The Original Nintendo DSi Prototype Included Two DS Cartridge Slots

These days, the Nintendo DSi is fondly remembered as the middle child between the original Nintendo DS and its full-blown successor in the Nintendo 3DS. The system featured several key upgrades to the user experience over its predecessor, including a dual-camera system for taking photos, a built-in internet browser, a virtual marketplace for purchasing digital titles a la the now-shut-down Wii Shop Channel, and, of course, the killer app that was Flipnote. But while the DSi took some considerable leaps ahead of the DS' capabilities, not every change the system featured was an upgrade.

In exchange for its slimmer form factor, the DSi sacrificed the original DS' built-in second cartridge slot for playing Game Boy Advance games and completely eliminated its backward compatibility features. However, what some fans of the system may not know is that at one point early into development for the DSi, the system was actually planned to still have two cartridge slots — only, neither of them were for the GBA. Rather, the original plan was for the DSi to feature two separate DS cartridge slots on each unit.

In a 2009 Game Developers Conference panel, Nintendo DSi lead Masato Kuwahara spoke about several unrealized hardware ideas planned for various Nintendo handhelds during early development (via IGN). During the event, Kuwahara revealed pictures of a DSi prototype that featured two distinct DS cartridge slots on the back. According to Kuwahara, the system would have allowed players to insert two DS cartridges and easily swap between them.

Unfortunately, the prototype with the two slots was substantially larger than the team desired, and the feature proved to be an unpopular idea among Kuwahara's colleagues. "It was as bad as I had feared," Kuwahara said during a 2009 talk with other Nintendo executives (via Eurogamer). "We hastily rethought it, decided to remove a certain specification [one of the DS slots], and started over, heading toward the form it has today."

While the DSi's cartridge quick-swapping didn't make the final cut, the system did end up being the first Nintendo handheld that allowed users to switch out a cartridge for a different one without powering down the system. Players could also quickly swap between digital DSiWare games for what that's worth.

As it stands, no mainstream system past the DSi has implemented a dual-slot system. And It's looking less likely to happen, as systems like the PlayStation 5 Digital Edition eschew physical slots entirely. Still, perhaps some bold modder can someday add the feature and make the DSi developers' dreams a reality.