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# ATI Graphics Pro Turbo Video DAC Incorrectly Detected

Article ID: 124035

Article Last Modified on 11/1/2006

APPLIES TO

- Microsoft Windows NT Workstation 3.5
- Microsoft Windows NT Server 3.5

This article was previously published under Q124035

## SYMPTOMS

When you upgrade or install Windows NT version 3.5 on a computer with an ATI Graphics Pro Turbo PCI video card, Windows NT Setup detects the video card as an ATI Graphics Compatible Adapter. Only 16 and 256 colors are supported for any resolution.
If you manually configure the video card to use the ATI Graphics Pro Turbo video adapter driver, only 16 and 256 colors are available and the Test option of Display in Control Panel fails.

## CAUSE

This problem occurs because the DAC (Digital-to-Analog Converter) is incorrectly identified as a Brooktree BT-47x DAC instead of an ATI 68860 DAC.

## RESOLUTION

If the ATI Graphics Pro Turbo PCI video adapter is detected as using a Brooktree BT-47x DAC, call the ATI bulletin board system (BBS) at (905) 764-9404 and download 64NT35.ZIP. Extract the contents of 64NT35.ZIP and follow the installation instructions. For more information, contact ATI Technical Support at (905) 882-2600.
To verify the DAC type:

1. Run Control Panel and choose Display.
2. Choose the Change Display Type button.
3. Verify that the Adapter Type is the ATI Graphics Pro Turbo.
4. Verify that the DAC type in Adapter Information is ATI 68860.

The ATI product discussed here is manufactured by ATI Technologies, Inc., a vendor independent of Microsoft; we make no warranty, implied or otherwise, regarding the product's performance or reliability.

Additional query words: prodnt brook tree

Keywords: KB124035