spare-flair wrote:

Any ideas? Wild guesses? Conspiracy theories???
Thanks!

Snow Crash! 😁

Actually, this is what happens when an LCD screen on a laptop loses sync - or at least one of the things that can happen. Somehow, DOSBox is sending your screen into a resolution/refresh rate combo that is unsupported by your video chipset and screen. If you can attach an external monitor that displays mode info when brought up in an on-screen menu, you can find out what resolution/refresh rate combo it's going into - and then amend your settings accordingly. This is not a flaw of DOSBox but of your video card and screen.

Newbie alert!!!! I have - for the first time - tried with fullfixed/width/height parameters, so I could very well be totally out in the woods here, but...

Have you tried something like this:

1[sdl]
2fullfixed=true
3fullwidth=1024
4fullheight=768
5output=surface

in the dosbox.conf file?

Check you normal display resolution (1024x786, 1280x1024, or whatever), and use them. Then try lowering to say 800x600, 640x400 and see if your LCD screen will accept those settings.
--
MiniMax

Hey, thanks a lot for this suggestion. I had a feeling it might have been the refresh rate or something to that extent. The frustrating thing about this laptop is that it provides no monitor information or drivers. All it gives me is "plug&play monitor' and the tech-support line is automated and doesn't give me any info on the type of display they use.

I'll hookup my desktop LCD into the VGA out and see what value it returns.
A very strange thing is that in the ATi display settings, I can set the refresh rate to whatever I want it to but the settings have no affect on the display. I set it to 200hz once and there was no change. I really have to get a real person on the line (generic laptop, bad tech-support and no technical documentation, much less a manual included).

Where would you suggest I change settings once I do figure out what refresh rate DOSbox is trying to get my hardware to goto? Thanks for telling me what it's called anyway (Snow Crash). Can it be done through the DOSBox config file? Because obviously the display drivers in my laptop (ridiculous that ATi doesn't provide any drivers because they are proprietary to manufacturers and I have to use the antiquated one on the driver disk they sent me) aren't properly making use of this display. The only thing I'm sure of is my native resolution is 1024x768.

Okay, this snow crash thing is very irritating.
The LCD display is running at 48.3kHz (what does this number denote?) at 60Hz refresh rate and 1024x768 resolution.

When I connect a monitor to the VGA out and shut off my laptop's display, the monitor claims that DOSBox forces the display to 31.6kHz (again, what is this number?) at the usual 60Hz refresh rate but the resolution is 640x480! I believe my laptop cannot handle a 640x480 resolution because it doesn't appear in the display properties. Can I force DOSBox to perform fullscreen at 800x600 or 1024x768???

Strange thing is that when I clone the displays, and run DOSBox to fullscreen, the monitor claims its still in the original 48.3kHZ, 60Hz, 1024x768 setting and it works perfectly, but the laptop LCD snow crashes. If I exit back to desktop from the monitor and then switch back to the laptop LCD, it resets to the desktop.

Can anybody help me?

Minimax, you are probably right, I don't know why I didn't see your post I'll try what you suggested to force the DOSBox resolution. All I can tell is that my laptop is very fickle about 640x480 and will snowcrash 90% of the time.

-EDIT-

I've tried out all the settings in the conf file and for now, the only one that doesn't result in a snowcrash or video anomalies is to use overlay instead of surface mode. Both OpenGLs snowcrash at the wrong resolution and give me a lot of desktop blitter on the top and bottom of the screen, not to mention it retards system performance a lot.

The only problem with overlay mode is it isn't the best looking and it results in a widescreen effect at 1024x768 with the top and bottom of the screen cropped. I've tried adjusting the vertical resolution but this results in the fullscreen being completely off-center.

I can live with this to play laptop games, although I would prefer a fullscreen mode that actually uses the entire display and is crisper than overlay mode. Thanks anyway. As usual, any suggestions?

This is the only configuration that works acceptably for me. Most of the rest snowcrash or mess up the display. 🙁

1fullscreen=false
2fulldouble=false
3fullfixed=true
4fullwidth=1024
5fullheight=768
6output=overlay
7hwscale=1.00[/code

spare-flair wrote:

Okay, this snow crash thing is very irritating.
The LCD display is running at 48.3kHz (what does this number denote?) at 60Hz refresh rate and 1024x768 resolution.

60 Hz x 1024 x 768 = 47.185.920 Hz =~ 47.2 kHz =~ 48.3 kHz.

Guess there is a few hidden/overshot scanlines that need to be added somewhere...

spare-flair wrote:

When I connect a monitor to the VGA out and shut off my laptop's display, the monitor claims that DOSBox forces the display to 31.6kHz (again, what is this number?) at the usual 60Hz refresh rate but the resolution is 640x480!

60 Hz x 640 x 480 = 18.432.000 Hz =~ 18.4 kHz != 31.6 kHz.

Something is wrong here - could this be why your display is crapping out? If it somehow is trying to drive it at 100 Hz then it almost matches: 30.7 kHz (remeber to add those missing Hz from the earlier example...).

Can you reproduce the snowflakes if you manually change your resolution to 640x480 and ups the refresh rate to 100 Hz?
--
MiniMax - "After all, I own a computer"

MiniMax wrote:

60 Hz x 1024 x 768 = 47.185.920 Hz =~ 47.2 kHz =~ 48.3 kHz. […]
Show full quote

spare-flair wrote:

Okay, this snow crash thing is very irritating.
The LCD display is running at 48.3kHz (what does this number denote?) at 60Hz refresh rate and 1024x768 resolution.

60 Hz x 1024 x 768 = 47.185.920 Hz =~ 47.2 kHz =~ 48.3 kHz.

Guess there is a few hidden/overshot scanlines that need to be added somewhere...

spare-flair wrote:

When I connect a monitor to the VGA out and shut off my laptop's display, the monitor claims that DOSBox forces the display to 31.6kHz (again, what is this number?) at the usual 60Hz refresh rate but the resolution is 640x480!

60 Hz x 640 x 480 = 18.432.000 Hz =~ 18.4 kHz != 31.6 kHz.

Something is wrong here - could this be why your display is crapping out? If it somehow is trying to drive it at 100 Hz then it almost matches: 30.7 kHz (remeber to add those missing Hz from the earlier example...).

Can you reproduce the snowflakes if you manually change your resolution to 640x480 and ups the refresh rate to 100 Hz?
--
MiniMax - "After all, I own a computer"

You are partly right, but mostly wrong. There are hidden scanlines at the top and bottom of a display which you can see if you adjust it. You don't however, get horizontal frequency, 31.6kHz for a standard 640 x 480 display the way you calculated. 31.6kHz is the number of times a monitor draws a line, 60Hz is the number of times the monitor redraws the display, called vertical refresh. If you divide horizontal by vertical you get lines drawn per field so 31.6kHz / 60 Hz = 527 (rounded up). This is more than 480 true, but it's supposed to be. 60Hz x 640 x480 = 18432000 would be 18.4 MHz not kHz . Also, 48.3kHz is 1024 x 768 at 60Hz.

As for spare-flair's original question, do you have the most up to date display drivers for your laptop. That's all I can think of since about everything else has been covered.

Thanks KingDuff, I owe you a beer!

I might own a computer, but appearently I can not get the units right!

Well let's explain it a bit more than, since it's really 523 lines, considering 480 of those are displayed graphics, some are blanked lines which you'd see the blanking/border color and there's some lines that aren't draw but during those lines there's the vertical refresh. So then you have 800*523*60=25mhz and that happens to the vga clock. And in case you wondering where the 800 came from that's amount of clocks it takes for 1 horizontal line to be drawn together with again blanking and the horizontal sync.

I think you should figure out which drivers you should use for your lcd in some way.
I have experienced problems myself using the plug&play driver