http://www.screenagercentral.com/weeklyreader/break/stamper/ said:
The Stampers always believed that they could make great games given the chance, so they started their own company. During the mid-eighties, the Stampers designed popular games for the Sinclair Computer, a home computer that caught on better in Europe than the United States.
As the popularity of the Sinclair began to wane, Joel Hochberg, the Stampers' American partner, showed them a new game system that had recently hit the market in Japan. The system was the Famicom, the console that would later be released as the NES in the West. The Stampers were impressed and decided to ally themselves with Nintendo.
Unfortunately, Nintendo wasn't particularly interested in setting up partnerships with Western development companies at the time.
"We went to Mr. Arakawa and told him that we wanted to make games for Nintendo, and he said fine," says Chris Stamper. "Originally we went to him and asked for the technical specs, but we couldn't get those, so I reverse- engineered the NES. I understood coin-op hardware, so I had a good idea of what the Nintendo actually contained."
"We produced a demo. When Mr. Arakawa saw the demo, he said 'Okay, you have our blessings', and gave us the full specifications."
"I think Chris got it about 99% correct," says Tim Stamper. "There were just a few things we didn't know about. But the interesting thing was that there were things about the machine that Chris discovered that weren't documented that instantly gave us an advantage which other developers didn't have."
Among other things, Stamper discovered that the NES could play games in a split-screen mode. Prior to Rare's reinvention of the NES, nobody had looked into doing split-screen games. Other companies had made two-player games, but they were always single-screen games such as Contra, from Konami, and Double Dragon, from Trade West.
Rare's first NES game was Slalom, a somewhat forgettable skiing simulation. The company's second NES game, R.C. Pro Am, was mostly the work of Chris Stamper. It was the first NES game to feature split-screen competition. This radio-controlled car racing simulation is generally considered one of the best games of its time.
R.C. Pro Am was just one of more than 60 games that Rare developed for the NES. Though the Stampers preferred to run a small and anonymous operation through the eighties, they managed to develop games for Acclaim, Milton Bradley, and other better known companies. The NES versions of Wizards and Warriors, Jordan vs Bird, Marble Madness, and Battletoads were all Rare games.