BIOS hack to disable shared memory?

Video, SCSI, modem, CDROM/CDR/CDRW, etc.
Post Reply
Uranium235
BIOS Newbie
Posts: 28
Joined: Thu Jul 29, 2004 6:26 am
Location: Lancaster, PA

Wed Mar 28, 2007 5:36 pm

Hi

I've got an older Super7 board, a Powercolor P561A with integrated video and no AGP slot. The on-board video cannot be disabled. All I can do is set the shared video memory to 4MB. Is it possible to modify the BIOS to make 0 MB shared memory an option? I've looked at the BIOS with Modbin but there appears to be no hidden settings there. Any ideas?
cp
BIOS Guru
Posts: 1914
Joined: Mon Oct 21, 2002 9:07 pm
Location: Germany

Wed Mar 28, 2007 6:38 pm

just plug in a pci card and the onboard video will be disabled.
Uranium235
BIOS Newbie
Posts: 28
Joined: Thu Jul 29, 2004 6:26 am
Location: Lancaster, PA

Wed Mar 28, 2007 6:42 pm

I've done that but the shared memory is still being used. I'd like to disable the shared memory completely. I've tried leaving the first memory slot open but that doesn't work either. Windows sees both the PCI and onboard video as a dual display setup. Disabling the onboard video in the device manager makes the board really unstable. Also when I load the drivers for the PCI card the system locks up on reboot. The only thing that really works is the onboard video by itself.
edwin
The Hardware Archivist
Posts: 6227
Joined: Wed Mar 20, 2002 7:11 pm
Location: Netherlands
Contact:

Wed Mar 28, 2007 7:49 pm

Ah, the infamous Ali ArtX chipset. What OS are you using and how much internal memory? Did you ever run memtest86 on the memory?
edwin/evasive

Do not assume anything

System error, strike any user to continue...
Uranium235
BIOS Newbie
Posts: 28
Joined: Thu Jul 29, 2004 6:26 am
Location: Lancaster, PA

Wed Mar 28, 2007 8:16 pm

This is with Windows98SE. I use 512MB (2x256) of Crucial PC133. I have used Memtest which lead me to believe the shared memory is the source of the problem. The higher the shared memory selected, the more Memtest errors show up. Smaller amounts of shared memory result in fewest amount of errors.
edwin
The Hardware Archivist
Posts: 6227
Joined: Wed Mar 20, 2002 7:11 pm
Location: Netherlands
Contact:

Wed Mar 28, 2007 9:02 pm

Does it matter if you put only one stick in there or two? Tested them seperately?
edwin/evasive

Do not assume anything

System error, strike any user to continue...
Uranium235
BIOS Newbie
Posts: 28
Joined: Thu Jul 29, 2004 6:26 am
Location: Lancaster, PA

Wed Mar 28, 2007 11:04 pm

No change either way. Both these sticks tested good on this board and other boards. Seems the problem really happens when I try to use a PCI video card and it doesn't matter which one I use. I've tried a MX400, a Permedia 2 and an S3 Virge.
edwin
The Hardware Archivist
Posts: 6227
Joined: Wed Mar 20, 2002 7:11 pm
Location: Netherlands
Contact:

Fri Mar 30, 2007 12:31 pm

I think I have seen something about replacing the onboard video bios, maybe it's also possible to completely remove the video bios part. Not sure how the board would react though. I think the best option is to have an extra bios chip at hand and using that for flashing the modified bios. If it doesn't work you can simply put back the working one.
edwin/evasive

Do not assume anything

System error, strike any user to continue...
cp
BIOS Guru
Posts: 1914
Joined: Mon Oct 21, 2002 9:07 pm
Location: Germany

Fri Mar 30, 2007 4:45 pm

the size of the shared ram is defined by some northbridge register. since there's no datasheet available it's some kinda needle in a haystack :(
Uranium235
BIOS Newbie
Posts: 28
Joined: Thu Jul 29, 2004 6:26 am
Location: Lancaster, PA

Fri Mar 30, 2007 5:18 pm

I think I have seen something about replacing the onboard video bios, maybe it's also possible to completely remove the video bios part. Not sure how the board would react though. I think the best option is to have an extra bios chip at hand and using that for flashing the modified bios. If it doesn't work you can simply put back the working one.
Maybe that would be the best thing to do. It looks like the BIOS already defaults to the PCI slot for "Init Display First". I've got spare BIOS chips I could hotfash for recovery.
the size of the shared ram is defined by some northbridge register. since there's no datasheet available it's some kinda needle in a haystack :(
Yeah, I've run into that problem too, no datasheet.:( Would it be possible to find the correct register for shared memory by using Wpcredit and cycling through the shared memory options in the BIOS?
cp
BIOS Guru
Posts: 1914
Joined: Mon Oct 21, 2002 9:07 pm
Location: Germany

Fri Mar 30, 2007 9:09 pm

yep, that would be possible. as long as only one register gets altered..
Uranium235
BIOS Newbie
Posts: 28
Joined: Thu Jul 29, 2004 6:26 am
Location: Lancaster, PA

Mon Apr 16, 2007 5:10 am

OK, I finally had a look at Wpcredit using different shared memory settings, there are nine different registers that have shown changes. A needle in a haystack for certain....
I may be onto something, I was reading some release notes on the driver CD that came with this motherboard and there are problems noted with ACPI enabled. The BIOS defaults to ACPI enabled and that is what I was using. I'll try it out with ACPI disabled and see what happens.
edwin
The Hardware Archivist
Posts: 6227
Joined: Wed Mar 20, 2002 7:11 pm
Location: Netherlands
Contact:

Mon Apr 16, 2007 7:12 am

OK, thanks for your patience and feedback so far :)
We'll keep trying to dig up useable info.
edwin/evasive

Do not assume anything

System error, strike any user to continue...
indianoutlaw187
New visitors - please read the rules.
Posts: 6
Joined: Tue Jun 12, 2007 6:09 am

Tue Jun 12, 2007 6:23 am

what is the info on your northbridge? What kind is it? Might be able to help you find the register.

Also, does your board have an AGP/PCIExpress Video slot?

with PCI, the bios will enable both internal and external graphics, leaving the internal as secondary.
Post Reply