The Nintendo DS (Dual Screen), designed and manufactured by Nintendo, is a portable game console with two screens. It is a seventh generation console released on November 21st, 2004, in the USA. The top screen is primarily used for action sequences, while the touchable screen below it is used for carrying out actions. Along with new games, the DS allows people to play games for the Game Boy Advance. Over 125.13 million units (including the DS Lite and DSi) have been sold nationwide. A wand is available to touch the touch screen. On the back of the DS there is a slot to keep the wand safe. Other items, like a pen or finger, can be used for the touch screen. The graphics range from 8-bit, to 64 in certain games.
Before the DS, a similar Nintendo console with two screens was released called, Game & Watch. There was a series of multi-screens, and Nintendo reused the design for the DS. Since it's release there have been many new versions of the DS released: DS Light, Nintendo DSi, Nintendo DSi XL, and a new version coming out that will allow players to play in a 3D environment without goggles.
Like the Game Boy, the DS comes with a control pad, and A, B, Y, X, L, and R buttons. The dual screens are a different feature. The top screen cannot be touch, and functions like a normal screen. The touch screen has different uses in different games, but mostly relies on tapping and dragging motions of a wand. Another creative device is the microphone. Like in the game Nintendogs, the microphone can recognize a human voice. In a game called Trace Memory, I was required to blow into the microphone to wipe off dust from an old painting.
The wand can be considered external, since it's not always required to play a DS game. A Wi-Fi USB connector can be bought separately and used to connect certain games, and even chat with other people on the internet (may be limited in certain games and DS features). Game Boy Advance games can be played on the first DS, on the DS Light the Game Boy Advance cartridge stuck out awkwardly, and the DSi the GBA slot was eliminated. Newer DS consoles have more sophisticated technology. The DS also comes with a battery charger.
The DS is currently the only console with a double screen with 'touchable' features. Most games have been aimed at a younger audience, allowing people of all ages to enjoy the DS. The DS comes in many colors, some limited edition.
Currently Pokemon is popular (again), but Nintendogs was the DS' first major hit, followed by Zelda and Mario titles.
http://www.bit-tech.net/news/gaming/2010/03/23/nintendo-announces-new-3d-ds/1
http://www.nintendodsi.com/#slideshow=dsiware
http://www.gamefly.com/RentalMediaTitleSearch/Browse/?pf=1060&cat=MostPopular
http://en.wikipedia.org/wiki/Nintendo_DS