Super FX

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Super FX-rendered 3D polygon graphics in the SNES game Star Fox
Super FX 2 chip on Super Mario World 2: Yoshi's Island
MARIO CHIP 1 (Super FX) chip on Starwing

The Super FX is a family of coprocessor chip used in select Super Nintendo (SNES) video game cartridges. This custom-made RISC processor is typically programmed to act like a graphics accelerator chip that would draw polygons to a frame buffer in the RAM that sits adjacent to it. For those games, the data in this frame buffer is periodically transferred to the main video memory inside of the console using DMA in order to show up on the television display.

The Super FX chip was designed by Argonaut Games, who also co-developed (with Nintendo) the 3D space scrolling shooter video game Star Fox to demonstrate the additional polygon rendering capabilities that the chip had introduced to the SNES. While in development, the Super FX chip was codenamed "MARIO", which is an acronym for "Mathematical, Argonaut, Rotation & Input/Output".[1] Compared with the graphics of modern 3D games, the graphics appear very simple. Although Star Fox is capable of rendering polygons, the number of polygons is in the hundreds as opposed to the millions of today's games. Star Fox uses scaling bitmaps for lasers, asteroids, and other obstacles, but other objects such as ships are rendered with polygons. With the release of Star Fox in 1993, the Super FX became the best selling RISC-based processor at that time.[1]

In addition to rendering 3D polygons, the chip is also used to assist the SNES in rendering advanced 2D effects. Super Mario World 2: Yoshi's Island uses it for advanced graphics effects like sprite scaling and stretching, for huge sprites that allowed for boss characters to take up the whole screen, and for multiple foreground and background parallax layers to give a greater illusion of depth.

The first version of the chip, commonly referred to as simply "Super FX", is clocked with a 21 MHz signal, but an internal clock speed divider halves it to 10.5 MHz. Later on, the design was revised to become the Super FX GSU-2; this, unlike the first Super FX chip revision, is able to reach 21 MHz.

All versions of the Super FX chip are functionally compatible in terms of their instruction set. The differences arise in how they are packaged, their pinout, and their internal clock speed. As a result of changing the package when creating the GSU-2, more external pins were available and assigned for addressing. As a result, a larger amount of external ROM or RAM can be accessed.

Game cartridges that contain a Super FX chip have additional contacts at the bottom of the cartridge that connect to the extra slots in the cartridge port that are not otherwise typically used. Therefore, Super FX games can not be plugged into cartridge adapters which predate the release of Super FX games. This includes cheat devices, such as the Game Genie.

Because of higher manufacturing costs, games that include additional hardware such as the Super FX chips retailed at a higher MSRP than most SNES games.

Super FX games[edit]

Super FX 2 games[edit]

Unreleased games[edit]

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