i have a really weird problem here...i seem to have a 'shimmering' console display when in 1024x768 framebugger mode, its really making my eyes bad now lol. its odd because it doesnt always do it, usually after a reboot it will do it, but on normal startup usually wont (but sometimes will?!). ive tried reinstalling the kernel and modules etc from the slackware cd, but it happens literally immediatyl after LILO. have tried different resolutions in LILO and 800x600 works ok...so i checked and 1024x768 works fine in windows XP, so doesnt seem to be the card or display.

it looks like the display does when something probes it...any ideas? would be really aprreciated! thanks

Guess you don't like the 64Hz refresh rate ;)

I'd suggest to try an configure your X to match
your hardware ... what graphics chipset are
you using?


Cheers,
Tink

i dont have x :P decided to try a very bare system to sort of force me to use the CLI, otherwise id just use KDE when i could to do things, this way i have no other option...and its proving good! i finally found out the problem (i think), id removed the package 'seejpeg', which had SVGA libs in it according to the package text. What gets me is why could it display 800x600 fine?? kindof off, but i reinstalled seejpeg and on 2 reboots both times were fine....so fingers crossed!

thanks for the help though

this is weird! my console was fine for 2 days with lots of restarts, and no for no reason whatsoever (no hardware changes, module changes, software or anything (well unless u class messing with mutt as 'changes' :P)) i havent even logged in as root so im pretty sure nothings changed...yet its shimmering again!

i tried ALL refresh modes available to me in windows (60, 70, 72 & 75hz) and they are all fine, the monitors OSD identifies the modes correct each time, i havent checked what hz it reports in the linux console but i will do.

it still seems like something probed the video card, u know what i mean? when something probes a vid card to autodetect it it shimmers....looks like that

any help? this is driving me nuts, slack has always worked fine b4, though ive never used it this heavily in the console only, to reiterate i have no x or anything like that

on a side note, is it possible to remove the penguin in the 1024x768 framebuffer console?

cheers!

-----------------------------------------------

ok well...i just logged in and am now typing this into links as we speak and my console is fine??? its perfectly normal and now im even more confused. reckon that could have anything to do with the fact i went into windows then back into slack?

if its any help the res and refresh are 1024x768@59hz, which is perfectly within tolerence (obviously as its fine now) and i cant see its the cards fault as it works fine in windows and most of the time in slack

any ideas? thanks a hellof lot

ok new post now...i was a little quick to judge on the last post and on closer inspection there WAS a slight shimmering...which i *think* (though might just be my eyes) got worse over time, im now in 800x600@60hz which is perfect (ive sat here staring at it for 5 mins!). so the golden question...what the hell? lol

no-one know??

It's still a refresh-rate problem ... you could
have shown some initiative and looked through
your kernels Documentation ....

It took me ~ 1 minute to locate the relevant
info :P


Cheers,
Tink

yeh alright no need to be like that, fyi i *have* looked through what i thought relevant but i dont think this is a refresh problem, ive seen what that looks like and this simply doesnt look like one, it does it some of the time but not others yet the refresh rate is constant so why would it sometimes be bad and sometimes fine? also...60hz has always worked fine so why would linux show any problems? plus...when i did a full install of slack i didnt have this problem yet i was using the 1024x768 framebuffer mode then so it makes no sense it should do it now.

i dont want to sound aggresive but i have actually tried what i can think of. its not like im using this forum as a first resort...ive been through all the man pages for lilo to check see if i can find a way to change the refresh rate and no joy, the last i want to do is get annoyed at you if your tryin to help but its not like im sittin on my arse and just firing dumb questions at you that i havent tried to solve myself.

This is a little long. Before I begin, I want to mention that I found this thread because I was searching slackware boot issues, and happened to think I could shed light on this particular thread. By no means was I just looking for issues to answer, but when I run into a thread like this, I contribute when I can. This is why there is so much stress placed on putting in as many specific details as possible (more on details later).

The "shimmer" that you speak of is typically an issue with low refresh rates - even though you think it isn't - so don't yell at those who are pointing out what seems obvious... myself included.

You very well may already know this, but I'm gonna say it anyway, as this may help someone else doing a search, and not necessarily just you (which is something else you should keep in mind before sounding aggressive)...

Simplified definition of a "refresh" problem: Hz is cycles per second. Indoor electric lighting is actually a 60Hz (US, 50Hz in many countries) strobe (flashing or blinking). If your refresh rate is not significantly higher than the strobe rate of your indoor lighting, the image may appear to bounce. Under natural light, this should not be noticable at all (assuming you normally do not notice the strobe effect of indoor lighting). The bouncing image is percieved when you get a conflict in the timing of the lights surrounding the computer and the current refresh of the area of the screen you are looking at.

That said, it is possible in my mind (being I'm not at your computer) that the problem coming and going could be changes in the lighting surrounding the computer. This could be clouds going overhead, others in the household turning lights on and off, etc.

This is a test to do... Turn off all electrical lights in the area where your computer is set up. If you need lights at all, use a candle, or the sun. Do you have a "shimmer"? Watch really carefully. Turn on some incandecent (standard screw-in light bulb) or flourescent lights, turn off any candles and/or shutter your windows - do you see the "shimmer"?

As for the non-issue in Windows, an apples-to-apples comparison to run would be to check Windows again, except bring up a COMMAND PROMPT (or MS-DOS Prompt) and full screen it. This will give you the same (close enough) white/grey text on black background comparison, as the problem may not be pronounced with full graphics filling your windows screen.

Another strangely common reason for a shimmer effect is having speakers too close to your monitor.

Now, if under natural light, you are still getting this "shimmer" issue, then look for another solution. Start by following the advice in post #2 - let us know the exact video solution (Graphics Chipset) you are using. That way someone with your same video card may find this thread through a search (thus the forward reference at the beginning).

Also... (and I may not be right on this one)... but I recall seeing an IMAGE selection in the Kernel compile menu, so I think the Penguin is replaceable (if not removable) during kernel config.

ok, just to straighten things out slighty..under normal circumstances i do not shout or become anything other than amiable with anyone, especially people offering me help and advice, it is simply that i dislike people assuming ive taken no steps to fix the problem myself as i have done, i do not use this forum as a first source to resolve my problems. first of all i will look in any man pages i can find related to the topic, also the documentation sections where possible but i hope people understand how overwhelming the amount of documentation there is in linux for someone who is new to it, it is not blaringly obvious where to look 100% of the time and i may miss things, telling me how easy it is to find an answer isnt helping. i understad that 99% of the time i could fix these problems myself given an accute ability to search through manual pages and documentation but i do have that ability, when looking at some documents my eyes can glaze over with the amount of technical information which i simply do not understand.

as for the problem, thankyou for your help. i have tried as you advised and funnily enough my console is fine, i wont take this as an end to the issue though as this has happened before (working for a while for what seems like no reason, then reverting back to its old state). i have done as you asked (which was fine), afterward i reverted everything back to normal (lights etc) and the problem still is not present at the moment.

As for the advice in post 2, i have had that problem before with redhat and xvidtune helped the matter (on another machine though), but at the moement i am running without X. I have just the command line and a minimal system.

My video card is an ATI Radeon 8500. If the problem happens again I'll post any info i can think that is relevant, though you may have to excuse me as I am not positive exactly what info *is* relevant.

i appear to have found the problem, though i had already tried this once, it seems to have worked now. i entered my monitors OSD and changed the clock and phase, which seemed to help. some of the console appears blurry on occasions but mainly fine. thanks for all the help anyway!

Once you have learned the "starwars" xscreensaver sdrawkcab - then you can bash the tink.

This could be totally bunk, but have you checked out your video card fan (do you have one?)?? Sometimes they get clogged up w/ lint/dust and it can cause otherwise inexplicable problems???