Here's the official press release right from Nintendo's E3 page.

IBM 400 MHz Copper Processor to Power Next Nintendo Game Machine

LOS ANGELES, CA (May 12, 1999) –IBM and Nintendo today announced a multi-year $1 billion technology agreement to support Nintendo’s next home video game console, code-named "Dolphin."

As part of the agreement, IBM will design and manufacture a unique 400 MHz central processor featuring IBM’s industry-leading 0.18 micron copper technology. The chip, dubbed the "Gecko" processor, is an extension of the IBM Power PC architecture. It’s designed to be more powerful than those found in any current or planned home video game entertainment system, providing players with dramatically better graphics and more realistic action. The processor is in the advanced stages of development, supporting Nintendo’s plans for a worldwide launch for the 2000 holiday season.

While the relationship initially involves the development and production of the copper-based processor, the companies will explore the potential use of IBM technology in other Nintendo products as well. The current arrangement calls for IBM to design, manufacture and ship copper processors to Nintendo, with the potential value of the deal exceeding $1 billion. "Dating from our very first home system in 1983, Nintendo’s ongoing commitment is to provide game developers with industry-leading technology to create new game experiences for our players," explains Howard Lincoln, chairman, Nintendo of America. "IBM’s new copper-based chip delivers on that commitment like never before, and we’ve jointly committed to a long-term relationship to assure revolutionary results."

In order to provide more power than Nintendo’s current game system chip, the IBM processor leverages IBM’s experience with complex system designs to incorporate enhancements specifically required by Nintendo. These include extra on-chip memory and more efficient data management between the processor and the game system’s primary graphics chip.

"As customers such as Nintendo develop increasingly sophisticated systems, the complexity of the chips that power them grows dramatically," says Dr. John Kelly, general manager, IBM Microeletronics Division. "Not many companies are able to meet this need. We have the technology, design expertise and manufacturing experience necessary to develop and deliver customized solutions for our customers."

With IBM’s advanced copper processor powering the next Nintendo system, developers can create game designs featuring the degree of realism, emotional connection, fantasy or interaction they’ve always imagined.

"Designing games is an ever-changing process, and this chip with its speed and seamless data flow, will allow us to make even more amazing games, " explains Chris Stamper, chairman and technical director of Rare, Ltd., producer of mega-hit games Goldeneye and Banjo-Kazooie for the N64. "Consumers will love the end result with the upcoming system."

"In my mind, I’d always envisioned what a game like Zelda could look like, and with the N64, I was able to create it," describes Shigeru Miyamoto, Nintendo developer and world-renowned game designer. "Now, with the Gekko processor, I can see an opportunity to take game designs to a new level."

The IBM copper processor will be paired with a revolutionary graphics chip designed by ArtX Inc., one of the world’s leading 3D graphics technologists located in Palo Alto, California. The ArtX team, led by chairman, Dr. Wei Yen, includes a number of well known 3D graphics designers. "The lineup of companies working on Nintendo’s next system is hugely exciting," notes Dr. Wei Yen. "The match between Nintendo’s know-how in the video game field, and the enormity of what IBM brings to the table can’t be matched."

The Nintendo game system processor chips will be manufactured at IBM’s high-volume manufacturing facility in Burlington, VT, where copper-based processors have been manufactured and shipped to customers since 1998.

Nintendo Co., Ltd., of Kyoto, Japan, is the acknowledged worldwide leader in the creation of interactive entertainment. To date, Nintendo has sold more than one billion video games worldwide, and has created such industry icons as Mario and Donkey Kong and franchises like The Legend of Zelda and Pokémon. Nintendo manufactures and markets hardware and software for its popular home video game systems, including the Nintendo 64 and the Game Boy – the world's best-selling video game system. As a wholly owned subsidiary, Nintendo of America Inc., based in Redmond, Wash., serves as headquarters for Nintendo's operations in North America.

IBM Microelectronics is a key contributor to IBM's role as the world’s premier information technology supplier. IBM Microelectronics develops, manufactures and markets state-of-the-art semiconductor technologies, products, packaging and services. Its superior integrated solutions can be found in many of the world’s best-known electronic brands. More information about IBM Microelectronics can be found at http://www.chips.ibm.com.