Sega Dreamcast VMU
The VMU, short for Visual Memory Unit (known as VMS, or Visual Memory System, in Japan, Europe, and Australia), is a memory card peripheral for the Sega Dreamcast. While its primary function is to serve as removable storage, the VMU can also act as an auxiliary display during gameplay and, with additional software, function as a handheld device. It features a small black-and-white screen, a speaker, a d-pad, and four buttons, giving it console-like capabilities. Initially released in white, the VMU later became available in transparent blue, green, black, and red.
Mini-games[]
Sega Dreamcast VMU with third-party 800 block/4x memory card (left).
Several Dreamcast titles included mini-games that could be downloaded onto a VMU. For example, the Sonic Adventure series featured the Chao Adventure mini-game. Players could transfer Chao eggs to the VMU, play to increase the stats of their hatched Chao, and then upload their improved Chao back into the Dreamcast game.
Dreamcast titles that include VMU games and extra features:[]
- Evolution 2 (12 Hour Clock)
- Godzilla Generations (Japanese Version)
- Power Stone
- Power Stone 2
- Marvel Vs. Capcom 2
- Namco Museum
- NFL 2K
- NFL 2K1
- NFL 2K2
- Quake III Arena
- Resident Evil 2
- Sakura Wars
- Sakura Wars 2: Thou Shalt Not Die
- Sakura Wars 3: Is Paris Burning?
- Sakura Wars 4: Fall in Love, Maidens
- Sega GT
- Shenmue
- Skies of Arcadia
- Sonic Adventure
- Sonic Adventure 2
- Soulcalibur (Japanese Version)
- Tech Romancer
- Time Stalkers
- TrickStyle
- Zombie Revenge
- Tokyo Bus Guide
Hardware[]
The VMU plugs directly into one of two slots on a Dreamcast controller, with each controller supporting up to two VMUs. When used independently of the Dreamcast console, the VMU functions as a file manager with basic game console features. VMUs can also connect directly to each other for file transfers or multiplayer gaming.
When using the VMU for the first time, players are prompted to choose from a selection of simple bitmap images to set as the default background. This image is displayed while the Dreamcast is in the system menu but is typically replaced by a simplified logo during gameplay. Some games display custom animations on the VMU screen, and certain titles even offer new background images for the device.
The VMU is powered by two CR-2032 lithium batteries, which are inserted under a screw-secured lid on the back. Without batteries, the VMU can still function as a memory card and auxiliary display but cannot play downloaded mini-games.
Technical specifications[]
- CPU: 8-bit (Sanyo LC8670 "Potato")
- Memory: 128 KiB (200 blocks of 512 bytes each)
- Display: 48 dot width × 32 dot height, LCD
- Display size (width×height): 37 mm × 26 mm (1.46 in × 1.02 in)
- Case dimensions (width×height×depth): 47 mm × 80 mm × 16 mm (1.85 in × 3.15 in × 0.63 in)
- Power source: 2 × CR2032 batteries with auto-off function, Lasts From 20-30 Minutes
- Sound: 1-channel PWM sound source
- Weight: 45 g (1.6 oz)
Extra blocks[]
The VMU comes with extra 41 blocks of available storage, but with programs like Dream Explorer (also known as VMU Tool), users can unlock this additional space, increasing the total capacity to 241 blocks.
However, it's been noted that a few games may have trouble detecting the memory card after doing this, although the only reported cases involve DreamKey/DreamPassport and Metropolis Street Racer.
Dream Explorer official site
Dream Explorer 0.8.5 hosted image
Third Party Cards[]
Nexus Memory Card[]
The Nexus Memory Card is a third party version of the Visual Memory Unit that features four times the memory (4 mebibits / 800 blocks). The Nexus Memory Card is physically larger than the normal VMU and can be connected to a personal computer by USB, Parallel or Serial cable. A 16 mebibit (3200 block) version of the Nexus is also available, but this model has been known to be unstable.
Nyko Hyperpak[]
The Nyko Hyperpak was a basic memory card without the screen and VMU buttons. However, it was four times the size of a normal memory unit and also had a switch that would switch the device from memory mode to rumble mode. It was larger than a standard VMU but had no way to connect to a personal computer.