DirectDraw interlace screenmode switching on Win 7

[Dr.Venom]

Hi Calamity,

Important update. I just noticed that AMD has updated the legacy driver to version 13.1 just yesterday, in which Windows 8 support has now been incorporated in the same driver! So it's one driver with Windows 7 and 8 support for the legacy cards.

http://support.amd.com/us/gpudownload/windows/legacy/Pages/legacy-radeonaiw-vista64.aspx.

This changes things of course re the 12.6 legacy driver. *If* you were to decide to hack the legacy driver then this 13.1 version would of course be the preferred version.

Would the hack of this driver add 120 modelines support for both Windows 7 and Windows 8? Or would you still have to do two separate hacks?  (I.e. would there be no benefit of having both Windows 7 and 8 support unified in the same video driver?)

The proposition would be quite cool:

GM supports all current releases of the Windows Operating Systems: Windows XP,  Windows 7 and Windows 8. Features:
- Dynamic resolution switching on all platforms
- Enlarged set of custom resolutions (120+) on all platforms
- Support for switching between both progressive and interlace modes on all platforms, both for DirectDraw and Direct3D.
- Unlimited dynamic 'on the fly' refresh rate changes for Windows XP . The feature has notable limitations on Windows 7 and 8: 'on the fly' changes can be done only once for each resolution during a session.
- Support for Magic Resolutions on Windows XP: all thinkable resolutions available by only installing 16 different "magic resolutions". Note: Magic Resolutions are not supported on Windows 7 and 8.
- Support for systems with dual video cards / monitor set-ups.  (Verified on Windows 7, to be confirmed for W8 and XP).

Disclaimer: for the use of GM on Windows a video card  *up to* HD 4000 can be used. This is due to limitations in HD5000+ video cards.

How about that sales pitch?  (I think I may be getting carried away a bit too much now... )

But seriously I would be excited about the full support for both Windows 7 and 8 with above features. I guess given where you are with GM, the only thing standing in its way would be a hack of the 13.1 legacy driver (no pressure! ).

How would you feel about this, given the things we have been discussing and testing in the past weeks?

[Calamity]

Hi Dr.Venom,

I have spent a good amount of hours these days trying to get something useful out of my HD 6450 & Cat 12.4, and finally I've given up. I thought there was possibly some hidden registry key that might redirect these cards into the path of virtue but all efforts were futile. The fact that these cards work perfectly under Linux means that it's just a software matter, so it's virtually possible to fix this situation by a clever hack of the Windows drivers, but reversing the Catalyst monster to this extent is definitely beyond my capacities.

Basically the new AMD cards won't work with arcade monitors because when they don't "feel" the monitor they enter a sort of dumb mode as soon as the drivers are loaded. So you can see the boot fine but once in Windows you're stuck with a 4-bit colors mode. No matter what you try you can't change the video mode.

On the other hand, if you plug a CRT with a valid EDID, the card works fine, but our custom modelines are completely overridden by some uncertain refactored modes that have nothing to do with the user defined timings. The modelines are certainly read and checked, because the refresh rates are taken into account, but they're rounded and recalculated to meet the monitor's capabilities, so a 15kHz mode will become 31 kHz. The worst part is that many resolutions, especially the low ones, are hardware stretched!!!, no pixel-perfect any more. A colossal load of ---steaming pile of meadow muffin---.

After booting with a PC CRT I can switch the cable to my arcade monitor (tri-sync) and so the dumb mode is avoided and I can switch resolutions on the arcade monitor. Anyway no 15 kHz is possible as the driver is still contaminated by the previous EDID information.

I believe it's not only the lack of EDID what makes these cards enter dumb mode, it has more to do with not detecting the arcade monitor (no 75 ohm load): http://soerennielsen.dk/mod/VGAdummy/index_en.php

Anyway, this was just to confirm that unless a miracle happens, under Windows, we're going to be stuck with the HD 4000 series for CRT support. So I'll try to focus on providing modded driver support for these cards on W7. I'm not sure yet if it will work at all. For economy, I'm just going to work with 64-bit drivers. I'll probably try with two versions, 13.1 and 9.3. The 9.3 is just to check if dynamic modelines ever worked under Windows 7. If I had to choose between dynamic modelines support vs want latest version my answer is obvious, but at least the user will have the possibility to choose.
 

[Dr.Venom]

Hi Calamity,

It's really too bad that the newer Radeon cards don't work at all with custom CRT modelines. Quite frustrating even when knowing that in Linux they work perfectly. It really seems that a lot of "safety" measures have been built into these newer cards/drivers on Windows are there to prevent at any cost that the user would be presented with a non-displayable screen. Probably useful for Ordinary Joe and Plain Jane, but it's definitely a colossal load of SPOMM from an emulators point of view .

I believe it's not only the lack of EDID what makes these cards enter dumb mode, it has more to do with not detecting the arcade monitor (no 75 ohm load): http://soerennielsen.dk/mod/VGAdummy/index_en.php

Those are interesting findings. From a positive point of view that leaves a *tiny* spark of hope, that possibly the combined effort of a hardware dongle, combined with a hack of the drivers would be able to make these higher end cards work with custom modelines. But I guess the amount of time and energy that would be needed for finding out, make it an undertaking that's probably only worthwhile if there were no other options/fallback at all.

Anyway, this was just to confirm that unless a miracle happens, under Windows, we're going to be stuck with the HD 4000 series for CRT support. So I'll try to focus on providing modded driver support for these cards on W7. I'm not sure yet if it will work at all. For economy, I'm just going to work with 64-bit drivers. I'll probably try with two versions, 13.1 and 9.3. The 9.3 is just to check if dynamic modelines ever worked under Windows 7. If I had to choose between dynamic modelines support vs want latest version my answer is obvious, but at least the user will have the possibility to choose.

This is *great* news. Thank you for investigating! Hopefully it will work out well...