DVI versus Analog.......

[JRS]

Ok, just found out I can play Myst 3 and Half Life with my XP computer and
9800 Pro if I run the LCD monitor in Analog mode instead of using the DVI
connector. Using Cat 3.9's.

If I run in DVI mode, all I get is a black screen, it's like the monitor
can't display the 640x480 mode, but it does work fine in analog mode. Of
course then I lose the DVI digital crispness and clarity.....

Does anyone know if this would be a monitor issue, or an issue with the
ATI card or drivers not scaling properly in DVI mode?

JRS steinie**X**@pacbell.net
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[Ben Pope]

Ok, just found out I can play Myst 3 and Half Life with my XP computer and
9800 Pro if I run the LCD monitor in Analog mode instead of using the DVI
connector. Using Cat 3.9's.

Analog mode connected to the normal 15pin D-type monitor connector or the
DVI to 15 pin connector?

If I run in DVI mode, all I get is a black screen, it's like the monitor
can't display the 640x480 mode, but it does work fine in analog mode. Of
course then I lose the DVI digital crispness and clarity.....

Does anyone know if this would be a monitor issue, or an issue with the
ATI card or drivers not scaling properly in DVI mode?

In Display -> Settings -> Advanced -> Displays

Make sure your DVI connector is the primary display.

Ben

 

[JRS]

Connected to the normal 15pin connector..


When I had the DVI connected, it was the only display in the control
panel, the other 3 had red X's, only the FPD (flat Panel Display) was
active. I also used the newest Inf file from Viewsonic for the setup.

Just strange that it works fine in analog, but seems like it won't display
less than 800x600 when using the DVI connector.



JRS steinie**X**@pacbell.net
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[Barry Watzman]

The answer to this is actually kind of complex.

The monitor and video card communicate with each other over a "DDC
channel" (Display Data Channel, it's effectively a serial port that
takes 2 pins of the DVI connector). If they can't find a common mode
that they can both use, you don't get a picture. In most cases, if the
signal put out by the video card doesn't match a set of signal
parameters in a table in the firmware of the display, you don't get a
picture. There are LOTS of errors in various displays as to what they
can and can't accept, there are different "versions" of DDC, the whole
situation is kind of a mess. SOME of the ATI products have an option to
tell the monitor to "ignore DDC", and to display "all possible operating
modes" (vs. only modes believe to be supported by the monitor). You may
be able to get things working using those settings, but it's also
possible your particular LCD display actually can't display the
low-resolution format required by the game.

 

[JRS]

Thanx for all the info.

Still strange that it works in analog, so that means the monitor supports
it, or maybe the card is doing the scaling in analog?

In DVI mode, the lowest I could set it was 800x600 when playing around in
the control panel, lower than that, and it was a black screen, and I had
to wait for Windows to reset it since I didn't click the OK button in the
"can you read this" window......

I still wonder if it's the ATI card that doesn't support lower than
800x600 in DVI mode, or as you say, it's not communicating with my LCD
monitor properly in those modes.

Anyhow, thanx. Just gonna use the analog for now, that way I can at least
play these older games til I get tired of 'em again. All the newer games
I have seem to work fine with DVI.






JRS steinie**X**@pacbell.net
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[Barry Watzman]

It's not strange that it works in analog mode. The analog mode gets
converted to a digital mode by the monitor. The conversion is kind of
"sloppy" and if you have the right software, you can really see just how
bad it may be (you want a test pattern of vertical lines, one pixel
wide, alternating black and white). But while it's sloppy, the analog
mode will actually allow a wider variety of modes than the digital [DVI]
modes. For DVI, you either get an exact match or no picture at all.
The very sloppiness of the analog mode also makes it a bit more flexible
and tolerant of video card to monitor mismatches.

DVI mode SHOULD support VESA standard 640x480. But this wouldn't be the
first case where it didn't. The problem may either be in the monitor or
the video card.

 

[John]

You'll never tire of HalfLife

Thanx for all the info.

Still strange that it works in analog, so that means the monitor supports
it, or maybe the card is doing the scaling in analog?

In DVI mode, the lowest I could set it was 800x600 when playing around in
the control panel, lower than that, and it was a black screen, and I had
to wait for Windows to reset it since I didn't click the OK button in the
"can you read this" window......

I still wonder if it's the ATI card that doesn't support lower than
800x600 in DVI mode, or as you say, it's not communicating with my LCD
monitor properly in those modes.

Anyhow, thanx. Just gonna use the analog for now, that way I can at least
play these older games til I get tired of 'em again. All the newer games
I have seem to work fine with DVI.







JRS steinie**X**@pacbell.net
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<--Of all the things I've lost, I miss my mind the most-->

 

[GSeals]

I've got the same issue with an AIW 9800 PRo and a Viewsonic VG 191
LCD monitor with Windows XP. Boots ok, most windows apps run fine,
but games result in a black screen when connected via the DVI input.
I can hear the audio, but no display. I've tried various CAT versions
and have gone back to 3.7 for now. I have set the games to various
higher resolutions while in analog, then switched to the DVI
connection and still get the black screens. I dont think it's related
to the resolution. Like JRS, I have no problems when using the
analog connection. I connected the monitor to an older computer with
an AIW 8500 DV card and everything works, in various resolutions,
when using the DVI connection, so my particular issue is with the 9800
Pro card. Barry's answer seems to make the most sense to me. I just
wish there was a workaround for us to use the DVI connector.

GSeals

 

[paminof]

I too was getting a blank screen intermittently. I fixed the problem
by setting the refresh rate to 70, i.e, from the default 1280x1024 @60
Hz. to 1280x1024 @70 Hz. Display properties > Monitor settings > Set
refresh frequency to 70 Hertz.

I have a Powercolor ATI Radeon 7000 with a ViewSonic VP181 monitor in
DVI-D mode. For some reason the ATI 7000 intermittently produces
frequencies that are out-of-spec for this monitor, i.e. ~59.5 to ~60.5
instead of exactly 60 Hz. The ViewSonic VP181 goes blank when it
receives an out-of-range signal. My Radeon 7000 seems to be delivering
a more consistent refresh frequency when set to 70 Hertz. I don't know
why, but the black screen problem is now gone.