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View Full Version : What is generating the lines in xorg.conf



Perty
29th April 2006, 11:46 PM
I got (and a lot of other ppl too according to search in the forum and on google) a lot of lines added to my xorg.conf looking like this :

### Comment all HorizSync and VertSync values to use DDC:

What does it mean and what is writing those lines, and how do I get rid of them? It looks to me that there is someone who thinks I should uncomment the Horiz and Vert Sync but why? And what is DDC?

/Perty

Skunk Worx
30th April 2006, 04:07 AM
What does it mean
It looks like X configuration has gotten to the point where they can query the monitor settings rather than ask the user for the monitor type and model.


and what is writing those lines,
Probably the system-config-display command.


and how do I get rid of them?
They are comments, so they don't harm anything. You could edit them out I guess. My original xorg.conf had 3, my new one has only one. Not sure why.


It looks to me that there is someone who thinks I should uncomment the Horiz and Vert Sync but why?
It looks (to me) like they are putting a comment in the file to let you know that *you can* comment out the lines and use DDC if you choose to do so. Mine, by default, has the comment and the H/V freq lines still in place.

I think at some point Fedora might prefer to get the config values directly from the display, automatically, rather than maintaining a big database of all display models.

In such a case you could plug a new display in and it will just work.


And what is DDC?
http://en.wikipedia.org/wiki/Display_Data_Channel

Run '/usr/sbin/ddcprobe' and see what happens:

mine :

Videocard autoprobe results
Description: 
Memory (MB): 32

Monitor autoprobe results
ID: VSC9e19
Name: A91f+
Horizontal Sync (kHZ): 30-86
Vertical Sync (HZ) : 50-180
Width (mm): 360
Height(mm): 270

Perty
30th April 2006, 07:35 PM
Hmmm running ddcprobe gives me this:

[root@localhost ~]# ddcprobe

Videocard autoprobe results
Description: LG Electronics Inc. G72 Board - lg72m
Memory (MB): 128

Monitor autoprobe results
Monitor autoprobe failed.


But I realise I tested comment the Horiz and Vertical in xorg.conf looking like this now:

Section "Monitor"
#HorizSync 31.5 - 37.9
#VertRefresh 50.0 - 70.0
Identifier "Monitor0"
VendorName "HannStar"
ModelName "HSD150PK14-C"
Option "dpms"
EndSection

(the Vendor and ModelName did I found in the xorg.log and manually wrote)

And it worked and I havn't got those comments back, my feeling was that a comment was added every boot of the computer.. And it works like a charm anyway even if my ddcprobe won't give me the horiz and vertical sync..

Strange.. I think... But it's a lot of strange hidden features in Linux..

/Perty