Switch Online is Nintendo’s first paid online gaming service, right? Nope. In 1999, Nintendo added the Internet to its Nintendo 64 hardware, by way of a disk drive add-on called the 64DD. It’s one of the company’s most interesting failures.

Yes, it’s time once again for Complete In Box, our show that takes a look back at classic games by examining not only the software, but all the physical stuff that came with it. Today’s a special episode—we’re not just looking at one game, but a piece of hardware and its entire library.

By using magnetic disks that stored 64 MB of writeable data, the 64DD was supposed to usher in a new era of creative play, with games like Mario Artist and SimCity 64. It could also connect to the Internet so you could share your creations and compete with others. But even though Nintendo hyped it up for years, it only ended up releasing in Japan, sold only about 15,000 units, and was quickly discontinued.

It’s now a sought-after collectible and a unique piece of the company’s long, long history of bold experimentation.