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AST RESEARCH, INC.          TECHNICAL BULLETIN # 1198               5-31-95

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BRAVO MT HANGS RUNNING 800x600x16M IN WINDOWS NT 3.5


PROBLEM

After selecting the video mode from 'Display' in the 'Control Panel' menu, 
the Bravo MT system (with a 2MB video memory) hangs when trying to run 
the Windows NT 3.5 Workstation in 800x600x16.8 million color graphics mode. 

The system also hangs at the 800x600x16.8 million color video mode in 
Windows NT 3.1 server systems.

In Windows 3.1 (ATI Mach 32 driver Ver. 1.02 ), the system can not select 
the 800x600x16.8 million color mode from the ATI driver.


CAUSE

The RAMDEC for the integrated ATI Mach 32 video chip on the Bravo MT system 
does not support the graphic type of 800x600x16.8 million color mode.


SYSTEMS AFFECTED
AST PART NUMBER AND DESCRIPTION

501278-XXX      BRAVO MT 4/33
501279-XXX      BRAVO MT 4/66D
501447-XXX      BRAVO MT 4/33S
501459-XXX      BRAVO MT 4/50S


SOLUTION

The Bravo MT system does support the 800x600x16.8 million color graphic 
mode.  However, the system does support 640x480x16.8 million colors, 
1280x1040x256 colors, and other standard video modes.