Super Nintendo Entertainment System Game Pak

Super Nintendo Entertainment System Game Pak
Media type ROM cartridge
Encoding Digital
Capacity 117.75 Mbit (48 Mbit usual)
Developed by Nintendo
Usage Super Nintendo Entertainment System

The cartridge media of the Super Nintendo Entertainment System officially referred to as Game Pak in most Western regions,[1] and as Cassette (カセット Kasetto) in Japan and parts of Latin America.[2] While the SNES can address 128 Mbit,[lower-alpha 1] only 117.75 Mbit are actually available for cartridge use. A fairly normal mapping could easily address up to 95 Mbit of ROM data (63 Mbit at FastROM speed) with 8 Mbit of battery-backed RAM.[3] However, most available memory access controllers only support mappings of up to 32 Mbit. The largest games released (Tales of Phantasia and Star Ocean) contain 48 Mbit of ROM data,[4][5] while the smallest games contain only 2 Mbit.

Cartridges may also contain battery-backed SRAM to save the game state, extra working RAM, custom coprocessors, or any other hardware that will not exceed the maximum current rating of the console.

Enhancement chips

As part of the overall plan for the SNES, rather than include an expensive CPU that would still become obsolete in a few years, the hardware designers made it easy to interface special coprocessor chips to the console (just like the MMC chips used for most NES games). This is most often characterized by 16 additional pins on the cartridge card edge.[6]

The Super FX is a RISC CPU designed to perform functions that the main CPU could not feasibly do. The chip was primarily used to create 3D game worlds made with polygons, texture mapping and light source shading. The chip could also be used to enhance 2D games.[7]

The Nintendo fixed-point digital signal processor (DSP) chip allowed for fast vector-based calculations, bitmap conversions, both 2D and 3D coordinate transformations, and other functions.[8] Four revisions of the chip exist, each physically identical but with different microcode. The DSP-1 version, including the later 1A and 1B bug fix revisions, was used most often; the DSP-2, DSP-3, and DSP-4 were used in only one title each.[9]

Similar to the 5A22 CPU in the console, the SA-1 chip contains a 65c816 processor core clocked at 10 MHz, a memory mapper, DMA, decompression and bitplane conversion circuitry, several programmable timers, and CIC region lockout functionality.[7]

In Japan, games could be downloaded for a fee from Nintendo Power kiosks onto special cartridges containing flash memory and a MegaChips MX15001TFC chip. The chip managed communication with the kiosks to download ROM images, and provided an initial menu to select which of the downloaded games would be played. Some titles were available both in cartridge and download form, while others were download only. The service was closed on February 8, 2007.[10]

Many cartridges contain other enhancement chips, most of which were created for use by a single company in a few titles;[9] the only limitations are the speed of the Super NES itself to transfer data from the chip and the current limit of the console.

References

  1. ↑ "Game Pak Troubleshooting". Customer Service. Nintendo of America, Inc. Retrieved 2010-08-23.
  2. ↑ ゼルダの伝説 神々のトライフォース 取扱説明書. Nintendo Co., Ltd. 1991-11-21. p. 1.
  3. ↑ Cite error: The named reference anomie_memmap was invoked but never defined
  4. ↑ Ogasawara, Nob (November 1995). "Future Fantasies from overseas". GamePro. San Mateo, CA: Infotainment World. 7 (11): 126. ISSN 1042-8658.
  5. ↑ "Star Ocean". Nintendo Power. Redmond, WA: Nintendo of America (86): 60–61. July 1996. ISSN 1041-9551.
  6. ↑ Cite error: The named reference anomie_ports was invoked but never defined
  7. 1 2 (2007-05-01) Snes9x readme.txt v1.51. Snes9x. Snes9x. Retrieved on 2007-07-03.
  8. ↑ Overload (2006-05-29). "Digital Signal Processing". Overload's Puzzle Sheet. Archived from the original on 2007-03-11. Retrieved 2007-05-09. Refer to the command summaries for all four DSP versions.
  9. 1 2 Nach; Moe, Lord Nightmare. "SNES Add-on Chip information". Archived from the original on 2007-07-08. Retrieved 2007-05-09.
  10. ↑ "Nintendo Power". N-Sider.com. Retrieved 2007-07-03.
  1. ↑ Cite error: The named reference binary_prefix was invoked but never defined
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