Hack the Dreamcast Visual Memory Unit

Play homebrew games on Dreamcast’s LCD-toting memory card.

One of the more unique aspects of the Sega Dreamcast is the visual memory unit, a 128-KB memory card with a 48 32 resolution LCD monochrome screen. The VMU has clever uses for memory card management (you can manipulate and delete saves without plugging it into a Dreamcast and even connect two memory cards to trade saves), but we’re really interested in it for its ability to store games. It comes with a battery and built-in controls (a D-pad minicontroller and two buttons), so you can play standalone games using it, even though it normally plugs into your Dreamcast controller.

Basically, the device resembles a teeny tiny Nintendo Game Boy. As such, it’s eminently hackable.

VMU History

The VMU, also known as the Visual Memory System (VMS) in the United States, never reached its full potential during the height of the Dreamcast’s popularity. If connected to your Dreamcast controller, it would sometimes show the game, logo, vital statistics, or other information while playing games. Some multiplayer games provided personal data, hidden from your opponents.

You can also use standalone VMU games with a few commercial titles. Games such as Power Stone use standalone VMU games intriguingly. Sega’s Sonic Adventure is particularly interesting because it allows you to grow a cute-looking Chao creature on your VMU and then import this data into the Dreamcast game. There were also several official VMU ...

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