Rumble Pak
Rumble Pak Detailed Specs

You've seen and heard the power of the Nintendo 64, now you can actually feel it! With the release of Star Fox 64 in June 1997, Nintendo introduced the Rumble Pak, a device that physically responds to the action in compatible games, immersing you in the game play. You've got to feel it to believe it!
  
A Force-Feedback First  
    
The Rumble Pak creates different degrees of vibrations, depending on the actions on-screen.  The Rumble Pak is the first home video-game controller accessory to create a physical sensation that complements the on-screen action. When connected to the Nintendo 64 Controller, the Rumble Pak creates different degrees of vibrations, depending on the actions on-screen. The unit vibration increases when a large explosion is experienced, e.g., after defeating a level boss. With Star Fox 64, the unit creates various short vibrations when players use the turbo boost, brake, hit the ground or a wall, or are hit by enemy fire. 

How It Works   
    
N64 sends signals to the Rumble Pak, activating the motor according to the action's intensity.  The Rumble Pak unit contains a small, vibrating motor, similar to those used in pagers. When the on-screen action heats up, the N64 sends signals to the Rumble Pak, activating the motor according to the action's intensity. Powered by two AAA batteries (included), the unit delivers approximately 50-60 hours of rumbling action.
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