The Visual Memory Unit (VMU), also referred to as the Visual Memory System (VMS) in Japan and Europe, is the primary memory card produced by Sega for the Dreamcast home video game console. The device features a monochrome liquid crystal display (LCD), multiplayer gaming capability, second screen functionality, a real-time clock, file manager, built-in flash memory, and sound capability. Prior to the launch of the Dreamcast, a special Godzilla edition VMU, preloaded with a virtual pet game, was released on July 30, 1998, in Japan.
VMU
VMUs attach through either of two slots on the controller; the screen of the VMU attached in the front slot is visible through a window on the controller.
The VMU shown inside the controller
VMUs can be coupled to trade files or for multi-player gaming.
A memory card is an electronic data storage device used for storing digital information, typically using flash memory. These are commonly used in digital portable electronic devices, such as Digital cameras as well as in many early games consoles such as the Nintendo Wii. They allow adding memory to such devices using a card in a socket instead of protruding USB flash drives.
Miniaturization is evident in memory card creation; over time, the physical card sizes have become smaller.
Memory card in a digital SLR camera
Secure Digital card (SD)
MiniSD Card with an SD card adapter