ATI AIW 7500 with digital display (DVI)

[LRM00]

I added a ATI All-In-Wonder Radeon 7500 to my system (Soyo-K7V Dragon Plus motherboard). I connected a LCD monitor with DVI. All works well, except for the following. When I start the PC I no longer see the POST/BIOS messages, and related to that: if I start with a floppy (e.g. Windows 98 startup diskette) I see nothing, and in Win 2000, Win XP and Win 98 I no longer see the first part during startup (e.g. logo screen etc), I see a blank screen until the "logon with Ctrl-Alt-Del" message.

When I connect the LCD with the VGA connecter, all works as before.

Is there any way to see the startup messages on the DVI connected monitor?

 

[Peter]

This happens with DVI if the panel itself doesn't list a DOS text mode in its DVI plug'n'play data (the "EDID" information).

You know, on a VGA plug, the display unit must cope with what the computer feeds into it. With DVI, it's reversed - the graphics card produces exactly the timing requested by the DVI display unit. If the display's own list of supported resolutions and required timings does not include a text mode, then you get the solar powered flashlight effect.

regards, Peter

 

[NuovoTech]

Peter - Any way 2 find this out ahead of time(ie from spec sheets)? Are many LCDs set up this way? Seems a hassle 2 switch 2 a VGA cord just to tweak BIOS, etc!

 

[NuovoTech]

LRM000 - Follow this Google thread. It appears this problem DOES exist with Radeon 7500/8500 vid cards using DVI out...UR not alone! ATi replied it may require a new BIOS for your Radeon.

BTW I'm following this cause I'm thinkin of purchasing a AIW Radeon 7500 & a Samsung 191T LCD running W98. If I can not access DOS/POST screens with DVI this will affect my plans. It appears other brands of vid cards do not have this problem...

 

[Peter]

Good point, it might of course also be the VGA card's BIOS that's not adjusting its output to a resolution the display unit supports.

I've seen it go wrong on both ends - DVI panels with buggy EDID information, and VGA BIOSes that didn't do it right.

The best way to read a display's DDC or EDID data is to connect it to a Linux box and have a look at the XFree86 startup log. There's a readable report of all the stuff in there.

regards, Peter

 

[NuovoTech]

Peter - If ya have the time follow that link(U have 2 backtrack a bit 2C all 22 messages) in my last post & LMK what U think about it. TIA!

 

[LRM00]

Thanks for your responses. After reading the link provided above and doing some related Google searches I found that Radeon 7500 and 8500 owners have similar problems with different TFT's.
It is probably caused by a sync problem (I do see a flash of a startup screen at the beginning, others report a mispositioned startup screen). The Planar has a 60 Hz refresh rate in digital mode, the Radeons assume and use 70 Hz before the driver kicks in. After that, inside Windows, they use 60 Hz (from display setup) and the image is very nice, I have to give them credit for that.
ATI is aware of this problem, and reported in March that their engineers are working on it. Hopefully we will get a BIOS update to fix this problem.
In the mean time: BEWARE. It does not bother me too much (I can use the VGA cable to make changes in the motherboard setup, and I bought a retail box so I did not spend extra $$ on a DVI cable), but it is still annoying. Linux consoles and DOS boots have the same problems.