Technical Information

What's Emulated?

• 65c816 main CPU.
• Variable length machine cycles.
• 8 channel DMA and H-DMA.
• H-IRQ, V-IRQ and NMI.
• Sony SPC700 sound CPU.
• Sound DSP, with eight 16-bit, stereo channels, compressed samples, hardware envelope processing, echo, pitch modulation and digital FIR sound filter.
• SRAM, a battery-backed RAM.
• All background modes, 0 to 7.
• All screen resolutions including interlace mode.
• Pseudo hi-res mode.
• 8x8, 16x8 and 16x16 tile sizes, flipped in either direction.
• 32x32, 32x64, 64x32 and 64x64 screen tile sizes.
• Vertical and horizontal offset-per-tile.
• 128 8x8, 16x16, 32x32 and 64x64 sprites, flipped in either direction.
• Sub-screen and fixed color blending effects.
• Mosaic effects.
• Mode 7 screen rotation, scaling and screen flipping.
• Single and dual graphic clip windows, with all four logic combination modes.
• Color blending effects only inside or outside a window.
• Palette changes during frame.
• Direct color mode - uses tile and palette-group data directly as RGB value.
• SNES Mouse.
• Super Scope, emulated using computer mouse.
• Justifier, by Konami, similar to the Super Scope and used only in Lethal Enforcers.
• Multi Player 5, allowing up to five people to play games simultaneously on games that support that many players.
• Super FX, a fast RISC CPU used in several games.
• SA-1, a faster version of main CPU with some functions, used in several games.
• DSP-1, a custom chip used in several games, mainly racing games.
• DSP-2, a custom chip used only in Dungeon Master.
• DSP-4, a custom chip used only in Top Gear 3000.
• C4, a sprite scaler/rotator/line drawer/simple maths co-processor chip used only in Megaman X2 and X3.
• Seta-10, a custom chip used only in F1 Race of Champions 2.
• OBC1, a sprite management chip used only in Metal Combat.
• S-DD1, a data decompression chip used only in Star Ocean and Street Fighter 2 Alpha.
• SPC7110, similar in use to S-DD1, used in a few Hadoson games.
• S-RTC, a real-time clock chip, used only in Dai Kaijyu Monogatari 2.
• Satellaview and BS-X, only partially.

What's Not?

• Exact sub-cycle timings of communication among most of parts - main CPU, sound CPU, DMA, H-DMA, IRQ, NMI, and so on. Snes9x cannot run games that require severe timings!
• Any other odd chips that manufactures sometimes placed inside the cartridge to enhance games and as a nice side-effect, also act as an anti-piracy measure. (DSP-3, Seta-11 and Seta-18, as examples)
• The expansion slot found in many carts.

Custom Chips

Super FX

The Super FX is a 10.5/21MHz RISC CPU developed by Argonaut Software used as a game enhancer by several game titles. Released SNES Super FX games included Yoshi's Island, Doom, Winter Gold, Dirt Trax FX, StarFox, Stunt Race FX and Vortex.

SA-1

The SA-1 is a fast, custom 65c816 8/16-bit processor, the same as inside the SNES itself, but clocked at 10MHz compared to a maximum of 3.58MHz for the CPU inside the SNES. The SA-1 isn't just a CPU; it also contains some extra circuits developed by Nintendo which includes some very fast RAM, a memory mapper, DMA and, several real-time timers.

C4

The C4 is custom Capcom chip used only in the Megaman X2 and Megaman X3 games. It can scale and rotate images, draw line-vector objects and do some simple maths to rotate them.

S-DD1

The S-DD1 is a custom data decompression chip that can decompress data in real-time as the SNES DMA's data from the ROM to RAM. Only two games use the chip: Star Ocean and Street Fighter Alpha 2.

SPC7110

The SPC7110 is a compression and memory mapping chip. It provides a few extra features as well. It functions as an RTC interface, and has a multiply/divide unit that has more precision than the SNES. The SPC7110 is found only in 4 games: Super Power League 4, Far East of Eden Zero, Far East of Eden Zero - Shounen Jump no Shou and Momotaro Dentetsu Happy.

Others

Other known custom chips: DSP-1, DSP-2, DSP-3, DSP-4, Seta-10, Seta-11, Seta-18, OBC1 and S-RTC.