List of Super NES Enhancement Chips - Super FX

Super FX

The Super FX chip is a 16-bit supplemental RISC CPU developed by Argonaut Games that was included in certain game cartridges to perform functions that the main CPU could not feasibly do. It was typically programmed to act as a graphics accelerator chip that would draw polygons to a frame buffer in the RAM that sat adjacent to it.

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

This chip went through at least four revisions, first starting out as a surface mounted chip labeled MARIO CHIP 1 (Mathematical, Argonaut, Rotation & I/O) in the earliest Star Fox cartridges, commonly called the Super FX. The following year some boards were providing an epoxy version of it, and later a first revision came out under the label GSU-1. Both versions are clocked with a 21 MHz signal, but an internal clock speed divider halved it to 10.5 MHz on the MARIO CHIP 1. The GSU-1 however ran at the full 21 MHz. Both the MARIO CHIP 1 and the GSU-1 could support a ROM size of maximum 8 MBit. Later on, the design was revised to become the GSU-2, known as the Super FX 2 which was still 16bit, but unlike the earlier Super FX chips, this version could support a ROM size higher than 8 MBit. The final known revision was the GSU-2-SP1 (Service Pack 1) which probably fixed some issues or optimized the earlier revision, but the details are unknown. 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 pin out, their maximum supported ROM size and their internal clock speed.

Variants of the Super FX chip sorted chronologically