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mattcallao
12-06-2007, 10:20 AM
Hi Guys!

I'm a newbie with kernel stuff and all that, could you guys help me with my problem.. I can't tweek my resolution when I use Knoppix 5.0 Live CD.... my card is an Intel(R) 82845G/GL/GE/PE/GV. Knoppix runs perfectly fine except the display goes back to it's lowest res.

I made a little research of my own and tried various "codes" like dpkg-reconfigure..., xmodule=vesa, screen=1024x768... etc.

Please help...

Thanks!

johnsfine
12-06-2007, 03:13 PM
I'm only a little ahead of you in understanding this (so if any experts are reading this, don't let my answer stop you from posting a better answer that would help both mattcallao and me). But until an expert answers:

The display behavior is mostly controlled by the file /etc/X11/xorg.conf

Knoppix seems to have its own method for examining your hardware and creating that file, which gives conservative settings on some displays and even worse (as you seem to get) on others. Short of remastering Knoppix, you need a way to replace that file with a better version between starting knoppix and starting X.

While experimenting, I used "knoppix 2". to stop the boot-up at level 2 in order to give a few commands to tweak the xorg.conf file, before typing "init 5" to continue the boot-up.

On one of my systems, the command "X -configure" produces decent results (on the other system X -configure hangs, so I need to reboot). If it works, it creates the file
/xorg.conf.new

So the commands I need are:
X -configure
cp /xorg.conf.new /etc/X11/xorg.conf
init 5

(Notice two of those X's are upper case).

If you have a hard drive or usb flash drive or other media available at boot time that Knoppix can read, you can put a script knoppix.sh on the root directory of that media and then start knoppix with "knoppix myconfig=scan". That will execute that script before knoppix does its automatic init 5. So you can use that instead of "knoppix 2" and manually typing the commands, to fix the xorg.conf file before X starts.

On my other computer, I had the harder task of manually editing the xorg.conf file, because I coundn't find any hardware probing method other than knoppix's that doesn't hang and knoppix's, while not hanging, produces wrong results. Obviously, I won't manually edit xorg.conf every time I boot knoppix, so I keep it on a usb flash drive with the script that copies it to /etc/X11. The hard part, which I've only partially solved, is figuring out what should go in that file.

On that computer, I have two display cards, each with one monitor. For each card I have come up with the xorg.conf file that will get the correct range of resolutions on the monitor and which works when that is the default card selected by the BIOS. But starting X always hangs when I attempt to use an xorg.conf file with both screens or I attempt to use the xorg.conf file for the screen that wasn't the BIOS default.

Windows XP has no trouble extending the desktop to the second monitor, so I know there is no fundamental hardware problem. Maybe I don't have the right drivers I need on the knoppix dvd or maybe I just didn't put the right things in the xorg.conf.

But as you just want to get the resolution right, that should be much simpler. Maybe "X -configure" will work. Otherwise, I had no trouble tweaking my xorg.conf to get the resolution right.

Maybe you can post the /etc/X11/xorg.conf file that knoppix creates, in order to get tweaking suggestions. On the computer where "X -configure" didn't work, I found the xorg.conf created by knoppix boot-up to be a good starting point. It just needed a few tweaks to fix the resolution.

mattcallao
12-07-2007, 11:11 AM
:o Thanks a lot johnsfine! I tried your script once and it worked perfectly! I don't know how deep you know Linux but in my case I have to say that your one WICKED dude! :twisted:

Thanks!

hal8000
12-12-2007, 10:21 AM
Another way to fix resolution problems is that when the CD starts, there is a boot prompt.
If your laptop require 1400 x 1050 then enter

screen=1400x1050


Also, an alternative to reconfiguring the Xserver is
dpkg --reconfigure xserver-xorg


@johnsfine: In your first paragraph you incorrectly give the location of xorg, it is as you correctly state later down /etc/X11/xorg.conf
I'm not sure how long you've been a linux user but you appear to be leaning at some accelerated rate, at this pace you may even
progress for bettere and greater things. I've been a linux user now for 6 years, and though I can create new kernels, I'm not a
programmer and struggle with some things. Regards.

mattcallao
12-13-2007, 06:45 AM
@johnsfine, I did the same thing with another computer, this time the res is 1152x684 and it didn't work :(

I tried doing screen=x, but Knoppix returned me an error asking me to hit <RETURN> or <SPACE>, if I hit <RETURN> it'll display a list of low res, and then I ended up selecting the most decent res I could use which is 840x6..

Any other ideas?

Appreciate it.

johnsfine
12-14-2007, 05:59 PM
screen=1400x1050

I assume you mean I should type that on the line with the knoppix command, where I now put the myconfig=scan
I haven't had time to try that yet. It doesn't sound right relative to what I've tried already nor relative to the documented options for Knoppix 5.1.1, but I'll try it.


Also, an alternative to reconfiguring the Xserver is
dpkg --reconfigure xserver-xorg

I guess I'll try that as well (on the computer where X -configure hangs)


In your first paragraph you incorrectly give the location of xorg

Thanks for catching that. I edited that post to fix that error.


I'm not sure how long you've been a linux user but you appear to be leaning at some accelerated rate, at this pace you may even
progress for bettere and greater things. I've been a linux user now for 6 years, and though I can create new kernels, I'm not a
programmer and struggle with some things.

I am a programmer. I started learning Linux a few times many years ago. I even managed to edit (in MS-DOS) some Linux device drivers for obscure equipment I was using then, to fix bugs and got that equipment working right. But I found I just don't have the right kind of memory for working with all the command line nonsense of Linux, and I find Linux man pages and other documentation to be even more beginner vicious than MS documentation. So each time I gave up on Linux quickly. In Windows, I can compensate for poor memory and poor typing skills with lots of customizations to right click menus. I'm not too happy with the right click menus in KDE, but they are a big step up from my previous attempts at using Linux without right click menus at all. Maybe I'll even figure out how to customize them.

johnsfine
12-27-2007, 05:24 PM
I set aside for a while trying to figure out knoppix on the two computers where I was doing that. Now I'm trying (which MUCH grief) to get Debian Linux running acceptably on a third computer where I don't have an DVD drive (My Knoppix is on DVD, not CD) but did have a spare 40Gb IDE drive.

But I wanted to at least report back here the results of trying what you suggested.


Another way to fix resolution problems is that when the CD starts, there is a boot prompt.
If your laptop require 1400 x 1050 then enter

screen=1400x1050


My notes from when I first started trying Knoppix indicate I tried that on both computers with a bunch of values for resolution (including the ones that ended up working by other means) and any value over 1024x768 resulted in 640x480 (not using "screen=" at all gives 1024x768).

After your suggestion, I tried again and only one computer ("B") behaves as my notes indicated. On system "A", that screen option on the Knoppix command works fine and gives access to any of the screen resolutions that monitor supports. So I could have been working at above the frustrating 1024x768 the whole time I was looking for better screen behavior. I'm sure I tried that several times and I have no idea now what I was doing wrong then.



Also, an alternative to reconfiguring the Xserver is
dpkg --reconfigure xserver-xorg


I don't think you gave that command correctly.
Knoppix didn't understand that command that way.
In my system "C" running Debian Linux, I used a command similar to that (following instructions I found elsewhere). That command was understood and processed (but didn't solve my problem). I didn't take notes on the exact syntax of that command, but it wasn't exactly what you said above, just similar.

Current display status on my three systems:

"A" I have two monitors on an Nvidia card plus one on an ATI card. The best support I've gotten so far was done by using "X -configure" to get a nearly correct xorg.conf file, then hand edit some details. It supports one monitor per card, with two simultaneous desktops. I can move the mouse between desktops, but can't move windows between desktops. I can get any resolution the monitors support.
I can't enable xinerama (to make one desktop across two monitors).
I can't enable the second monitor on the nv card (to have all three monitors working)

"B" I have one monitor each on an Nvidia card and an ATI card. The best support I've gotten so far (by manual editing the xorg.conf file knoppix produces by default) is to get all supported resolutions on one monitor per boot, the one initialized by the BIOS during boot (which can be selected in BIOS setup).
I can't get either display card to work when it wasn't the one intialized by the BIOS during boot.
Any attempts to use "X -configure" or to start X with a monitor that wasn't initialized by the BIOS or just about anything else I can think of trying, hangs the system such that the only way out is pull the power cord then reboot. There is never any error message to give a clue what went wrong.

"C" (with Debian Linux, not Knoppix) I have one monitor each on an Nvidia card and an ATI card. With everything I could find from debian, I was able to get only the ati card working and only when it was the one intialized by the BIOS. All other attempts gave fairly clear error messages and dumped me back to text mode. The ati driver basically complained that the card hadn't been initialized by the BIOS. The nv driver complained that the card wasn't there, despite it being the card in use in text mode and reported correctly by lspci and by the pci scan inside the X startup.
I then tried the newest linux driver from nvidia.com instead of an nvidia driver from debian.org. That had a user-friendly installer that told me my card needed a specific obsolete version of the nvidia driver instead.
I downloade (from nvidia.com) the user-friendly installer for that obsolete driver and ran it many times. It took much searching to find the command "/etc/init.d/gdm stop" to get the system in the state that installer wanted (I found lots of places other newbies asked how to stop X without going to single user mode and got wrong answers). When the installer complained that I needed "gcc" I made my best guess which of the many "gcc" choices in synaptic it needed. Apparently the correct guess. Similarly when it said it needed "libc". But when it said I needed "kernel-source" I was stuck for a long time. I found and tried lots of detailed but wrong instructions for using apt-get to get "kernel-source". Finally, I found someplace that said what I really needed is called "linux-source" rather than "kernel-source". That was then easy to get with synaptic. Then the installer worked. The tool nvidia provided for fixing the xorg.conf file left the ATI card's PCI address there (despite changing other card info), so starting X failed, but with a clear error message so I knew what to fix.
Now I can start X with the nvidia card even though it wasn't initialized by the BIOS.
I expect I can merge the two working xorg.conf files manually to get both monitors working together, maybe even with xinerama, but I haven't tried yet.

I expect knoppix on system "B" needs that same obsolete nvidia driver (it's a very similar nvidia card) to be able to use the nvidia card even when the BIOS initialized the ati card. But installing gcc and libc and linux-source is way too much for the usb stick that is my only writable media for knoppix in that computer. I'm not nearly linux expert enough to install the knoppix version of linux-source to system "C" in order to recompile the obsolete nvidia driver there, then copy just the compiled driver to the usb to use in system "B". (I understand the concept of that, but the details are beyond me).

mcintoshrobertb
01-16-2008, 04:10 PM
I had the same problem on my PC and as a work around I tried "fb1280x1024" on the boot command and finally it came up ok.

hal8000
01-23-2008, 11:05 AM
Sorry guys, some mistakes in my own information.

At the isolinux boot prompt, to boot to a particular resolution (only if your graphics card and monitor are capable of working at said resolution)

knoppix screen=1024x768

(Some commands dont use the prefix knoppix, others do).

To reconfigure an X session:

Drop out of current session:
At a terminal
sudo init 2

To reconfigure X:

sudo dpkg-reconfigure xserver-xorg


switch back to X

sudo init 5

Apologies for my previous post.

@johnsfine Great to know we have a programmer on this forum :)
I can write bash scripts, html and limited C, but I'm not a programmer.

Just an ordinary linux user, self taught using linux from 2000.
Regards.