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Senin, 31 Maret 2008

Super Nintendo Entertainment System

The Super Nintendo Entertainment System or Super NES (also called SNESa[›] and Super Nintendo) is a 16-bit video game console that was released by Nintendo in North America, Europe, Australasia (Oceania), and South America between 1990 and 1993. In Japan and Southeast Asia, the system is called the Super Family Computer, Super Famicom (スーパーファミコン Sūpā Famikon?), or SFC for short. In South Korea, it is known as the Super Comboy and was distributed by Hyundai Electronics. Although each version is essentially the same, several forms of regional lockout prevent direct compatibility.

The Super Nintendo Entertainment System was Nintendo's second home console, following the Nintendo Entertainment System (NES). The console introduced advanced graphics and sound capabilities that compensated for its relatively slow CPU, compared with other consoles at the time. Additionally, the system's support for numerous enhancement chips (which shipped as part of certain game cartridges) helped to keep it competitive in the marketplace.

The SNES was a global success, becoming the best-selling console of the 16-bit era despite its relatively late start and the fierce competition it faced in North America from Sega's Genesis console. Some consider the SNES to embody the "Golden Age of video games", citing its many groundbreaking games and the perceived focus on gameplay over graphics and technical gimmicks.[4] Others question this perceived romanticism, believing the system was just another step in the evolution of video game technology.[5] The SNES remained popular well into the 32-bit era, and although Nintendo has dropped all support for the console, it continues to be popular among fans, collectors, and emulation enthusiasts, some of whom are still making "homebrew" ROM images.

Contents

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[edit] History

To compete with the popular NES/Famicom, NEC launched the TurboGrafx-16/PC-Engine in 1987, and Sega followed suit with the Genesis/Mega Drive in 1988. Both systems were built on 16-bit architectures and offered improved graphics and sound over the 8-bit NES. However, the NES would continue to dominate the gaming market for several years before Sega's system finally became successful.[6] Nintendo executives were initially reluctant to design a new system, but they reconsidered when the NES hardware began to show its age. Seeing its dominance in the market slipping, Nintendo was compelled to create a new console to compete with its 16-bit rivals.[7]

[edit] Launch

Designed by Masayuki Uemura, the designer of the original Famicom, the Super Famicom was released in Japan on Wednesday November 21, 1990 for ¥25,000 (US$210). It was an instant success: Nintendo's initial shipment of 300,000 units sold out within hours, and the resulting social disturbance led the Japanese government to ask video game manufacturers to schedule future console releases on weekends.[8] The system's release also gained the attention of the Yakuza, leading to a decision to ship the devices at night to avoid robbery.[9]

With the Super Famicom quickly outselling its chief rivals, Nintendo reasserted itself as the leader of the Japanese console market.[10] Nintendo's success was partially due to its retention of most of its key third-party developers from its earlier system, including Capcom, Konami, Tecmo, Square Co., Koei, and Enix.[11]

"Nintendo's strongest selling point, however, was the game that came packed in with the Super NES console—Super Mario World."
"Nintendo's strongest selling point, however, was the game that came packed in with the Super NES console—Super Mario World."[12]

In August 1991,b[›] Nintendo released the Super Nintendo Entertainment System, a redesigned version of the Super Famicom, in North America for US$199. The SNES was released in the United Kingdom and Ireland in April 1992 for GB£150, with a German release following a few weeks later. The PAL region versions of the console use the Japanese Super Famicom design, except for labeling and the length of the joypad leads. Both the NES and Super NES were released in Brazil in 1993 by Playtronic, a joint venture between the toy company Estrela and Gradiente.[13]

The Super NES and Super Famicom launched with only a few games, but these games were well-received in the marketplace. In Japan, only two games were initially available: Super Mario World and F-Zero.[14] In North America and Europe, Super Mario World shipped with the console, and other initial titles included F-Zero, Pilotwings (which demonstrated the console's "Mode 7" pseudo-3D rendering capability), SimCity, and Gradius III.[15]

[edit] Console wars

Main article: Console wars

The rivalry between Nintendo and Sega resulted in one of the fiercest console wars in video game history,[16] in which Sega positioned the Genesis as the "cool" console, with edgy advertisements occasionally attacking the competition and more mature titles aimed at older gamers.[17] Despite the Genesis's head start, its much larger library of games, as well as its lower price point,[18] market share between the SNES and the Genesis was about even in April 1992,[19] and neither console could maintain a definitive lead for several years. The Super NES eventually prevailed, dominating the American 16-bit console market,[20] and would even remain popular well into the 32-bit generation.[21]

[edit] Changes in policy

During the NES era, Nintendo maintained exclusive control over titles released for the system—the company had to approve every game, each third-party developer could only release up to five games per year, those games could not be released on another console within two years, and Nintendo was the exclusive manufacturer and supplier of NES cartridges. However, competition from Sega's console brought an end to this practice; in 1990, Acclaim began releasing games for both platforms, with most of Nintendo's other licensees following suit over the next several years; Capcom (which licensed some games to Sega instead of producing them directly) and Square were the most notable holdouts.[22]

Nintendo also maintained a strict censorship policy that, among other things, limited the amount of violence in the games on its systems. One game, Mortal Kombat, would challenge this policy. A surprise hit in arcades in 1992, Mortal Kombat features splashes of blood and finishing moves that often depict one character dismembering the other. Because the Genesis version retained the gore while the SNES version did not, it outsold the SNES version three to one.[23][24]

Game players were not the only ones to notice the violence in this game; US Senators Herb Kohl and Joe Lieberman convened a Congressional hearing on December 9, 1993 to investigate the marketing of violent video games to children.c[›] While Nintendo took the high ground with moderate success, the hearings led to the creation of the Interactive Digital Software Association and the Entertainment Software Rating Board, and the inclusion of ratings on all video games.[23][24] With these ratings in place, Nintendo decided its censorship policies were no longer needed. Consequently, the SNES port of Mortal Kombat II was released uncensored, and this time Nintendo's version outsold Sega's.[23][24]

[edit] 32-bit era and beyond

While other companies were moving on to 32-bit systems, Rare and Nintendo proved that the Super NES was still a strong contender in the market. In November 1994, Rare released Donkey Kong Country, a platform game featuring 3D models and textures pre-rendered on SGI workstations. With its detailed graphics and high-quality music, Donkey Kong Country rivaled the aesthetic quality of games that were being released on newer 32-bit CD-based consoles. In the last 45 days of 1994, the game sold 6.1 million units, making it the fastest-selling video game in history to that date. This game sent a message that early 32-bit systems had little to offer over the Super NES, and helped make way for the more advanced consoles on the horizon.[25][26]

In October 1997, Nintendo released a redesigned SNES 2 in North America for US$99, which included the pack-in game Super Mario World 2: Yoshi's Island.[27] Like the earlier NES 2, the new model was slimmer and lighter than its predecessor, but it lacked S-Video and RGB output, and it was among the last major SNES-related releases in the region. A similarly redesigned Super Famicom Jr. was released in Japan at around the same time.[28]

Nintendo of America ceased production of the SNES in 1999,[29] about two years after releasing Kirby's Dream Land 3 (its last first-party game for the system) on November 27, 1997. In Japan, Nintendo continued production of the Super Famicom until September 2003,[30] and new games were produced until the year 2000, ending with the release of Metal Slader Glory Director's Cut on December 1, 2000.[31]

In recent years, many SNES titles have been ported to the Game Boy Advance, which has similar video capabilities. In 2005, Nintendo announced that SNES titles would be made available for download via the Wii's Virtual Console service.[32] In 2007, Nintendo announced that it would no longer repair Famicom or Super Famicom systems due to an increasing shortage of the necessary parts.[33]

[edit] Emulation

See also: List of SNES emulators

Like the NES before it, the SNES has retained interest among its fans even following its decline in the marketplace. It has continued to thrive on the second-hand market and through console emulation. The SNES has taken much the same revival path as the NES (see History of the Nintendo Entertainment System).

ZSNES v1.51 user interface
ZSNES v1.51 user interface

Emulation projects began with the initial release of VSSMC in 1994, and Super Pasofami became the first working SNES emulator in 1996.[34] During that time, two competing emulation projects—Snes96 and Snes97—merged to form a new initiative entitled Snes9x.[35] In 1997, SNES enthusiasts began programming an emulator named ZSNES.[36] These two have remained among the best-known SNES emulators, although development continues on others as well. Recently there has been a push for exact emulation,d[›] begun in 2003 by members of both the Snes9x and ZSNES teams and others,[37] and currently led by the development of bsnes.[38]

Nintendo took the same stance against the distribution of SNES ROM image files and emulation as it did with the NES, insisting that they represented flagrant software piracy.[39] Proponents of SNES emulation cite discontinued production of the SNES, the right of the owner of the respective game to make a personal backup, space shifting for private use, the desire to develop homebrew games for the system, the frailty of SNES cartridges and consoles, and the lack of certain foreign imports.[40] Despite Nintendo's attempts to stop the proliferation of such projects, emulators and ROM files continue to be available on the Internet.

The SNES was one of the first systems to attract the attention of amateur fan translators: Final Fantasy V was the first major work of fan translation, and was completed in 1997.[41]

Emulation of the SNES is now available on handheld units, such as Sony's PlayStation Portable (PSP),[42] the Nintendo DS[43] and Game Boy Advance,[44] the Gizmondo,[45] and the GP2X by GamePark Holdings,[46] as well as PDAs.[47] Nintendo's Virtual Console service for the Wii marks the introduction of officially sanctioned SNES emulation.

[edit] Technical specifications

The design of the Super NES incorporates a relatively slow CPU (half the speed of the Mega Drive), but the powerful graphics and sound co-processors allowed impressive tiling and Mode 7 effects, many times more colors, and audio quality that represented a massive leap over the competition.[48] Individual game cartridges can easily supply further custom chips as needed.

[edit] Central processing unit

CPU reference
Processor Ricoh 5A22, based on a 16-bit 65c816 core
Clock Rates (NTSC) Input: 21.47727 MHz
Bus: 3.58 MHz, 2.68 MHz, or 1.79 MHz
Clock Rates (PAL) Input: 21.28137 MHz
Bus: 3.55 MHz, 2.66 MHz, or 1.77 MHz
Buses 24-bit and 8-bit address buses, 8-bit data bus
Additional Features
  • DMA and HDMA
  • Timed IRQ
  • Parallel I/O processing
  • Hardware multiplication and division

The CPU is a Nintendo-custom 5A22 processor, based around a 16-bit 65c816 core. The CPU employs a variable bus speed depending on the memory region being accessed for each instruction cycle: the input clock is divided by 6, 8, or 12 to obtain the bus clock rate. Non-access cycles, most register accesses, and some general accesses use the divisor of 6. WRAM accesses and other general accesses use the divisor of 8. Only the controller port serial-access registers use the divisor of 12.[49]

The chip has an 8-bit data bus, controlled by two address buses. The 24-bit "Bus A" is used for general accesses, while the 8-bit "Bus B" is used for support chip registers (mainly the video and audio processors).[49] Normally only one bus is used at a time, however the built in direct memory access (DMA) unit places a read signal on one bus and a write signal on the other to achieve block transfer speeds of up to 2.68 MB/s (MiB/s).[50]

The DMA unit has 8 independent channels, each of which can be used in two modes. General DMA transfers up to 64 KB in one shot, while H-blank DMA (HDMA) transfers 1–4 bytes at the end of each video scanline. HDMA is typically used to change video parameters to achieve effects such as perspective, split-screen, and non-rectangular windowing without tying up the main CPU.[50]

The 5A22 also contains an 8-bit parallel I/O port (which was mostly unused in the SNES); controller port interface circuits, including both serial and parallel access to controller data; a 16-bit multiplication and division unit; and circuitry for generating Non-Maskable interrupts on V-blank and IRQ interrupts on calculated screen positions.[50]

[edit] Video

Video reference
Resolutions Progressive: 256x224, 512x224, 256x239, 512x239
Interlaced: 512x448, 512x478
Pixel Depth 2, 4, 7, or 8 bpp indexed; 8 or 11 bpp direct
Total Colors 32768 (15-bit)
Sprites 128, 32 max per line; up to 64x64 pixels
Backgrounds Up to 4 planes; each up to 1024x1024 pixels
Effects
  • Pixelization (mosaic) per background
  • Color addition and subtraction
  • Clipping windows (per background, affecting color, math, or both)
  • Scrolling per 8x8 tile
  • Mode 7 matrix operations

The picture processing unit (PPU) consists of two separate but closely tied IC packages, which may be considered as a single entity. It also contains 64 KB (KiB) of SRAM for storing video data (VRAM), 544 bytes of object attribute memory (OAM) for storing sprite data, and 512 bytes of color generator RAM (CGRAM) for storing palette data. The PPU is clocked by the same signal as the CPU, and generates a pixel every two or four cycles. Both NTSC and PAL systems use the same PPU chips, with one pin per chip selecting NTSC or PAL operation.[50]

Images may be output at 256 or 512 pixels horizontal resolution and 224, 239, 448, or 478 pixels vertically. Vertical resolutions of 224 or 239 are usually output in progressive scan, while 448 and 478 resolutions are interlaced. Colors are chosen from the 15-bit RGB color space, for a total of 32,768 possible colors. Graphics consist of up to 128 sprites and up to 4 background layers, all made up of combinations of 8x8 pixel tiles. Most graphics use palettes stored in CGRAM, with color 0 of any palette representing transparency.[50]

Sprites can be 8x8, 16x16, 32x32, or 64x64 pixels, each using one of eight 16-color palettes and tiles from one of two blocks of 256 in VRAM. Sprites may be flipped horizontally and vertically as a whole. Up to 32 sprites and 34 8x8 sprite tiles may appear on any one line; exceeding these limits causes excess sprites or tiles to be dropped. Each sprite lies on one of 4 planes, however a lower-numbered sprite will always cover a higher-numbered sprite even if the latter is on a higher priority plane. This quirk is often used for complex clipping effects.[50]

Background layers in most modes range from 32x32 to 128x128 tiles, with each tile on one of two planes ("foreground" and "background") and using one of 8 palettes. Tiles are taken from a per-layer set of up to 1024 (as VRAM permits) and can be flipped horizontally and vertically. Each layer may be scrolled both horizontally and vertically. The number of background layers and the size of the palettes depends on the mode:[50]

  • Mode 0: 4 layers, all using 4-color palettes. Each BG uses its own section of the SNES palette.
  • Mode 1: 3 layers, two using 16-color palettes and one using 4-color palettes.
  • Mode 2: 2 layers, both using 16-color palettes. Each tile can be individually scrolled.
  • Mode 3: 2 layers, one using the full 256-color palette and one using 16-color palettes. The 256-color layer can also directly specify colors from an 11-bit (RGB443) colorspace.
  • Mode 4: 2 layers, one using the full 256-color palette and one using 4-color palettes. The 256-color layer can directly specify colors, and each tile can be individually scrolled.
  • Mode 5: 2 layers, one using 16-color palettes and one using 4-color palettes. Tile decoding is altered to facilitate use of the 512-width and interlaced resolutions.
  • Mode 6: 1 layer, using 16-color palettes. Tile decoding is as in Mode 5, and each tile can be individually scrolled.
A typical Mode 7 screen
A typical Mode 7 screen
  • Mode 7: 1 layer of 128x128 tiles from a set of 256, which may be interpreted as a 256-color one-plane layer or a 128-color two-plane layer. The layer may be rotated and scaled using matrix transformations. HDMA is often used to change the matrix parameters for each scanline to generate perspective effects.

Background layers may be individually pixelized, and layers and sprites can be individually clipped and combined by color addition or subtraction to generate more complex effects and greater color depths than can be specified directly.[50]

The PPU may be instructed to latch the current pixel position at any time during image output, both by game software and by the device attached to controller port 2. The game software may then read back this latched position. The PPU may also be used for fast 16-bit by 8-bit signed multiplication.[50]

[edit] Audio

Audio reference
Processors Sony SPC700, Sony DSP
Clock Rates Input: 24.576 MHz
SPC700: 1.024 MHz
Format 16-bit ADPCM, 8 channels
Output 32 kHz 16-bit stereo
Effects
  • ADSR envelope control
  • Frequency scaling and modulation using Gaussian interpolation
  • Echo: 8-tap FIR filter, with up to .24s delay
  • Noise generation

The audio subsystem consists of an 8-bit Sony SPC700, a 16-bit DSP, 64 KB (KiB) of SRAM shared by the two chips, and a 64 byte boot ROM. The audio subsystem is almost completely independent from the rest of the system: it is clocked at a nominal 24.576 MHz in both NTSC and PAL systems, and can only communicate with the CPU via 4 registers on Bus B.[51][52]

RAM is accessed at 3.072 MHz, with accesses multiplexed between the SPC700 (13) and the DSP (23). This RAM is used to store the SPC700 program and stack, the audio sample data and pointer table, and the DSP's echo buffer.[51]

The SPC700 runs programs (uploaded using the boot ROM program) to accept instructions and data from the CPU and to manipulate the DSP registers to generate the appropriate music and sound effects. The DSP generates a 16-bit waveform at 32 kHz by mixing input from 8 independent voices and an 8-tap FIR filter typically used for reverberation. Each voice can play its PCM sample at a variable rate, with Gaussian interpolation, stereo panning, and ADSR, linear, non-linear, or direct volume envelope adjustment. The voice and FIR filter outputs are mixed both for direct output and for future input into the FIR filter. All audio samples are ADPCM compressed using Bit Rate Reduction.[51]

Hardware on the cartridge, expansion port, or both can provide stereo audio data for mixing into the DSP's analog audio output before it leaves the console.[53]

Since the audio subsystem is mostly self-contained, the state of the audio subsystem can be saved as an .SPC file, and the subsystem can be emulated in a stand-alone manner to play back all game music (except for a few games that constantly stream their samples from ROM).

[edit] Onboard RAM

Memory reference
Main RAM 128 KB
Video RAM 64 KB main RAM
512 + 32 bytes sprite RAM
256 × 15 bits palette RAM
Audio RAM 64 KB

The console contains 128 KB of DRAM. This is mapped to various segments of Bus A, and can also be accessed in a serial fashion via registers on Bus B. The video and audio subsystems contain additional RAM reserved for use by those processors.[50]

[edit] Regional lockout

Nintendo employed several types of regional lockout, including both physical and hardware incompatibilities.

A cartridge shape comparisonTop: Japanese and PAL designBottom: North American designThe top image also illustrates the optional pins used by enhancement chips.
A cartridge shape comparison
Top: Japanese and PAL design
Bottom: North American design

The top image also illustrates the optional pins used by enhancement chips.

On a physical level, the cartridges are shaped differently for different regions. North American cartridges have a rectangular bottom with inset grooves matching protruding tabs in the console, while other regions' cartridges are narrower with a smooth curve on the front and no grooves. The physical incompatibility can be overcome with use of various adapters, or through modification of the console.[54]

Internally, a regional lockout chip (CIC) within the console and in each cartridge prevents PAL region games from being played on Japanese or North American consoles and vice versa. The Japanese and North American machines have the same region chip. The console CIC releases the reset signal to the rest of the system only after completing a handshake with the chip in the cartridge.[54] This can be overcome through the use of adapters, typically by inserting the imported cartridge in one slot and a cartridge with the correct region chip in a second slot. Alternatively, disconnecting one pin of the console's lockout chip will prevent it from locking the console; hardware in later games can detect this situation, so it later became common to install a switch to reconnect the lockout chip as needed.[55]

PAL consoles face another incompatibility when playing out-of-region cartridges: the NTSC video standard specifies video at 60 Hz while PAL operates at 50 Hz, resulting in approximately 16.7% slower gameplay. Additionally, PAL's higher resolution results in letterboxing of the output image. Some commercial PAL region releases exhibit this same problem and therefore can be played in NTSC systems without issue, while others will face a 20% speedup if played in an NTSC console. To mostly correct this issue, a switch can be added to place the SNES PPU into a 60 Hz mode supported by most PAL televisions. Later games will detect this setting and refuse to run, requiring the switch to be thrown only after the check completes.[56]

[edit] Casing

Original Japanese SNES This image is a candidate for speedy deletion. It may be deleted after Tuesday, 1 April 2008.
Original U.S. SNES
Original PAL SNES
Super Famicom Jr.
Original Japanese version Original North American version Original PAL version Super Famicom Jr.

All versions of the SNES are predominantly gray, although the exact shade may differ. The original North American version has a boxy design with purple sliding switches and a dark gray eject lever. The Japanese and European versions are more rounded, with darker gray accents and buttons. The North American SNES 2 and the Japanese Super Famicom Jr. are both smaller with a rounded contour, however the SNES 2 buttons are purple where the Super Famicom Jr. buttons are gray.

All versions incorporate a top-loading slot for game cartridges, although the shape of the slot differs between regions to match the different shapes of the cartridges. The card-edge connector has 62 pads, however many cartridges only connect to the middle 46. All versions also incorporate two 7-pin controller ports on the front of the unit, and a plug for a power supply and a Nintendo-proprietary "multi-out" A/V connector on the back.[53] The multi-out connector, later used on the Nintendo 64 and GameCube, can output RF, RGB, S-Video, and composite video signals.[54] Original versions additionally include a 28-pin expansion port under a small cover on the bottom of the unit[53] and a standard RF output with channel selection switch on the back; newer versions use the RF capability of the multi-out connector.

[edit] Game cartridge

While the SNES can address 128 Mb (Mib), only 117.75 Mb are actually available for cartridge use. A fairly normal mapping could easily address up to 95 Mb of ROM data (48 Mb at FastROM speed) with 8 Mb of battery-backed RAM.[49] However, most available memory access controllers only support mappings of up to 32 Mb. The largest games released (Star Ocean and Tales of Phantasia) contain 48 Mb of ROM data, while smallest games contain only 2 Mb.

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.

[edit] Peripherals

The European and Australasian SNES controller
The European and Australasian SNES controller

The SNES standard controller adds two additional face buttons to the design of the NES iteration, arranging the four in a diamond shape, and the layout adds two shoulder buttons. It also features an ergonomic design later used for the NES 2. The Japanese and PAL region versions incorporate the system's logo in the colors of the four action buttons, while the North American version colors them lavender and purple to match the redesigned console. The North American version also differs in that the X and Y buttons are concave while the A and B buttons are convex (like PAL and JP region controller face buttons). Many believe that several later consoles derive their controller design from the SNES, including the PlayStation, PS2, PS3, Dreamcast, Xbox, Xbox 360, and Wii (Classic Controller).[57][58][59][60][61][62]

Throughout the course of its life, a number of peripherals were released which added to the functionality of the SNES. Many of these devices were modeled after earlier add-ons for the NES: the Super Scope is a light gun functionally similar to the NES Zapper (though the Super Scope features wireless capabilities) and the Super Advantage is an arcade-style joystick with adjustable turbo settings akin to the NES Advantage. Nintendo also released the SNES Mouse in conjunction with its Mario Paint title. Hudson Soft, under license from Nintendo, released the Super Multitap, a multiplayer adapter for use with its popular series of Bomberman games. Some of the more unusual controllers include the one-handed ASCII Stick L5, the BatterUP baseball bat, and the TeeV Golf golf club.[63]

While Nintendo never released an adapter for playing NES games on the SNES, the Super Game Boy adapter cartridge allows games designed for Nintendo's portable Game Boy system to be played on the SNES. The Super Game Boy touted several feature enhancements over the Game Boy, including palette substitution, custom screen borders, and (for specially enhanced games) access to the SNES console.[64]

Like the NES before it, the SNES saw its fair share of unlicensed third-party peripherals, including a new version of the Game Genie cheat cartridge designed for use with SNES games and a variety of game copier devices. In general, Nintendo proved to be somewhat more tolerant of unlicensed SNES peripherals than they had been with NES peripherals.

Soon after the release of the SNES, companies began marketing backup devices such as the Super Wildcard, Super Pro Fighter Q, and Game Doctor.[65] These devices were sold to create a backup of a cartridge, in the event that it would break. However, they could also be used to play copied ROM images that could be downloaded from BBSes and the Internet, or to create copies of rented video games, often violating copyright laws in many jurisdictions.

Satellaview with Super Famicom.
Satellaview with Super Famicom.

Japan saw the release of the Satellaview, a modem which attached to the Super Famicom's expansion port and connected to the St. GIGA satellite radio station. Users of the Satellaview could download gaming news and specially designed games, which were frequently either remakes of or sequels to older Famicom titles, released in installments. Satellaview signals were broadcast from April 23, 1995 through June 30, 2000.[66] In the United States, the similar but relatively short-lived XBAND allowed users to connect to a network via a dial-up modem to compete against other players around the country.

During the SNES's life, Nintendo contracted with two different companies to develop a CD-ROM-based peripheral for the console to compete with Sega's CD-ROM based addon, Sega CD. Ultimately, negotiations with both Sony and Philips fell through, and Sony went on to develop its own console based on its initial dealings with Nintendo (the PlayStation), with Philips gaining the right to release a series of titles based on Nintendo franchises for its CD-i multimedia player.[67]

[edit] Enhancement chips

Star Fox, the first game to utilize the Super FX chip, as shown with the polygonal models that compose a large portion of the game's graphics
Star Fox, the first game to utilize the Super FX chip, as shown with the polygonal models that compose a large portion of the game's graphics

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. This is most often characterized by 16 additional pins on the cartridge card edge.[53]

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.[35]

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.[68] 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 most often used; the DSP-2, DSP-3, and DSP-4 were used in only one title each.[69]

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.[35]

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.[70]

Many cartridges contain other enhancement chips, most of which were created for use by a single company in a few titles;[69] the only limitations are the speed of the Super NES itself to transfer data from the chip and the current rating of the console.

[edit] Market share

As of March 31, 2006, 49.1 million Super NES units were sold worldwide, with 20 million of those units sold in the U.S. according to Nintendo.[1][2][71] Although it could not quite repeat the success of the NES, which sold 61.9 million units worldwide as of March 31, 2006,[72][2] the Super NES was the best-selling console of its era. The Mega Drive/Genesis came in second with 29 million sold worldwide,[73][74][75] and the TurboGrafx-16 was third with 10 million sold worldwide.[76]

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