Up for sale is a Nintendo 64DD prototype disk. The disk was tested and was found to be blank. Since it was blank, a dev unit was used to download Mario 64 disk version onto it. It contains a certain code in the coding of the game which is there to prove that this is not the Mario 64 prototype. The code doesn't affect the game. 

This disk will look great in a collection or for someone who may own a dev unit.

Message me for any questions.

I usually ship within 2 days of a payment.