Watch a video of this rare U.S. Nintendo 64DD prototype

Back in the 1990s, console manufacturers like Nintendo and Sega thought expanding the capabilities of their home gaming systems with add-on hardware was a great idea (like the Genesis’s 32X or CD expansion). Nintendo, however, changed its opinion before releasing one of its more interesting products in the United States.
The Nintendo 64DD, also known as the 64 Disk Drive, never came out in the U.S., but someone has found a prototype unit that proves the company was well into testing the ha