Full-screen DOS Window Is Split with Some Number 9 Video Cards

ID: Q197538

The information in this article applies to:

Microsoft Windows NT Workstation version 4.0
Microsoft Windows NT Server version 4.0
Microsoft Windows NT Server version 4.0, Terminal Server Edition

SYMPTOMS

Starting a full-screen command prompt on some Number Nine video adapters may result in a split-screen doubling of the full screen.

CAUSE

Vga.sys needs to set the character cell height for the MS-DOS mode. Character cell height is held in the lower 5 bits of the VGA register CR9. However, Vga.sys destroys the upper 3 bits of CR9 when writing the character cell height into the lower 5 bits of the register. The state of one of those upper three bits is required by the flat-panel MS-DOS mode.

RESOLUTION

To resolve this problem, obtain the latest service pack for Windows NT 4.0 or Windows NT Server 4.0, Terminal Server Edition. For additional information, please see the following article in the Microsoft Knowledge Base:

Q152734 How to Obtain the Latest Windows NT 4.0 Service Pack

If obtaining the service pack at this time is not a viable alternative, you can contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information on support costs, please go to the following address on the World Wide Web:

http://support.microsoft.com/support/supportnet/default.asp

The English version of this fix should have the following file attributes or later:


   Date      Time                 Size    File Name     Platform
   -------------------------------------------------------------
   10/27/98  11:08a                14,704 Vga.sys       (x86)
   10/27/98  11:08a                22,832 Vga.sys       (Alpha)

NOTE: If this product was already installed on your computer when you purchased it from the Original Equipment Manufacturer (OEM) and you need this fix, please call the Pay Per Incident number listed on the above Web site. If you contact Microsoft to obtain this fix, a fee may be charged. This fee is refundable if it is determined that you only require the fix you requested. However, this fee is non-refundable if you request additional technical support, if your no-charge technical support period has expired, or if you are not eligible for standard no-charge technical support.

For more information about eligibility for no-charge technical support, see the following article in the Microsoft Knowledge Base:

Q154871 Determining If You Are Eligible for No-Charge Technical Support

STATUS

Microsoft has confirmed this to be a problem in Windows NT 4.0 and Windows NT Server 4.0, Terminal Server Edition. This problem was first corrected in Windows NT 4.0 Service Pack 4.0 and Windows NT Server 4.0, Terminal Server Edition Service Pack 4.

Additional query words: 4.00 #9 Number 9 video card display adapter

Keywords : NT4SP4Fix kbbug4.00 kbfix4.00 kbfix4.00.sp4
Version : winnt:4.0
Platform : winnt
Issue type : kbbug