An emulator in computing duplicates (provides an emulation of) the functions of one system using a different system, so that the second system behaves like (and appears to be) the first system. This focus on exact reproduction of external behavior is in contrast to some other forms of computer simulation, which can concern an abstract model of the system being simulated.
3DO
Arcade
ATARI 2600
DreamCast
GameBoy Advance
NES
Nintendo 64
Nintendo DS
Nintendo Gamecube
Playstation
PlayStation 2
PlayStation 3
PlayStation Portable
SEGA Game Gear, Master System, Genesis/Mega Drive
SEGA Saturn
SNES
XBOX 360