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The Sega Saturn is equipped with dual custom VDP chips for graphics processing. The VDP1 chip is primarily responsible for sprite generation. Polygon generation is accomplished through manipulation of the sprite engine. Texture mapping and Gouraud shading is also handled by the VDP1.
The VDP1 renders primitives to two 256 kB frame buffers that can be configured as 512x512x8 or 512x256x16 (Virtua Fighter 2 was the first game to use high resolution, at 60 frame/s on Consoles). Having two frame buffers allows double buffering of the display and provides more time for rendering. The active framebuffer is read out to the display by the VDP2, which can apply data from a coefficient table to modify the scanning process, for effects like rotation, scaling, and general distortion of the entire frame buffer as a single entity.
The SCU (system bus control unit) provides DMA across a dedicated bus commonly labeled as the "B-bus" that the VDP2 and VDP1 are connected to, allowing transfer of data from them to and from main memory. Keep note that transferring data from and to the same bus is prohibited by all 3 SCU DMA levels.