Sega Virtua Processor
The practice of adding special chips to game cartridges had first been seen in various games on the NES. These chips effectively increased the console's capabilities, enabling visual effects such as split-screen scrolling (Super Mario Bros. 3) and enhanced tile switching (Kirby's Adventure). This concept was expanded on the SNES console with on-cartridge DSP chips and RISC processors (notably the Super FX chip used in Star Fox). The Super FX in particular enabled the console to render polygons in real time, as well as enabling scaling, rotation and stretching of much larger sprites than the console could handle on its own (Super Mario World 2: Yoshi's Island). The external processors boosted the console's overall performance by offloading most of the rendering tasks from the main CPU.
As these enhancements became more commonplace on the SNES, the stock of existing Mega Drive games began to look outdated in comparison. Sega quickly began work on an enhancement chip to compete with Nintendo's Super FX, resulting in the Sega Virtua Processor chip. The chip enabled the Mega Drive to render polygons in real time and provided an "Axis Transformation" unit that handled scaling and rotation. Virtua Racing, the only game released for the Mega Drive to use this chip, ran at a significantly higher and more stable frame rate than similar games on the SNES.
However, the chip was expensive to produce and increased the cost of the games that used it. At US$100, Virtua Racing was the most expensive domestic Genesis cartridge to be mass-produced. Two other games, Virtua Fighter and Daytona USA, were confirmed to have been planned for the SVP chip as well, but were instead moved into the Saturn's launch line-up.
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