# Super NES CD-ROM

The Super NES CD-ROM (commonly abbreviated to SNES CD) is an unreleased add-on for the Super Nintendo Entertainment System (SNES) video game console. It was built upon the functionality of the cartridge-based SNES by adding support for the CD-ROM format.
There were going to be two devices that would incorporate CD-ROM technology with the SNES, both were under development simultaneously. One device was to be an official Nintendo add-on device that connected the SNES via its expansion port. The other device was to be stand-alone console developed by Sony called the PlayStation would use their own CD-ROM format known as the "Super Disc" and would include compatibility with SNES cartridges.
The Sony PlayStation was developed in a joint venture between Nintendo and Sony and was publicly announced in 1990. A separate partnership with Philips led to the development of a CD-ROM/XA format add-on for SNES, and separately yielded a few Nintendo-themed games on the CD-i format. Eventually the three companies agreed on a common CD standard. The project moved to a 32-bit system and specifications were completed near end 1992, but by the summer of 1993, Nintendo quietly canceled the addon entirely.

## History

Sony engineer Ken Kutaragi became interested in working with video games after seeing his daughter play games on Nintendo's Famicom video game console. He took on a contract at Sony for developing the S-SMP audio chip of Nintendo's next console, the Super NES. Kutaragi secretly developed the chip, the Sony SPC 700. Sony was uninterested in the video game business, so most of his superiors did not approve of the project, but Kutaragi found support in Sony executive Norio Ohga and the project was allowed to continue. The success of the project spurred Kutaragi, who believed CD-ROMs would overtake cartridges, to propose a CD-ROM drive for the Super NES. Nintendo disagreed, believing that CD-ROMs were too slow, but agreed to allow Sony to design the add-on after Kutaragi claimed the drive would be used for everything but games. The result of the deal would be a CD-ROM add-on for the Super NES as well as a Sony-branded console called PlayStation that would play both Super NES cartridges and Super Disc games.
Development of the format started in late 1988, when Nintendo signed the contract with Sony. The system was to be compatible with existing Super NES cartridges and with games released for the Super Disc format. Under their agreement, Sony would develop and retain control over the Super Disc format, with Nintendo thus effectively ceding a large amount of control of software licensing to Sony. Further, Sony would also be the sole benefactor of licensing related to music and movies software that it had been aggressively pursuing as a secondary application. Nintendo president Hiroshi Yamauchi was already wary of Sony at this point and deemed it unacceptable, because Sony was the sole provider of the S-SMP audio chip in the SNES and required developers to buy its expensive and proprietary audio development tool. Nintendo had become suspicious of Sony's growth, because of the combination of the audio chip, Sony's PlayStation hybrid console, and Sony's rapid expansion beyond its electronics origins into music, movies, and most recently software. Nintendo suspected that it had become a prop in Sony's console ambitions.
Furthermore, Yamauchi started to see a more favorable partner in Philips, one of Sony's largest competitors. To counter the proposed agreement, Yamauchi sent Nintendo of America president Minoru Arakawa and executive Howard Lincoln to the Netherlands to negotiate a more favorable contract with Philips. As David Sheff said in his book Game Over, "[The Philips deal] was meant to do two things at once: give Nintendo back its stranglehold on software and gracefully f--k Sony." At the June 1991 Consumer Electronics Show, Sony announced its SNES-compatible console based on both cartridge and CD, called the PlayStation. The next day, Nintendo revealed its partnership with Philips at the show, which surprised the audience, including Sony.
While Nintendo and Sony attempted to resolve their differences, between two to three hundred prototypes of the PlayStation were produced, and software for the system was being developed. In 1992, a deal was reached allowing Sony to produce SNES-compatible hardware, with Nintendo retaining control and profit over the games. The organizations never repaired their rift afterwards, although Sony executives remained convinced that remaining with the more experienced Nintendo was the best course of action. By the next year, upon Kutaragi's suggestions, Sony had dropped further development of the Super NES CD-ROM to develop its own console for the next generation, the PlayStation.

## Sony PlayStation prototype

In July 2015, it was reported that one of the original Sony PlayStation prototypes had been found. The prototype was reportedly abandoned by former Sony Computer Entertainment CEO Ólafur Jóhann Ólafsson during his time at Advanta. A former Advanta worker, Terry Diebold, acquired the device as part of a lot during Advanta's 2009 bankruptcy auction. The system was later confirmed as operational and plays Super Famicom cartridges as well as its included test cartridge, although the audio output and CD drive were non-functional. The original power supply for the system was never received by Diebold during his time at Advanta, so he used a third-party power supply to power it. The prototype came with a Sony/PlayStation-branded version of the standard Super Famicom controller (model number SHVC-005).
Some groups have attempted to develop homebrew software for the console such as Super Boss Gaiden, as there were no known games to use the CD drive. In March 2016, retro-gaming website RetroCollect reported that it (and influential members of online emulation communities) had received (from an anonymous source) a functional disc boot ROM for the SNES CD.
Diebold had given the unit to hardware hacker Benjamin Heckendorn, to examine around 2016. He also posted a tear-down video of the system that same year. Heckendorn later identified faults in several on-board components which he subsequently replaced in 2017, resulting in fixing the audio and CD drive issues indirectly. Because the system never received its original power supply (Diebold never got the original one as mentioned above), Heckendorn created a custom power supply for the system using the original PlayStation's power supply along with replacing the original power connector of the system with the one from a Sony Walkman, to ensure that it would be powered on without the need for its original power supply. Heckendorn showed Super Famicom (and SNES games via an adapter) working on the system and also showed audio CDs working on the system as there were no known game CDs, but affirmed that homebrew games worked.
The prototype was auctioned by Diebold in February 2020, with an initial price of US$15,000, but the auction quickly exceeded $350,000 within two days. It was sold for $360,000 to Greg McLemore, an entrepreneur and founder of Pets.com, who has a large collection of other video game hardware and plans to establish a permanent museum for this type of hardware.

### Technical specifications

Heckendorn's July 2016 teardown video also provides some technical specifications of the prototype. The standalone unit features two Super NES controller ports, a cartridge slot, a dual-speed CD-ROM drive, RCA composite jacks, S-Video, RFU DC OUT (similar to the PlayStation SCPH-1001), a proprietary multi-out AV output port (the same one featured on the Super NES, Nintendo 64, and GameCube), headphone jack on the front, a serial port labelled "NEXT" (probably for debugging), and one expansion port under the unit. Heckendorn said the system would have probably been as powerful as a standard Super NES, but not as powerful as the Sega CD.
The specifications of the Sony PlayStation prototype are different from that of the proposed add-on by Philips, which were published in the March 1993 edition of Electronic Gaming Monthly (EGM).
| System | PC Engine CD-ROM² | Sega CD | SNES CD (SFX-100) | SNES CD (Add-on; Philips) (EGM 1993) |
| CPU (MHz) | 7.16 | 7.67 | 3.58 | 3.58 |
| Co-CPU (MHz) | None | 4 | 2.048 | 2.048 |
| Bus Width (Bits) | 8 | 16 | 8 | 8 |
| Add-on Processor (MHz) | None | 12.5 | None | 21 (NEC V810; 32-bit RISC) |
| Add-on Video | None | Present | None | None |
| Add-on Audio | CD | ASIC+CD (Ricoh PCM+CDDA) | CD | CD (CD-ROM XA) |
| CD-ROM Speed | 1x | 1x | 2x | 1x / 2x |
| Main RAM (KB) | 8 | 64 | 128 | 128 |
| Video RAM (KB) | 64 | 64 | 64 | 64 |
| Audio RAM (KB) | 0 | 8 | 64 | 64 |
| Exp RAM (KB) | 64 (256 with Super CD and 2048 with Arcade Card) | 512 | 256 | 512 / 1024 |
| Exp Video RAM (KB) | 0 | 256 | 0 | 0 |
| Exp Audio RAM (KB) | 64 | 64 | 0 | 0 |
| CD Cache RAM (KB) | 0 | 16 | 32 | 128 |
| Backup RAM (KB) for save data | 0 | 8 | 8 | 8 |
| Total RAM (KB) | 200 (392 with Super CD, 2184 with Arcade Card) | 992 | 552 | 904 / 1416 |

## Legacy

After the original contract with Sony failed, Nintendo continued its partnership with Philips. This contract provisioned Philips with the right to feature Nintendo's characters in a few games for its CD-i multimedia device, but never resulted in a CD-ROM add-on for the SNES. The Nintendo-themed CD-i games were very poorly received, and the CD-i is considered a commercial failure. The Nintendo-themed CD-i games would become popular on the internet years later. Sony would then pursue their ambitions to launch their own video game console and continued to develop the PlayStation, dropping compatibility with the SNES. They even entered a short-lived alliance with Sega, where it was agreed that both companies would share all costs and risk for the new CD-ROM drive, and ultimately the next generation console. Ultimately, Sega canceled the partnership, claiming that Sony knew little of the industry at the time. Sega then resumed development of what would eventually become the Sega Saturn.
The main game in development for the SNES CD platform launch was Square's Secret of Mana, whose planned content was cut down to the size suitable for cartridge and released on that medium instead. A tentative reconciliation in late 1992 gave better terms to Nintendo for game royalties while allowing Sony royalties for all other software and the rights to produce SNES-compatible hardware, such as the PlayStation. This resulted in more powerful hardware specifications. Kutaragi however became emboldened enough from his experiences working with Nintendo and Sega that Sony could go it alone from scratch, and broke away from Nintendo to develop their own next generation console.
Sony released the PlayStation in December 1994 in Japan and September 1995 in North America and Europe, and would go on to become a global success. This new next-generation CD-based console successfully competed with Nintendo's cartridge-based Nintendo 64 as well as other CD-based consoles such as the Fujitsu FM Towns Marty, the NEC PC-FX, the SNK Neo Geo CD, the Panasonic 3DO, and the Sega Saturn, making it a console leader. Sony would become a significant player in the video game industry, establishing the PlayStation brand which continues to this day. The broken partnership with Sony has often been cited as a mistake by Nintendo, effectively creating a formidable rival in the video game market as a consequence of Sony's and Kutaragi's shrewd determination to break into the market. It has also been argued that if Nintendo had never broken the deal, its position may have been further undermined by Sony. Nintendo, still convinced of the faster load times and stronger anti-piracy of the cartridge, did not release an optical disc-based console until the GameCube in 2001.