Super NES

{{#invoke:Category handler|main}} {{#invoke:Infobox|infobox}} The Super Nintendo Entertainment System (also known as the Super NES, SNESTemplate:Refn or Super Nintendo) is a 16-bit home video game console developed by Nintendo that was released in 1990 in Japan, 1991 in North America, 1992 in Europe and Australasia (Oceania), and 1993 in South America. In Japan, the system is called the Template:Nihongo, or SFC for short. In South Korea, it is known as the Super Comboy (슈퍼 컴보이 Syupeo Keomboi) and was distributed by Hyundai Electronics. Although each version is essentially the same, several forms of regional lockout prevent the different versions from being compatible with one another.

The Super Nintendo Entertainment System is Nintendo's second home console, following the Nintendo Entertainment System (NES). The console introduced advanced graphics and sound capabilities compared with other consoles at the time. Additionally, development of a variety of enhancement chips (which were integrated on game circuit boards) 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 and Europe from Sega's Genesis/Mega Drive console. The SNES remained popular well into the 32-bit era, and continues to be popular among fans, collectors, retro gamers, and emulation enthusiasts, some of whom are still making homebrew ROM images.

History

File:Super NES designs.png

Early concept designs for the SNES, referred to as the "Nintendo Entertainment System 2".

To compete with the popular NES/Famicom, NEC launched the TurboGrafx-16 in 1987, and Sega followed suit with the Sega 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, it took several years for Sega's system to become successful.<ref>Sheff (1993), pp. 353–356. "The Genesis continued to flounder through its first couple of years on the market, although Sega showed Sisyphean resolve.... [By mid-1991] Sega had established itself as the market leader of the next generation."</ref> Nintendo executives were in no rush to design a new system, but they reconsidered when they began to see their dominance in the market slipping.<ref>Kent (2001), pp. 413–414.</ref>

Launch

File:Super Famicom logo.svg

The four color Super Famicom mark was also used as part of the Super NES logo in the PAL region. They correspond to the colors of the ABXY buttons of the control pad in those regions.

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.<ref>Kent (2001), pp. 422–431.</ref> The system's release also gained the attention of the Yakuza, leading to a decision to ship the devices at night to avoid robbery.<ref>Sheff (1993), pp. 360–361.</ref>

With the Super Famicom quickly outselling its chief rivals, Nintendo reasserted itself as the leader of the Japanese console market.<ref>Kent (2001), pp. 431–433. "Japan remained loyal to Nintendo, ignoring both Sega's Mega-Drive and NEC's PC Engine (the Japanese name for TurboGrafx).... Unlike the Japanese launch in which Super Famicom had outsold both competitors combined in presales alone, SNES would debut against an established product."</ref> 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, Koei, and Enix.<ref>Template:Cite web</ref>

File:Supermarioworld map.PNG

"Nintendo's strongest selling point, however, was the game that came packed in with the SNES console—Super Mario World."<ref name="Kent 432">Kent (2001), p. 432. Kent states September 1 was planned but later rescheduled to September 9.</ref>

On August 23, 1991,Template:Refn 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. Most of the PAL region versions of the console use the Japanese Super Famicom design, except for labeling and the length of the joypad leads. The Playtronic Super Nintendo in Brazil, although PAL, uses the North American design.<ref>Template:Cite web</ref> Both the NES and SNES were released in Brazil in 1993 by Playtronic, a joint venture between the toy company Estrela and consumer electronics company Gradiente.<ref>Template:Cite web</ref>

The SNES and Super Famicom launched with 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.<ref>Sheff (1993), p. 361.</ref> In North America, Super Mario World launched as a bundle with the console, and other launch titles include F-Zero, Pilotwings (both of which demonstrated the console's "Mode 7" pseudo-3D rendering capability), SimCity, and Gradius III.<ref>Template:Cite web</ref>

Technical specifications

Template:Main The 16-bit design of the SNES<ref>Template:Cite web</ref> incorporates powerful graphics and sound co-processors that allow tiling and simulated 3D effects, a palette of 32,768 colors, and high-quality 8-channel audio. These base platform features, plus the ability to dramatically extend them all through substantial chip upgrades inside of each cartridge, represent a leap over the 8-bit NES generation and some significant advantages over the competition such as the Sega Genesis.<ref>Template:Cite web</ref>

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 on 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.<ref name="anomie_memmap">Template:Cite web</ref>

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).<ref name="anomie_memmap"/> 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.<ref group="lower-alpha">This quantity uses the standard decimal meaning of megabyte: 1,000,000 bytes.</ref><ref name="anomie_regs">Template:Cite web</ref>Template:Unreliable source?

The DMA unit has 8 independent channels, each of which can be used in two modes. General DMA transfers up to 64 kB<ref group="lower-alpha" name="binary prefix">Unless otherwise specified, kilobyte (kB), megabyte (MB), and megabit (Mbit) are used in the binary sense in this article, referring to quantities of 1024 or 1,048,576.</ref> 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.<ref name="anomie_regs"/>

The 5A22 also contains an 8-bit parallel I/O port (which is 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.<ref name="anomie_regs"/> Template:-

Video

Video reference
Resolutions	Progressive: 256×224, 512×224, 256×239, 512×239 Interlaced: 512×448, 512×478
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 64 × 64 pixels
Backgrounds	Up to 4 planes; each up to 1024 × 1024 pixels
Effects	Pixelization (mosaic) per background Color addition and subtraction Clipping windows (per background, affecting color, math, or both) Scrolling per 8 × 8 tile Mode 7 matrix operations

The graphics processing unit (GPU) consists of two separate but closely tied IC packages, which may be considered as a single entity. It also contains 64 kB<ref group="lower-alpha" name="binary prefix"/> of SRAM for storing video data (VRAM), 544 bytes of object attribute memory (OAM) for storing sprite data, and 256 × 15 bits of color generator RAM (CGRAM) for storing palette data. The VRAM is actually divided into two 32 kB sections with separate address and data buses, essentially for the necessary access patterns used by BG Mode 7. The GPU 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 GPU chips, with one pin per chip selecting NTSC or PAL operation.<ref name="anomie_regs"/>

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 8×8 pixel tiles. Most graphics use palettes stored in CGRAM, with color 0 of any palette representing transparency.<ref name="anomie_regs"/>

Sprites can be 8 × 8, 16 × 16, 32 × 32, or 64 × 64 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 8 × 8 sprite tiles may appear on any one line; excess sprites or tiles would 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.<ref name="anomie_regs"/>

Background layers in most modes range from 32 x 32 to 64 × 64 tiles, each of size 8 x 8 or 16 x 16 pixels, 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:<ref name="anomie_regs"/><ref>Template:Cite web</ref>

• Mode 0: 4 layers, all using 4-color palettes. Each BG uses its own section of the SNES palette. Up to 96 colors can be displayed on the backgrounds, 24 colors per layer.
• Mode 1: 3 layers, two using 16-color palettes and one using 4-color palettes. Up to 120 colors can be displayed by first two layers and 24 colors by third layer.
• Mode 2: 2 layers, both using 16-color palettes. Each tile can be individually scrolled. Up to 120 colors can be displayed on screen.
• 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. Up to 256 colors displayed by first layer and 120 colors by second layer.
• 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. Up to 256 colors displayed by first layer and 24 colors by second layer.
• 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. Up to 120 colors displayed by first layer and 24 colors by second layer.
• Mode 6: 1 layer, using 16-color palettes. Tile decoding is as in Mode 5, and each tile can be individually scrolled. Up to 120 colors can be displayed on screen.

File:Mode 7 Test-0000.png

A test image demonstrating the SNES's Mode 7 capability

• Mode 7: 1 layer of 128×128 tiles of size 8x8 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.<ref name="anomie_regs"/>

The GPU 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 GPU may also be used for fast 16-bit by 8-bit signed multiplication.<ref name="anomie_regs"/>

Audio

Audio reference
Processors	Nintendo S-SMP
Clock rates	Input: 24.576 MHz SPC700: 1.024 MHz
Format	8 channel ADPCM
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<ref group="lower-alpha" name="binary prefix"/> 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.<ref name="anomie_apudsp">Template:Cite web</ref>Template:Unreliable source?<ref name="anomie_spc700">Template:Cite web</ref>Template:Unreliable source?

RAM is accessed at 3.072 MHz, with accesses multiplexed between the SPC700 (Template:Fraction) and the DSP (Template:Fraction). This RAM is used to store the SPC700 program and stack, the audio sample data and pointer table, and the DSP's echo buffer.<ref name="anomie_apudsp"/> 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 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 compressed using ADPCM and a linear predictive coding, a method dubbed BRR.<ref name="anomie_apudsp"/>

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.<ref name="anomie_ports"/> Since the audio subsystem is mostly self-contained, the state of the audio subsystem can be connected to, or emulated on, a host computer. Its output may be saved as an SPC700 sound format (.SPC) file, or the audio 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. Custom cartridges or PC interfaces can be used to load and play .SPC files onto a real SNES SPC700 and DSP. Template:-

Onboard RAM

Memory reference
Main RAM	128 kB<ref group="lower-alpha" name="binary prefix"/>
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<ref group="lower-alpha" name="binary prefix"/> 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.<ref name="anomie_regs"/>

Regional lockout

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

File:SNES-SFAM-Cartridges.jpg

A cartridge shape comparison
Top: North American design
Bottom: Japanese and PAL region design.

---

The bottom cartridge also illustrates the optional pins used by enhancement chips such as the Super FX 3D chip.

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.Template:Citation needed

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.Template:Citation needed 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.<ref>Template:Cite web</ref>

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 newer PAL televisions. Later games will detect this setting and refuse to run, requiring the switch to be thrown only after the check completes.<ref name="SNES-pal-switch">Template:Cite web</ref> Template:-

Casing

Original Japanese SNES	Error creating thumbnail: File with dimensions greater than 12.5 MP Original U.S. SNES	Original PAL SNES Original PAL SNES	Super Famicom Jr. Super Famicom Jr.	Super Famicom Jr. Super Famicom Jr.
Original Japanese version (1990–1998)	Original North American version (1991–1997)	Original PAL version (1992–1998)	Super Famicom Jr. (1998–2003)	North American redesign (1997–1999)

All versions of the SNES are predominantly gray, although the exact shade may differ. The original North American version, designed by Nintendo of America industrial designer Lance Barr<ref name="NP25" /> (who previously redesigned the Famicom to become the NES<ref name="barr-interview">Template:Cite web</ref>), has a boxy design with purple sliding switches and a dark gray eject lever. The loading bay surface is curved, both to invite interaction and to prevent food or drinks from being placed on the console and spilling as had happened with the flat surfaced NES.<ref name="NP25">Template:Cite journal</ref> The Japanese and European versions are more rounded, with darker gray accents and buttons. The North American SNS-101 model and the Japanese Super Famicom Jr. (the SHVC-101 model), all designed by Barr, are both smaller with a rounded contour; however, the SNS-101 buttons are purple where the Super Famicom Jr. buttons are gray. The European and American versions of the SNES controllers have much longer cables compared to the Japanese Super Famicom controllers.

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 contacts; 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.<ref name="anomie_ports">Template:Cite web</ref>Template:Unreliable source? The MULTI OUT connector (later used on the Nintendo 64 and GameCube) can output composite video, S-Video and RGB signals, as well as RF with an external RF modulator.Template:Citation needed Original versions additionally include a 28-pin expansion port under a small cover on the bottom of the unit<ref name="anomie_ports"/> and a standard RF output with channel selection switch on the back;<ref>Template:Cite web</ref> the redesigned models output composite video only, requiring an external modulator for RF.<ref>Template:Cite web</ref>

File:Oxidized-snes.jpg

Yellowing of console plastic

The ABS plastic used in the casing of some older SNES and Super Famicom consoles is particularly susceptible to oxidization on exposure to air, likely due to an incorrect mixture of the stabilizing or flame retarding additives. This, along with the particularly light color of the original plastic, causes affected consoles to quickly become yellow; if the sections of the casing came from different batches of plastic, a "two-tone" effect results.<ref>Template:Cite web</ref> The color can sometimes be restored with UV light and a hydrogen peroxide solution.<ref>Template:Cite web</ref>