DOSBox Staging 0.83: How 3dfx Voodoo Emulation Works and What Glide Games Need

DOSBox Staging 0.83 emulates the 3dfx Voodoo at the hardware level, without OpenGL passthrough or other shortcuts. According to the official 0.83 manual, that approach is CPU-intensive but highly accurate, and Voodoo emulation is enabled by default. This article summarizes what the documentation says; the steps and settings below have not been hands-on tested.

The hardware being emulated

The 3dfx Voodoo was released in 1996 as a dedicated 3D-only accelerator: it handled 3D rendering and nothing else. It was installed alongside a regular video card, with the two connected by a pass-through cable. The manual credits it with smoother geometry, bilinear filtering and atmospheric fog effects that were not possible on a CPU alone.

What is enabled by default

• Documented defaults in the 0.83 manual:
• - Voodoo emulation is enabled by default, so most DOS Glide games should work out of the box.
• - Bilinear filtering is on by default, matching real Voodoo hardware, which always applied bilinear texture filtering. Disabling it gives a sharper but less authentic look.
• - The thread setting defaults to auto, which uses up to 16 threads based on available CPU cores.

If a game does not use Voodoo graphics, the manual states there is no performance penalty whatsoever.

GLIDE2X.OVL: the driver most Glide games need

Most Glide games need a DOS driver file called GLIDE2X.OVL in the game's directory. Many games shipped with their own version of this driver. For games that did not, you need to supply a suitable one, and the manual notes that not all drivers work with every game.