1001 Secrets for Windows NT Registry
(Publisher: 29th Street Press)
Author(s): Tim Daniels
ISBN: 1882419685
Publication Date: 12/01/97

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When set to 1, this value enables the faster AUTOLINE opcode of the drawing engine to draw lines defined by integer coordinates. The convention that determines which pixels contribute to a given line is slightly different in AUTOLINE and in Windows NT. Setting AlternateLines to 1 trades off compliance with the Windows NT conventions for performance. A value of 0 enforces compliance. Lines defined by non-integer endpoint coordinates are not affected by this setting.

11-25 Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Services\mga64\Device0
Value Name: User.ComplexBlt
Data Type: REG_BINARY
Value: 1

Device0 in the key refers to the first video card installed on your system. When set to 1, this value lets your video card hardware accelerate some complex Raster OPerations (ROPs) by executing a sequence of simple ROPs (ORing, ANDing, etc.) on the display. Artifacts in the target display area may flash because an intermediate result, which will be replaced by the final image on the next cycle, is displayed in video RAM on a given refresh cycle. A value of 0 for the entry means that complex ROPs are performed in software.

II-26 Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Services\mga64\Device0
Value Name: User.DeviceBitmaps
Data Type: REG_BINARY
Value: 1

Device0 in the key refers to the first video card installed on your system. Setting this value to 1 lets the hardware accelerate drawing bitmaps by using off-screen memory for caching them. A value of 0 disables bitmap caching and lets the CPU draw onto all bitmaps. Bitmap caching is internally disabled when a desktop requiring more than one card is in use, regardless of the registry setting.

II-27 Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Services\mga64\Device0
Value Name: User.EnableUSWC
Data Type: REG_BINARY
Value: 1

Device0 refers to the first video card installed on your system. When set to 1, the value lets the frame buffer directly access the write-combining feature of the Pentium Pro processor. Setting this value to 0 may result in slightly slower performance.

II-28 Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Services\mga64\Device0
Value Name: User.MgaInfoFile
Data Type: REG_BINARY
Value: 1

Device0 refers to the first video card installed on your system. When set to 1, this value lets the MGA PowerDesk software control refresh rates. A value of 0 allows all available refresh rates to be listed.

II-29 Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Services\mga64\Device0
Value Name: User.SynchronizeDac
Data Type: REG_BINARY
Value: 0


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