The release of the Mega Drive and Turbografix-16 consoles in 1989 meant that Nintendo too had to come up with a 16-bit machine to stay in the game. It did not release the SNES in Japan until November 1990, known there as the Super Famicom, in the US in September 1991 and in the UK in April 1992, simply because the NES was doing well and new games were still being released for it. When it finally hit the market though, it proved to be a powerful and impressive competitor to Sega's Mega Drive and NEC's Turbografix-16.
The SNES had a much slower processor then the Mega Drive, but it really excelled when it came to its graphics processor. It could produce 32K colors, 256 of which could be displayed on screen at the same time, and had special hardware modes that allowed for effects such as scaling, rotating and transparency. This was the SNES's strong point.
Animation effects in games that involved scaling objects (i.e. zooming in and out of screen) or rotating them required lots of graphical sequences at a high frame rate that took up lots of space and processing power. The SNES's solution was to provide abstract hardware modes that a game could use in order to achieve effects like scaling, rotation and transparency. The famous Mode 7 was the hardware mode responsible for scaling and rotating.
In addition to its built-in hardware modes, Nintendo later released a whole array of chips that added processing power as well as other features to games. They came built into games' PCBs as opposed to plugging into the console's extension port. The Super FX chip, which allowed for 3D graphics to be rendered in games, upped the SNES's speed to 10.5MHz and the Super FX2 upped it to 21MHz. Many more chips were made available, and most of them played a large part in keeping the SNES competitive even in the face of the newer 32-bit consoles.
One thing Nintendo did differently this time round was they didn't force software developers to write games exclusively for them. Actually, this wasn't even an option for Nintendo because the major third-party software developers were already signed up with Sega. The move was a right one, and many quality games available for the Mega Drive got written for the SNES. Others, such as the arcade hit Street Fighter II, made their debut on the SNES. The censored version of Mortal Kombat was a bit embarrassing, but anyway...
Of course, there was that whole issue with Nintendo and Sony (and later on Philips) who were working on a CD add-on for the SNES. When Nintendo decided that loading times would plague games and broke the deal, Sony decided to start work on their own CD-based console, and we all know what happened next. More on this in the Playstation section.
The SNES retailed for $200 in the US and £150 in the UK. Over 46 million units were sold worldwide. The one pictured below is the European version. The US version has a completely different look. Much like Beauty and the Beast.