Well, well, well. Isn't That Interesting.
*goes and HEX edits his VGA.SYS*

Amazing.

Let's get the ball rolling on this!!

(I still think this will not fix LFB support - but it should help NVIDIA and NOLFB combinations. 😀)

Comments people?

Snover wrote:

Well, well, well. Isn't That Interesting.
*goes and HEX edits his VGA.SYS*

Well, well, Windows file protection jumps in and restores the original file. I guess we have to either disable WFP (not an easy task, afaik) or pack a patched vga.sys file in a way similar to a hotfix, so it will be accepted as an upgrade.

Plan B: look at the source code in VDMSound and patch vga.sys in memory. Quite a task, since it's been 5 years since I last wrote something to run on ring 0.

Regards,

MajorGrubert wrote:

I guess we have to either disable WFP (not an easy task, afaik)

Piece of cake 😀

Windows has a backup copy of it's crucial files. when you alter something in the windows/system32 folder, it's automatically replaced with the backup. Microsoft has been nice enough to let the backups as is in another folder, and these files are not protected by anything 😀. \WINDOWS\ServicePackFiles\i386 if you have the SP1 installed, and another folder (I don't remember which) if you haven't.

Search for VGA.sys in your windows subfolders. Rename all the vga.sys you find but the one in system32\drivers to let's say VGA.syso, you'll be able to patch the "good" VGA.sys.

Another option: you can edit the backup version, then modify the "protected" one, and let windows copy the patched file for you :p

So how much extra functionality (on a system with an nVidia card for example) would this hack give me?

The memory patching thing sounds like the best way to go, as it doesn't require modification of critical system files (as botched as they may be).

vlad: if you decide to implement a memory patcher, please please PLEASE consider keeping it separate from the full-screen (i.e. "basic VESA support") checkbox/option in LaunchPad/VDMsound! It is entirely possible that one would want to use one option without the other. Just putting in my two cents 😉

I could've sworn that killing Windows file protection was as simple as editing a registry key...hmm...

Originally posted by Zorbid \WINDOWS\ServicePackFiles\i386 if you have the SP1 installed, and another folder (I don't remember which) if you haven't.

That would be WINDOWS\system32\dllcache\vga.sys, at least for XP.

I knew it wouldn't be this easy. DOS titles or any command prompt attempting to "full-screen" generates this error:

Hmmm, Wonder what vid card this guy had.

Oh, I also wish I could do stuff like that.....I feel like Rip Van Winkle. The only diff is that I've been awake and I'm still falling behind. 🙁

Nicht.

W I N D O W S E X P E E .

Snover wrote:

I could've sworn that killing Windows file protection was as simple as editing a registry key...hmm...

According to MS knowledge base article 222473 (http://support.microsoft.com/default.aspx?sci … kb;en-us;222473):

All registry settings for Windows File Protection/System File Checker are located in the following registry key: HKEY_LOCAL_MAC […]
Show full quote

All registry settings for Windows File Protection/System File Checker are located in the following registry key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon

(...)

Registry Values
SFCDisable (REG_DWORD)
0 = enabled (default)
1 = disabled, prompt at boot to re-enable
2 = disabled at next boot only, no prompt to re-enable
4 = enabled, with popups disabled

NOTE: For options 1 and 2: Both of these options require a kernel debugger to be hooked up for those options to become useable. If a kernel debugger is not hooked up, Windows File Protection is not disabled.

So it's simple only if you have a debug build of the kernel.

Regards,

Nicht Sehr Gut wrote:

I knew it wouldn't be this easy. DOS titles or any command prompt attempting to "full-screen" generates this error:

I booted my Windows 98 copy and edited the copies of vga.sys from %systemroot%\system32\drivers and %systemroot%\system32\dllcache (the only ones I found in my Windows 2000 partition). Rebooted into Windows 2000 and got a beautiful BSOD: STOP 0xc000026c Unable to load device driver vga.sys.

Vga.sys has an .exe file header (with MZ and PE signatures), so I guess that patching the file would invalidate the checksum in the header. Does anyone knows how to fix this?

Regards,

Booting into another OS is unecessary...if your fast enough to copy the files around while in the OS. 😉

DosFreak wrote:

Booting into another OS is unecessary...if your fast enough to copy the files around while in the OS. 😉

Yeah, but I need to reboot in order to load the modified vga.sys and it gives me the same blue screen upon reboot.

Did someone got this working on Windows 2000? Maybe I'm doing something really stupid 😕

Thanks,

Snover wrote:

I could've sworn that killing Windows file protection was as simple as editing a registry key...hmm...

It was. Then they released the service packs and you found yourself having to hexedit the relevant files. VP.net has a summary of the relevant info here.

Major Grubert, correct me if I'm wrong, but we are talking about VESA in Windows XP and hacking/editing the Windows XP vga.sys.
What makes you think the same applies to W2k?

Well if he found the same byte string in his vga.sys, then I'll wager that it's (almost?) identical to the one in XP. I edited a copy of mine, but I'm waiting to hear reports of what I can hope to gain from it before I go kludging up my OS.

Dominus wrote:

Major Grubert, correct me if I'm wrong, but we are talking about VESA in Windows XP and hacking/editing the Windows XP vga.sys.
What makes you think the same applies to W2k?

Since VESA support in Windows 2000 have mostly the same limitations as in Windows XP and the vga.sys driver is very similar, I decided to try the same patch on Windows 2000. By the way, the limits imposed to VESA modes by vga.sys under Windows 2000 are different from card to card, just as they are under Windows XP, but the causes are the same: vga.sys traps several I/O instructions issued by the BIOS and prevents some mode changes.

HunterZ wrote:

Well if he found the same byte string in his vga.sys, then I'll wager that it's (almost?) identical to the one in XP

That's correct, the same 32 byte sequence appears in the Windows 2000 version of vga.sys.

Regards,

Originally posted by DosFreak Oh, I also wish I could do stuff like that.....I feel like Rip Van Winkle.

?? You mean tracking down the tiny details, right. Don't tell me Mr.Network Admin isn't comfortable with a hex editor.

Originally posted by Snover Nicht.

W I N D O W S E X P E E .

*blink*
*blink*

Ok, I'm sure that makes sense to someone.

Originally posted by DosFreak Booting into another OS is unecessary...if your fast enough to copy the files around while in the OS.

True, I edited both of my VGA.SYS files while still in XP (kind of like swapping out wiper blades on my car while flying down the highway...but without all the wind).

The backup took fine, so did the active version. But two seconds after I saved the active SYS file, I received a prompt demanding my XP CD. I refused and it gave me dire warnings, but accepted my decision.

Put the original back after I realized it killed all full-screen modes.