The 360 "Arcade" version simply replaced the core.
"Microsoft officially announced a new version the Xbox 360 called the Xbox 360 Arcade. It's like the Core, except now it comes bundled with five arcade style games (Pac-Man, Boom Boom Rocket, Feeding Frenzy, Luxor 2, and Uno), a wireless controller, has an HDMI port, and a includes a 256MB memory card for $280. (But like the Core, there's still no hard drive.)
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