The 64DD was intended to be an expansion to Nintendo 64. The result was that the N64 would be able to use more memory and offer some exclusive games. It was briefly seen in Japan, but it never took off anywhere else. However, ASSEMbler forum user “PostedOval” has posted to images of what they claim to be a USA version of the 64DD. We’ve included both pictures below. It’s not quite definite yet that these are real, so we’ll keep you posted.