Amiga 3Dfx Voodoo FAQ

General info on the Voodoo

• What is the Voodoo?
• What are the requirements for the Voodoo board?
• What is the specification of the Voodoo board?
• What is the Voodoo Rush?
• Why is the Voodoo module Zorro III only?
• Why not use the Voodoo II chipset?
• What performance can I expect from the Voodoo?
• Whare can I find documentation on programming the Voodoo?

The Voodoo name refers to the chip set made by 3Dfx. It is designed to speed up 3D graphics by drawing polygons very quickly. Unlike the Virge chip sets used in the CyberVision graphics cards from phase 5, it does not have a set up engine, but can draw polygons much faster and will result in a better performance increase than the Virge (as used in the CyberVision boards).

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What are the requrements for the Voodoo board? The Voodoo board will requre a Zorro III Amiga (like the A4000 or A3000) and a Picasso IV graphics card. Most software will require Warp3D to work with it.

A 68060 cpu is highly recommended, as the Voodoo relys on the cpu to calculate all polygon data.

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What is the spec of the Voodoo board The Voodoo board is exactly the same as the Mac version made by Village Tronic. It has a Voodoo 1 chipset with 12mb of on-board memory for use as a frame and texture buffer by the Voodoo. The actual specs of the Voodoo chip set are as follows: Standard 3D Features

• Perspective corrected texture mapping
• Bi-linear and advanced texture filtering
• Level of detail (LOD) MIP mapping
• Sub-pixel correction
• Polygonal-based Gouraud shading and texture modulation
• 24-bit internal, 16-bit dithered RGB frame buffer
• Multiple format texture buffer (8-bit and 16-bit)
• 1, 2, and 4 Mbytes of frame/aux buffer memory per pixelfx
• 1, 2, and 4 Mbytes of texture memory per texelfx

Scalable Performance

• 45 Mpixels/sec sustained fill rate for bi-linear or advanced filtered textures
• Over 1M triangles/sec for filtered, LOD MIP-mapped, Z-buffered, alpha-blended, fogged, textured 25-pixel triangles

Additional Features

• Anti-aliasing
• Depth buffering (16-bit)
• Alpha blending
• Per-pixel special effects: fog, transparency, translucency
• Texture compositing, morphing, animation
• Linear frame buffer access

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What is the Voodoo Rush The Voodoo Rush is basically the same thing as the Voodoo, but with added features like rendering in a window and built in 2D chip set. The performance is the same as the Voodoo.

Note that the Amiga Voodoo board already supports rendering in a window using the picture-in-picture features of the Picasso IV.

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Why is the Voodoo module Zorro III only? The Voodoo chipset requires 16mb of address space. Even the 8mb version needs this. The Zorro II bus only supports 8mb of address space, so it cannot be used on anything but Zorro III. Also, the Zorro II bus does not support the 32bit memory access that the board needs.

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Why was the Voodoo 1 chosen over the Voodoo 2? There are a number of reasons. Klaus Burkert explained them on the Picasso mailing list, and I have included breif versions of what he said here:

• The Voodoo 2 chipset runs too hot for desktop Amiga cases, as it nearly melts the PCB.

• The Voodoo 2 chipset requires three chips (1 pixel unit and 2 texture units) and so would not fit onto the Picasso IV without using another Zorro slot or blocking other modules.

• Due to the limits of the Zorro bus and the Amiga 68k processors even the Voodoo 1 will probably not be saturated (pushed to the limit) by current systems, so there is little point in having all the extra power of the Voodoo II.

• The cost of producing a Voodoo 2 board would be too high. The Voodoo 1 nearly didn't go ahead, and it is simply an adaptation of the Mac Voodoo module (only the PCB is changed). To make a Voodoo 2 module would require a whole new PCB design, adaptation of the PC schematics and a lot of testing work that would push the cost too high.