timing numbers don't matter there.

When you move the gates to the left, the screen
will go right, and visa-versa.

example only:

Modeline "800x600" 50.685 800 840 984 1056
600 601 606 627 +HSync +Vsync

If i shift "840 984" to the right, the screen will
move to the left, and it must be in multiples of "8"

If i shift "601 606" to the right, the screen will
go up. The 8x rule dosen't apply there.

By screen i don't mean the monitor screen. I mean the
displayed root window.

You may have to tweak it a bit if you get a margin
or such around that root window.

X does have gui tools also, like xvidtune, but i don't
like that program much. So i haven't used it
for ages.

It may well be fixed by now though :lol:

XF86Config-4 is the prefered file for X v4.x.x

XF86Config was used for v3.x.x

X will check for both, but use the dash 4 type over
the other if found.

If your really into Video-Timing stuff, E Raymond
has authoured an excellent HowTo on the issue.

One of the better HowTos', considering the
shocking state there in these days too.

Good Luck.

jm