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Display Features

Mode recognition

For any SVGA/VGA/EGA display mode, the driver can properly address the entire screen. ANSIPLUS automatically recognizes and adapts to various VGA or EGA screen modes, both text and graphics, including extended modes with large numbers of lines and/or columns. ANSIPLUS can also automatically adapt to and compensate for older video controllers with very limited numbers of colors or shades (eg., CGA or monochrome boards). 


In text and in 16-color VGA/EGA graphics display modes, the driver bypasses the ROM BIOS and goes straight to the video RAM, so it can operate much faster than either the original DOS console driver or the DOS ANSI driver. Programs that write large character strings to the standard output (console) file handle in "raw" mode can generate their output many times faster.

Color selection

ANSIPLUS provides full control over colors. In color text modes, sixteen foreground and background colors are supported. In 16-color VGA/EGA graphics modes, ANSIPLUS allows mixing of background colors, for a total of 136 possible background colors. In 256-color VGA graphics modes, all 256 foreground and background colors are supported.

Palette control

Control over VGA/EGA palette registers and VGA DAC registers allows selecting and maintaining colors using the video controllerís full capabilities. The driver traps all video mode changes, and installs the palette and/or DAC colors of the userís, or of ANSIPLUSís color scheme. Applications that set their own palettes will continue to do so, but those that do not can now use custom color choices. Blinking can also be kept disabled to allow 16 background colors in text modes.

Text size

ANSIPLUS allows selection of alternate VGA/EGA character sets, giving control over the character height, and thus the number of text lines used in any VGA/EGA video mode. On a standard VGA, for example, the driver supports 80 column text with 25, 26, 28, 30, 33, 36, 40, 44 and 50 lines.

Smooth scrolling

ANSIPLUS supports smooth scrolling of the screen (for fast CPUs with 16-bit VGA/EGA), so the screen can be read while it is moving. Options are provided to control the use and rate of smooth scrolling.

Extended modes

The ANSI Set Mode control sequence has been expanded to allow specifying SVGA/VGA/EGA modes that are based on full AX and/or BX CPU register values, extending ANSI-type control to Super VGA/EGA controllers that require such register settings. Super VGA controllers that conform to the VESA standard are also automatically recognized, and VESA extended set mode calls are made by the ANSIPLUS driver for modes of 100h or higher.

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© Copyright 2000-2007, Kristofer Sweger. All rights reserved.
Rev. 10/16/07