View source for VMU

{{short description|Memory card for the Dreamcast}}
{{Other uses|VMU (disambiguation)}}
{{Use mdy dates|date=December 2015}}
{{Infobox information appliance
| title = Visual Memory Unit
| image = Sega-Dreamcast-VMU.jpg
| image_size = 200px
| manufacturer = [[Sega]]
| type = [[Peripheral]], [[handheld game system]]
| generation = [[Sixth generation of video game consoles|Sixth]]
| release date  = {{vgrelease|JP|July 30, 1998}}{{vgrelease|NA|September 9, 1999}}{{vgrelease|EU|October 14, 1999}}{{vgrelease|AUS|November 30, 1999}}
| lifespan = 1998–2001
| discontinued = {{vgrelease|JP|March 30, 2001}}
| storage = 100 KB (200 blocks) accessible<br/>28 KB (56 blocks) system data
| CPU = 8-bit Sanyo LC8670
| Power = 2 × CR2032 [[Lithium metal battery|lithium batteries]]
| input = * 4 x digital buttons
* Digital [[D-Pad]]
| media = [[Dreamcast]] [[GD-ROM]] (used for content transfer)
| weight = 45g
}}

The '''Visual Memory Unit''' ('''VMU'''), also referred to as the {{nihongo|'''Visual Memory System'''|ビジュアルメモリ|Bijuaru Memori}} ('''VMS''') in [[Japan]], 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 (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 (franchise)|Godzilla]] edition VMU, preloaded with a [[virtual pet]] game, was released on July 30, 1998, in Japan.<ref>{{cite web|title=Dreamcast Visual Memory Card VMS/VMU (Godzilla Design)|url=http://www.play-asia.com/dreamcast-visual-memory-card-vmsvmu-godzilla-design-paOS-13-49-en-70-5wz.html|website=Play-Asia|access-date=October 5, 2014}}</ref>

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-ROM]]s), acts as a [[handheld game console]]. Console-like features of the VMU include a screen, speaker, proper [[directional pad]], four action [[Button (control)|buttons]], the ability to connect and interact with other VMUs, and the ability to download additional games.

==Hardware==
[[File:Sega-Dreamcast-Cont-n-VMU.jpg|thumb|right|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.]]
[[File:Sega-Dreamcast-Controller-wVMU-FL.jpg|thumb|right|The VMU shown inside the controller]]
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 [[CR2032 battery|CR-2032]] [[lithium battery|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)

The VMU has 128 [[kilobyte|KB]] of flash memory, but by default 28 KB is reserved for system use leaving 100 KB for data storage, which is divided into 200 'blocks' – one block equaling 512 bytes. In recent years, homebrew programs like Dream Explorer (aka VMU Tool) have allowed users to unlock an extra 44 blocks (22 KB) of this reserved space<ref>{{cite web | title=Dream Explorer | url=http://bswirl.kitsunet.org/vmutool/release/about/?lg=en&menu= | access-date=May 31, 2009 | archive-date=October 7, 2011 | archive-url=https://web.archive.org/web/20111007145443/http://bswirl.kitsunet.org/vmutool/release/about/?lg=en&menu= | url-status=dead }}</ref> 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]].{{Citation needed|date=August 2023}}

==Minigames and in-game features==
{{unreferenced section|date=December 2022}}
[[File:Dreamcast-VMUs-Hooked.jpg|thumb|VMUs can be coupled to trade files or for multi-player gaming.]]
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 (Sonic the Hedgehog)|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 [[internet]] and can be installed and played on a VMU. These games include: ''[[Metroid]]'', ''[http://www.deco.franken.de/myfiles/pacman.html VMU Mini Pacman]'', ''[[Breakout (video game)|Breakout]]'', ''[[Space Invaders]]'', ''[[Tetris]]'', ''VMU Fighter'' (a side-scrolling shoot 'em up), ''VMU Football'' (an American football game), ''VMU-a-Sketch'' (a digital Etch-a-sketch pad), and ''3D FPS'' (a first-person-shooter).<ref>{{cite web|title=VMU Wonders|url=http://www.thedreamcastjunkyard.co.uk/2006/05/vmu-wonders.html|publisher=The Dreamcast Junkyard|access-date=October 6, 2014}}</ref>

{| class="wikitable"
|-
! Dreamcast game
! VMU minigame <!-- used when disconnected from the Dreamcast --->
! In-game features <!-- such as calling plays in a football game --->
|-
| ''[[Cardcaptor Sakura|Cardcaptor Sakura: Tomoyo no Video Daisakusen]]''
| Three mini-games:
* Breakout
* Oyatu
* Tobakero
Clock (four themes)
| {{dunno}}
|-
| ''[[Carrier (video game)|Carrier]]''
| {{n/a}}
| Health condition
|-
| ''[[D2 (video game)|D2]]''
| Photo viewer
| Compass
|-
| ''[[Dino Crisis (video game)|Dino Crisis]]''
| {{n/a}}
|
* Health condition
* Ammo count
|-
| ''[[Evil Twin: Cyprien's Chronicles]]''
| Four mini-games (downloadable)
| {{dunno}}
|-
| ''[[Evolution: The World of Sacred Device]]''
| {{dunno}}
| Health condition
|-
| ''[[Evolution 2: Far Off Promise]]''
| 12-hour clock
| {{n/a}}
|-
| ''[[F355 Challenge]]''
| {{n/a}}
| Arcade connectivity
|-
| ''[[Godzilla Generations]]'' (Japanese version)
| Three mini-games:
* Atsumete Godzilla
* Gamera Dream Battle
* Mothra Dream Battle
| {{dunno}}
|-
| [[Jet Set Radio|''Jet Set Radio'' / ''Jet Grind Radio'']]
| Graffiti transfer
| {{n/a}}
|-
| ''[[Marvel vs. Capcom 2: New Age of Heroes]]''
| Transfer characters, colors and stages
| Arcade connectivity
|-
| ''[[Namco Museum]]''
| ''Pac-It''
| {{n/a}}
|-
| ''[[NBA 2K]]'' / ''[[NBA 2K1|2K1]]'' / ''[[NBA 2K2|2K2]]''
| {{n/a}}
| Team statistics
|-
| ''[[NFL 2K]]'' / ''[[NFL 2K1|2K1]]'' / ''[[NFL 2K2|2K2]]'' / ''[[NFL Blitz|Blitz]]''
| {{dunno}}
| Secret plays
|-
| ''[[Pen Pen TriIcelon]]''
| {{n/a}}
| Currently selected playable character
|-
| ''[[Pop'n Music]]'' series
| ''Pop'n Music Anywhere'' mini-game
| Virtual ''Pop'n Music'' controller
|-
| ''[[Power Stone (video game)|Power Stone]]''
| Three mini-games:
* ''Gunrock’s Gun-Gun Slot''
* ''Falcon’s Aerial Adventure''
* ''Ayame’s Shuriken Training''
| {{dunno}}
|-
| ''[[Power Stone 2]]''
| View and trade items
| {{dunno}}
|-
| ''[[Quake III Arena]]''
| Maze mini-game
| Animation
|-
| ''[[Ready 2 Rumble]]''
| {{dunno}}
|
* Punch count
* Hit percentage
|-
| ''[[Resident Evil]]'' series
| {{dunno}}
| Health condition
|-
| ''[[Sakura Wars]]'' 3
| {{dunno}}
|
* Kinematron messages
* Area map
|-
| ''[[Seaman (video game)|Seaman]]''
| Organize and raise food for Seaman
| Seaman [[Dreamcast accessories#Microphone|microphone]] status
|-
| ''[[Sega GT]]''
| ''Pocket GT'' (Japan, Europe and US)
| {{n/a}}
|-
| ''[[Sega Rally 2]]''
| Stats and records
| {{n/a}}
|-
| ''[[Shenmue (video game)|Shenmue]]''
| ''Shenmue Goodies''
| Training instructions
|-
| ''[[Silent Scope (video game)|Silent Scope]]''
| {{dunno}}
| Sniper rifle scope view
|-
| ''[[Skies of Arcadia]]''
| ''Pinta's Quest''
| Cham alert
|-
| ''[[Sonic Adventure]]''
| ''Chao Adventure''
| Chao animation
|-
| ''[[Sonic Adventure 2]]''
| ''Chao Adventure 2''
| {{n/a}}
|-
| ''[[Sonic Shuffle]]''
| {{n/a}}
| Revealed card numbers
|-
| ''[[Soulcalibur (video game)|Soulcalibur]]'' (Japanese version)
| Three mini-games
| Animated characters
|-
| ''[[Super Magnetic Neo]]''
| {{n/a}}
| Secret area alerts
|-
| ''[[Tech Romancer]]''
| Three mini-games
| {{dunno}}
|-
| ''[[Time Stalkers]]''
| Five mini-games
| {{n/a}}
|-
| ''Tokyo Bus Guide''
| ''Traffic Signs Quiz''
| {{dunno}}
|-
| ''[[TrickStyle]]''
| ''[[Snake (video game genre)|TrickStyle Jr.]]''
| {{dunno}}
|-
| ''[[Virtua Tennis (video game)|Virtua Tennis]]''
| {{dunno}}
| Wireframe match
|-
| ''[[Zombie Revenge]]''
| Three mini-games
| {{dunno}}
|}

==Variants==
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 user 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===
[[File:Dreamcast MemoryCard4X.jpg|thumb|right|200px|The official Dreamcast 4x memory card has several lights on its front indicating the currently used storage "page".]]
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,<ref name="Dreamcast Memory Card 4X Details">{{cite web | title=Dreamcast Memory Card 4X Details | url=http://www.gamespot.com/news/2642229.html | access-date=June 7, 2009}}</ref> as "Memory Card 4X", and in the US 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.<ref>{{cite web | title=DC Memory Card 4X Compatibility List | url=http://www.gamespot.com/news/2646823.html | access-date=June 7, 2009}}</ref>

A limited edition ''[[Phantasy Star Online]]'' 4x Memory Card was also released in Japan to coincide with the game's release. It was coloured blue and featured the ''Phantasy Star Online'' logo printed onto the casing.<ref name="Dreamcast Memory Card 4X Details"/>

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 – although unofficial third party 4x Memory Cards were released in Europe.

===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.<ref>{{cite web | title=Review: 4X Nexus Memory Card w/PC Link | url=http://www.segatech.com/technical/nexus/index.html | access-date=May 31, 2009}}</ref> The Nexus Memory Card is slightly larger than the normal VMU and can be connected to a [[personal computer]] by [[USB]], [[D-subminiature|Parallel]] or [[D-subminiature|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.{{Citation needed|date=April 2008}}

[[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 September 2023, following a successful [[Crowdfunding in video games|crowdfunding]] campaign, Dreamware Enterprises released an aftermarket VMU update called the VM2. The VM2 features a backlit screen, a rechargeable battery with [[USB-C]] support, and [[MicroSD]] storage.<ref>{{cite web | url=https://www.theverge.com/2022/9/21/23365268/sega-dreamcast-vmu-virtual-memory-unit-card-2022-fundraiser-indiegogo-console | title=Sega Dreamcast's iconic memory card is making a (Fundraised) comeback | date=September 21, 2022 }}</ref>

==Reception==
{{Expand section|date=August 2023}}
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.<ref name=GR>{{cite web|url=http://www.gamesradar.com/a-tribute-to-the-dreamcast-vmu/|last=Wide|first=Tyler|title=A tribute to the Dreamcast VMU|publisher=GamesRadar|date=September 8, 2009|access-date=October 11, 2012}}</ref> In 2024, ''[[Time Extension]]'' called the VMU "an important evolution of the memory card concept".<ref>{{cite web |last1=McFerran |first1=Damien |title=In Memory Of Memory Cards |url=https://www.timeextension.com/features/in-memory-of-memory-cards |website=[[Time Extension]] |publisher=[[Hookshot Media]] |access-date=30 January 2024 |date=25 January 2024}}</ref>

==See also==
* [[PocketStation]], a similar device by Sony for the PlayStation, released six months later.

==References==
{{reflist}}

==External links==
* [https://web.archive.org/web/20110714050713/http://rvmu.maushammer.com/faq.html The (Unofficial) VMU FAQ (Wayback Machine)]

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{{Dreamcast}}
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{{DEFAULTSORT:Vmu}}
[[Category:Sega hardware]]
[[Category:Dreamcast]]
[[Category:Discontinued handheld game consoles]]
[[Category:Handheld game consoles]]
[[Category:Monochrome video game consoles]]
[[Category:Video game storage media]]
[[Category:Sixth-generation video game consoles]]

[[sv:Sega Dreamcast#VMU]]