|Generation||Sixth generation era|
|Media||Dreamcast GD-ROM (used for content transfer)|
|CPU||8-bit Sanyo LC8670|
|Power||2 × CR2032 lithium batteries|
The VMU, or Visual Memory Unit, also referred to as the Visual Memory or VM in Japan (ビジュアルメモリ) 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), multi-player gaming capability (via connectors at the top), 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, 6 months before Sony released a similar device (albeit lacking any of the VMU's second-screen functionality) for its PlayStation console.
While its most basic function is as a removable storage device, the VMU may also serve as an auxiliary display during normal gameplay and, through the use of additional software (distributed as extras on Dreamcast GD-ROMs), acts as a handheld game console. Console-like features of the VMU include a screen, speaker, proper directional pad, four action buttons, the ability to connect and interact with other VMUs, and the ability to download additional games. While the standard VMU is white, colors were expanded to include many variations. Japan even saw the release of branded VMUs, such as those by Sonic Team, Capcom and Hello Kitty.
For use as a memory card and second-screen, the VMU is plugged directly into one of two slots on a Dreamcast controller (up to two VMUs may be plugged in each controller, and eight VMUs per Dreamcast console).
Upon initial use, the player is prompted to set the date and time, and then select from a group of bitmap images to serve as the default background for the VMU (various Dreamcast titles may offer players additional background images for the unit). This image is displayed while the Dreamcast console is in the operating system menu.
When operated independently of the Dreamcast console, the VMU acts as a file manager, clock/calendar (with selectable clock animations), and handheld game console. VMUs may also connect to each other directly to facilitate file transfer or multiplayer gaming.
The VMU runs on two CR-2032 lithium batteries which are inserted into the rear of the VMU under a screw-secured lid. Without battery power, the VMU still functions as a memory card and auxiliary display, but cannot play downloaded mini-games. Additionally, a VMU without battery power will beep when the Dreamcast is powered on (if the VMU is inserted into a connected Dreamcast controller).
- CPU: Sanyo LC8670 (8-bit CPU)
- Memory: 128KB flash memory.
- Display: 48 dot width × 32 dot height, LCD
- Sound: 1-channel PWM sound source
- Switches: Digital D-Pad, 4 input buttons, 1 reset button
- Functions: Memory card, second screen, mini-games/apps, calendar, file manager
- 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
- Weight: 45 g (1.6 oz)
The VMU has 128KB of flash memory, however by default 28KB is reserved for system use leaving 100KB for data storage, which is divided into 200 'blocks' - 1 block equaling 512 bytes. In recent years homebrew programs like Dream Explorer (aka VMU Tool) have allowed users to unlock an extra 44 blocks (22KB) of this reserved space increasing the overall VMU capacity to 244 blocks. However, a handful of games might be unable to detect the memory card if this is done, although none have been reported apart from DreamKey/DreamPassport and Metropolis Street Racer.
Minigames and in-game features
Several titles for the Dreamcast include mini-games that can be downloaded onto a VMU. The Sonic Adventure series, for instance, include the Chao Adventure mini-games (Chao Adventure and Chao Adventure 2 which features more activities and items). In the games, players can transfer Chao eggs to the VMU and partake in various activities to increase the stats of their hatched Chao, whereupon they can upload their improved Chao back into the Dreamcast game. Sega GT includes Pocket GT, a top-down racer in the style of the 8-bit SpyHunter games.
In other video games, statistics such as the current health condition are displayed on the VMU for convenience (as in Resident Evil: Code Veronica) or to enhance multi-player gaming (for example, NFL 2K2 allowed the VMU to display secret plays not viewable to other players).
There are also numerous homebrew games, original creations and ports of famous games, that are freely available on the net and can be installed and played on a VMU. These games include: Metroid, Pacman, Breakout, Space Invaders, Tetris, VMU Fighter (a side-scrolling shoot 'em up), Chao Editor (to create and edit your own Chao), VMU Football (an American football game), VMU-a-Sketch (a digital Etch-a-sketch pad), and 3D FPS (a first-person-shooter).
|Dreamcast game||VMU minigame||In-game features|
|Cardcaptor Sakura: Tomoyo no Video Daisakusen||?||?|
|Daytona USA||N/A||Shows a steering wheel in game while driving|
|Demolition Racer: No Exit||?||?|
|Dino Crisis||N/A||Health Condition and Ammo Count|
|Evil Twin: Cyprien's Chronicles||Four mini-games made available through downloads (they were not included in the full game due to time constraints)||?|
|Evolution: The World of Sacred Device||?||Health Condition|
|Evolution 2: Far Off Promise||12-hour clock||N/A|
|Godzilla Generations (Japanese Version)||?||?|
|Grand Theft Auto 2||?||Shows ammunition for gun player is holding|
|Jet Set Radio / Jet Grind Radio [USA]||Graffiti Transfer App||N/A|
|Marvel vs. Capcom 2: New Age of Heroes||Character, Character Color and Stage Transfer App that allows players to trade unlockables from the main game with other players||?|
|NBA 2K1||?||Player energy and foul stats|
|NFL 2K||?||Secret plays|
|NFL 2K1||?||Secret plays|
|NFL 2K2||?||Secret plays|
|NFL Blitz 2000||?||Secret plays|
|Power Stone||Three mini-games: Gunrock’s Gun-Gun Slot, Falcon’s Aerial Adventure, and Ayame’s Shuriken Training||?|
|Power Stone 2||App that allows players to view and trade items, cards, materials and essences collected in the main game with other players||?|
|Quake III Arena||Maze mini-game that allows you to collect various trophies earned in the main game||Animation|
|Ready 2 Rumble||?||#Punches, HIT%|
|Resident Evil 2||?||Health condition|
|Resident Evil 3: Nemesis||N/A||Health condition|
|Resident Evil Code: Veronica||?||Health condition|
|Sakura Wars 3||?||Messages from the game's Kinematron are viewed on the VMU. During combat, the VMU acts as a map of the area, showing where the enemy units are located.|
|Seaman||An app to organize and raise food for Seaman to eat in the main game||Indicates if Seaman can hear you or not when using the Sega Dreamcast Microphone to speak to him.|
|Sega GT||Pocket GT, an 8-bit version of Sega GT. There are three sets of tracks available for the game: Japan, Europe, and U.S., with each set featuring six tracks. There is also a training mode that allows you to raise your players stats in the main game||N/A|
|Sega Rally 2||Stats and records||N/A|
|Shenmue||?||Shows moves during fighting game training.|
|Silent Scope||?||Sniper rifle scope view|
|Skies of Arcadia||Pinta's Quest, a miniature RPG based on random encounters. Items and Gold gained within the minigame can be loaded into the main game's inventory||Signaled to player that a Cham was nearby|
|Sonic Adventure||Chao Adventure, a mini-game that allows you to transfer Chao from the main game into the VMU and train them independently, thus increasing their speed and strength. Many items can be collected and the main game's characters (such as Sonic, Tails, Knuckles, Amy and Big) can be met. The stronger, faster Chao may then be transferred back into the main game. By connecting two VMU units together, two Chao can also be breed.||N/A|
|Sonic Adventure 2||Chao Adventure 2, similar to the original Chao Adventure, but contains more activities, such as a Chao battle mode||Shows the Current Character being used.|
|Sonic Shuffle||N/A||Cards and items in hand|
|Soulcalibur (Japanese Version)||Three mini-games: Voldo Panic, a Circus Atari style game featuring Voldo; Word Scramble, a word puzzle game; and Cannon Dare, a full-fledged text adventure based in the Soulcalibur universe||Animated characters|
|Super Magnetic Neo||N/A||Alerted the player when a secret area was near by|
|Sword of the Berserk: Guts' Rage||?||?|
|Tech Romancer||Love & Punches, Phantasm Unit, and Rock Paper Scissors||?|
|Time Stalkers||Five mini-games: Dungeon IV (RPG where you fight monsters in randomly generated 3D dungeons), Editor (a picture editor/creator), Stuff (features four games, including a slots game), Moonlighter (pet simulator), and Great Game.||?|
|Tokyo Bus Guide||?||?|
|TrickStyle||TrickStyle Jr., a Snake style mini-game||?|
|Virtua Tennis||?||Shows simplified representation of match in wireframe perspective|
|Walt Disney World Quest: Magical Racing Tour||N/A||Shows the item caught|
|Who Wants To Be A Millionaire||N/A||Shows progress on the money ladder and lifelines in use|
|Zombie Revenge||Zombie Doubt (a memory test game), Zombie Fishing (fish for zombies), and Zombie Raising (a pet simulator type game)||?|
Multiple Dreamcast memory cards with no VMU features have been released. The cards therefore omit a display screen, input buttons, speaker and built-in clock. Some have the same 128 KB storage as the VMU, equivalent to 200 blocks, while others have multiple "pages" with each acting as a 128 KB memory card. In the latter case, a button or switch allows the gamer to select the desired memory card. This is due to the Dreamcast having a limit of 128 KB per individual memory card.
4x Memory Card
Sega released an official 4x Memory Card which offered four times the data storage of a standard VMU, with 800 blocks. It was released in Japan on December 14, 2000 as "Memory Card 4X", and in the USA as "4x Memory Card". A button is used to select one of four "pages", and a series of four orange LED on the card indicates which of these is currently in use. Not all games are compatible, so Sega released a list of incompatible games.
A limited edition Phantasy Star Online 4x Memory Card was also released in Japan to coincide with the games release. It was coloured blue and featured the Phantasy Star Online logo printed onto the casing.
The 4x Memory Card did not make it to retail in Europe despite a planned release (along with the Dreamcast Broadband Adapter which was also unreleased in Europe) due to the Dreamcast's unforeseeably short lifespan.
Third-party memory cards
The Nexus Memory Card is a third party version of the Visual Memory Unit that features four times the memory of a stock VMU with 800 blocks (4 megabit / 512 kilobytes) but lacks an LCD screen. The card is divided into 4 pages each with 200 blocks, each page can be selected using a button on the top left of the card. The Nexus Memory Card is slightly larger than the normal VMU and can be connected to a personal computer by USB, Parallel or Serial cable. A 3200 block (16 megabit / 2 megabytes) version of the Nexus is also available, but this model has been known to be unstable.
Nyko released two memory cards for the Dreamcast: the Jumbo Memory Pak X2 with twice the storage as a VMU, and the Hyperpak with four times the storage. The Hyperpak could also act as a Jump Pak by setting its switch to rumble mode.
The Performance Memory Card was a third-party basic memory card with the same 200 blocks of storage as a VMU. The Performance Mega Memory Card acted like a 4X Memory Card. It used a switch on its back to select the desired memory card "page". Unlike other memory cards however, the Performance model had to be removed from the controller before the "page" could be switched.
In a 10-year retrospective, GamesRadar called the VMU "one of our favorite storage devices." They offered praise for the originality of the device, as well its flexibility and commented that newer systems should have revisited the concept. However, they lamented that most games didn't find a useful purpose for it and that the device drained batteries quickly.
- PocketStation, a similar device by Sony for the PlayStation, released six months later.
- "Dreamcast Visual Memory Card VMS/VMU (Godzilla Design)". Play-Asia. Retrieved October 5, 2014.
- "Dream Explorer". Retrieved 2009-05-31.
- "VMU Wonders". The Dreamcast Junkyard. Retrieved October 6, 2014.
- "Dreamcast Memory Card 4X Details". Retrieved 2009-06-07.
- "DC Memory Card 4X Compatibility List". Retrieved 2009-06-07.
- "Review: 4X Nexus Memory Card w/PC Link". Retrieved 2009-05-31.
- Wide, Tyler (September 8, 2009). "A tribute to the Dreamcast VMU". GamesRadar. Retrieved October 11, 2012.