Solved

What does VGASAVE do? (More enclosed)

Posted on 1997-07-23
18
796 Views
Last Modified: 2013-12-28
I am working with some proprietary pieces of hardware in NT 4.0 Workstation, and I need part of the B0000 range in order for my hardware to operate properly.  When I configure the card to the B0000 range, the event log tells me I am having a memory address conflict with VGASAVE.   According to the NT Diags, VGASAVE resides at A0000-BFFFF and I cannot figure out how to change that address to something available.   In my current configuration, I have disabled VGASAVE completely, and my hardware/software applications work properly.  The only concern is if this will cause an unseen problem, or if it's just a matter of time before it crashes something in NT.   This configuration will be used on a large scale and will be under heavy scrutiny, so I need to make sure that I know my stuff before it's released.   I've searched many many resources and have found nothing that explains its purpose.  So again, I ask what does VGASAVE do, and is it safe to disable it?

0
Comment
Question by:digiscrae
  • 7
  • 5
  • 2
  • +2
18 Comments
 
LVL 5

Expert Comment

by:cer
ID: 1780354
A0000-Bffff is the video display memory range. Grafics is from A0000-Affff and VGA-textmode from b0000-b7fff rest is for Hercules monochrome adapter.
Don't really know what VGAsave does, if it protects the space against other programs or if it just "saves" this area to be able to rebuild it after displaychanges.
Do you have problems with fullscreen DOS-boxes with text/grafic inside?

0
 
LVL 5

Expert Comment

by:cer
ID: 1780355
There is a VGASAVE under DOS, it is a screen capture program.
I have no VGASAVE running (in taskmanager), where do you see it?
Maybe you installed it accidentally ?
It seems it is due to some DOS compatibility.
I belive if you remove it you may get a garbled screen, but most likely it will run OK.

0
 

Author Comment

by:digiscrae
ID: 1780356
It's not something that is loaded in the Taskmanager.   It seems to be a device that is loaded.  I have not been able to locate it in NT Server, but in Workstation it's under    Control Panel ->  Devices.   Scroll down and take a look at the H/W Profile for it.    
  I will try going to full-screen DOS mode this morning and I will post back.    My application doesn't require using command mode so I may be in luck.    

Thanks --  Will post an update later.
0
 
LVL 5

Expert Comment

by:cer
ID: 1780357
This morning? for me its evening :-))
I will have an additional look in MSDN today.
0
 

Author Comment

by:digiscrae
ID: 1780358
...Back to the drawing board...    I did find that a few of the initialization files for one of the proprietary pieces of hardware does require two DOS windows.   I did run a burn in with VGASAVE disabled and things seemed to work out okay.  I would appreciate if you could find any additional information regarding this and perhaps quotable text for my boss who doesn't believe it til he sees it.  ;)      

One thing that did happen:   When you have a DOS window up, and you try CTRL-ENTER to go to full-screen it gives you an error telling you that your Display Adapter is not available for this mode.   I thought that was considerate of Microsoft...  ;)

 If you could cut'n'paste any additional information, it would be appreciated.   I've upped the point value on this one, cause you balied me out on a deadline!      Put your next response as an answer so you can get what is coming...   Thanks again

0
 
LVL 2

Expert Comment

by:eizens
ID: 1780359
Reject if not satisfied...
      As I understand, and it is also what I was able to find, vgasave is the simpliest and the most stable video driver. If you look in Microsoft Technet, it is loaded in to groupes -- video and save video. I believe, that is really needed for you only if you want to restart in VGA save mode, because in this case it's only video driver loaded and if it's desabled you will stay without video. But I think that in save mode you can decise not to load your proprietary software, because it's only for diagnostics.
I think that you can desable loading of this device making changes in the registry.
Printable text you can find in MS Technet, running query VGASAVE.
Of cause, as usually, Microsoft documentation is long and without contant.


0
 
LVL 2

Expert Comment

by:eizens
ID: 1780360
 And one comment more. Of cause, this driver normally seems anneeded, because if you use modern adapter, you use hardware specific driver. The only case, when this driver is used -- when you restart in VGA video mode.
0
 
LVL 5

Expert Comment

by:cer
ID: 1780361
Yes, maybe that it is a "save VGA" driver. However, as i assumed you have problems in fullscreen (=fullscreen not possible).

Where is this "Technet" ?
I use http://www.microsoft.com/search/default.asp  to search in microsoft, but there were only 2 entries, where I was not allowed to connect.

0
 
LVL 5

Expert Comment

by:cer
ID: 1780362
Found nothing to quote in MSDN, only this two lines:

Video Init                    VgaStart
Video Save                    VgaSave


0
Want to promote your upcoming event?

Attending an event? Speaking at a conference? Or exhibiting at a tradeshow? Easily inform your contacts by using a promotional banner in your email signature. This will ensure your organization’s most important contacts are in the know.

 

Author Comment

by:digiscrae
ID: 1780363
My issue is not specifically with fullscreen mode.  As stated in the original question, I need to reserve the B0000 range for my proprietary piece of hardware.  VGASAVE is residing from A0000 to BFFFF.  My s/w apps do open DOS windows but it is not required nor is it likely that they will ever need to go to Fullscreen mode.  The only concern is if it could cause a video dump on the field.   I tested a few things with VGASAVE disabled and things seemed to be okay.   At this point, I think CER hit it on the head but I was awaiting some documentation to refer to.   My Technet CD is offline right now, and I won't have it til later today.  I will refer to it once I am able to access the resource.  

Eizen, no offense - but I think Cer beat you to the solution.   I appreciate your input, though...
0
 
LVL 5

Expert Comment

by:y96andha
ID: 1780364
A0000 to AFFFF is the standard VGA memory area. B0000 to B7FFF is the hercules monochrome adapter display area. B8000 to BFFFF is the standard VGA text mode display area.

Some adapters use the whole area from A0000 to BFFFF in SVGA modes, which means that you should avoid putting other memory mapped hardware there. You might run into some real trouble if you switch to another graphics adapter later, having the display driver write screen data to your proprietary piece of hardware.

Do you really have to use that address? If you decide to use it, be aware of the risks.

0
 
LVL 5

Expert Comment

by:cer
ID: 1780365
OK, maybe i swapped VGA and Hercules Adress range.
Since this hardware works OK it seems to use the hercules text area (B0-B7).
All these adresses resides in the first MB and are for DOS (!)
I am not sure how NT handle this and if the NT video driver can map it elsewhere. However, in a DOS-Box it is there to be compatible. If the Box is not full screen NT driver and grafix mode is used, in Full screen a seperate driver (VGASAVE?) is used (because of this it is difficult to change the font in fullscreen).

My understanding of this matter is about 80% in the moment. So far I would say the only problem which arises is that you can not use full screen (as you described). Since I have no more information, this is my answer. If you agree, you can grade this comment.

0
 

Author Comment

by:digiscrae
ID: 1780366
Cer, please lock the question so that I may award the points.

y96andha:   Unfortunately, I have no choice but to use the B0000 range for this device.   The only other option is to move the Adaptec AHA2940 from the D0000 range.   In the SCSI BIOS, there is no way to change it, and since it's PCI (Plug & Pray), there are no jumpers on the board.   The original SCSI adapter used in this unit was an AHA1520 which allowed the configuration of the memory address.   In this scenario, the SCSI adapter locks down the memory address before the S3 Video Chipset & the proprietary board I have are able to.  The chances of the video adapter being changed are slim to none because the video is incorporated into the system board and can handle much more than what this application will ever need.   In essence, these units are high-octane dumb terminals that only perform three tasks that require very little user interaction.  Basically, what I'm trying to say is that these machines will not be used to play Quake or look at nudie pics.  ;)    

I appreciate your input on this subject, but Cer is going to get the points.  I hope there is no offense, but he's been with me on this for a week now, and I feel I owe him the credit.
0
 
LVL 5

Accepted Solution

by:
cer earned 170 total points
ID: 1780367
I would say the only problem which arises is that you can not use full screen.
0
 
LVL 5

Expert Comment

by:y96andha
ID: 1780368
OK, once you've accepted the answer, I won't be able to read any more comments on this question. I guess that if you won't be using it on some other machine, or with an other graphics adapter, there should be minimal risks for trouble. Good luck!
0
 

Author Comment

by:digiscrae
ID: 1780369
Thanks again, Cer!
0
 

Expert Comment

by:cocolapaille
ID: 7777218
VGASAVE is enabled by default and should not be disabled. If you disable it and reboot, there is a strong chance the system may not boot, since during boot-time it is used as a fail-safe. Many users have reported that they disabled it in the mistaken assumption they were freeing up system resources by doing so, only to discover their system was now unbootable. If VGASAVE was disabled, you can reset it by booting to the Recovery Console and typing enable vgasave service_system_start at the command prompt.
0
 

Expert Comment

by:cocolapaille
ID: 7777222
VGASAVE, which designed to load automatically when the default designated video card driver does not work, or if a newly installed video card driver refuses to work.
0

Featured Post

Why You Should Analyze Threat Actor TTPs

After years of analyzing threat actor behavior, it’s become clear that at any given time there are specific tactics, techniques, and procedures (TTPs) that are particularly prevalent. By analyzing and understanding these TTPs, you can dramatically enhance your security program.

Join & Write a Comment

Recently Microsoft released a brand new function called CONCAT. It's supposed to replace its predecessor CONCATENATE. But how does it work? And what's new? In this article, we take a closer look at all of this - we even included an exercise file for…
Today, still in the boom of Apple, PC's and products, nearly 50% of the computer users use Windows as graphical operating systems. If you are among those users who love windows, but are grappling to keep the system's hard drive optimized, then you s…
Windows 8 comes with a dramatically different user interface known as Metro. Notably missing from the new interface is a Start button and Start Menu. Many users do not like it, much preferring the interface of earlier versions — Windows 7, Windows X…
Get a first impression of how PRTG looks and learn how it works.   This video is a short introduction to PRTG, as an initial overview or as a quick start for new PRTG users.

758 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

21 Experts available now in Live!

Get 1:1 Help Now