Loading AI tools
Memory card format From Wikipedia, the free encyclopedia
The xD-Picture Card is an obsolete form of flash memory card, used in digital cameras made by Olympus, Fujifilm, and Kodak during the 2000s. The xD in the xD-Picture Card stands for eXtreme Digital.
 | This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these messages)
|
 | |
A 16 MB Fujifilm xD Card | |
| Media type | Memory card |
|---|---|
| Capacity | Maximum 512 MB (original) maximum 2 GB (Type M/M+, Type H) |
| Developed by | Olympus, Fujifilm |
| Dimensions | 20 mm × 25 mm × 1.78 mm |
| Weight | 2.8 g |
| Usage | Digital cameras, voice recorders |
| Released | July 2002 |
| Discontinued | 2009 |
xD cards were manufactured with capacities of 16 MB[lower-alpha 1] up to 2 GB.[lower-alpha 2][1] The standard was phased out in the late 2000s in favour of the SD card, which had been its primary competitor.[2]
The cards were developed by Olympus and Fujifilm, and introduced into the market in July 2002. Toshiba Corporation and Samsung Electronics manufactured the cards for Olympus and Fujifilm. xD cards were sold under other brands, including Kodak, SanDisk, PNY, and Lexar, but were not branded with the respective companies' logos, except for Kodak. Previously, xD competed primarily with Secure Digital (SD) cards, CompactFlash (CF), and Sony's Memory Stick. Because of its higher cost and limited usage in products other than digital cameras, xD lost ground to SD, which is broadly used by cellular phones, personal computers, digital audio players and many other digital cameras.
Olympus began to move away from the xD format with the mid-2009[3] announcement of the E-P1 camera, which supported only Secure Digital memory cards.[4] As of Spring 2010, all new Olympus cameras announced at the 2010 Consumer Electronics Show and Photo Marketing Association International Trade Show can use SD cards.[5][6][7][8][9][10] This changeover to the SD card format has never been officially announced by Olympus Corporation. The higher-end DSLR cameras such as the E-3 and E-5 among others continue to use CompactFlash cards as well. Certain final Olympus cameras using xD cards are also supporting microSD cards with a special adapter.
Fuji released its last digital camera accepting that card, namely Fujifilm FinePix F200EXR (a variant of 2008 FinePix F100fd), being released back in Q2 2009, as being moving away from xD format since Q4 2008.
Amazon Best Sellers in xD-Picture Cards reports no products offered with a Date First Available since 4 August 2009.[11][12]
The original xD cards (Type S) were available in 16 MB to 512 MB capacities. The Type M card, released in February 2005,[13] uses multi-level cell (MLC) architecture to achieve a theoretical storage capacity of up to 8 GB. As of June 2010[update], Type M cards are available in sizes from 256 MB to 2 GB. However, the Type M suffers from slower read/write speeds than the original cards.
The Type H card, first released in November 2005,[14] offers higher data rates than Type M cards (theoretically as much as 3 times faster). As of 2008, Type H cards were only available in 256 MB, 512 MB, 1000 MB, and 2000 MB capacities. Both Fuji and Olympus discontinued the production of Type H cards in 2008, citing high production costs.[15]
The Type M+ card, first released in April 2008,[16] offers data rates 1.5 times that of Type M cards. As of 2008, cards are available only in 1 and 2 GB capacities.
Olympus says that its xD cards support special "picture effects" when used in some Olympus cameras, though these software features are not intrinsically hardware-dependent. Type H and M+ cards however, are required in newer models to capture video at high rate (640×480 @ 30fps). Due to changes in the cards' storage architecture, newer Type M and H cards may have compatibility issues with some older cameras (especially video recording). Compatibility lists are available for Olympus: Olympus America's[17] and Fujifilm's.[18] Newer cards are incompatible with some card readers.
 |
Pictures may be transferred from a digital camera's xD card to a personal computer by plugging the camera into the PC by a USB or IEEE 1394 cable, or by removing the card from the camera and inserting it into a card reader. In both cases, the computer sees the card as a mass storage device containing image files, although software or firmware can alter this representation. Card readers may be integrated into the PC or attached by cable. Adapters are available to allow an xD picture card to be plugged into other readers (and in some cases cameras), including PC card, parallel port, CompactFlash and SmartMedia. A chart showing which sizes and types of xD cards were available can be found below.
| Type | Write speed (MiB/s) |
Read speed (MiB/s) |
Capacities available (MB) | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 16 | 32 | 64 | 128 | 256 | 512 | 1000 | 2000 | |||
| Standard | 1.3 | 5 | Yes | Yes | No | No | No | No | No | No |
| 3 | 5 | No | No | Yes | Yes | Yes | Yes | No | No | |
| M | 2.5 | 4 | No | No | No | No | Yes | Yes | Yes | Yes |
| H | 4 | 5 | No | No | No | No | Yes | Yes | Yes | Yes |
| M+ | 3.75 | 6 | No | No | No | No | No | No | Yes | Yes |
Detailed specifications are tightly controlled by Olympus and Fujifilm, which charge licensing fees and royalties and require non-disclosure agreements in exchange for the technical information required to produce xD-compatible devices.[19]
The memory format used is not well documented. It is difficult to study it directly, since most camera devices and most USB card readers do not provide direct access to the flash memory. Since the cards are controller-less, cameras and card readers must perform wear leveling and error detection. They normally hide the portion of the memory which stores this information (among other things) from higher level access.[20]
However, a few models of xD card readers based on the Alauda chip do allow direct access (bypassing the above mechanisms) to an xD card's flash memory. These readers have been reverse-engineered and Linux drivers have been produced by the Alauda Project,[21] which has documented the on-chip data structures of the xD card.[22] According to this information, xD card headers are similar to those used by SmartMedia, and include chip manufacturer information.
| This section possibly contains original research. (July 2011) |
At the raw hardware level, an xD card is simply an ordinary NAND flash integrated circuit in an unusual package. Comparing the pinout of an xD card[23][24] to the pinout of a NAND flash chip in a standard TSOP package,[23] one finds a nearly one-to-one correspondence between the active pins of the two devices. xD cards share this characteristic with the older SmartMedia cards, which are also basically raw NAND flash chips, albeit in a larger package.
xD and SmartMedia cards can be used by hobbyists as a convenient source of NAND flash memory chips for custom projects. For example, the Mattel Juice Box PMP can be booted into Linux using a modified cartridge containing an xD card with a boot image written on it. Additionally, SmartMedia and xD card readers can be used to read the data from NAND flash chips in electronic devices, by soldering leads between the chip and the card reader.[25][26]
Some Olympus cameras offer camera-based panoramic processing. In those cameras that support both xD and CompactFlash cards, panoramic processing only works with images stored on the xD card, if installed. Newer Olympus cameras have neither xD cards nor this restriction.
Unsubtantiated reports claim that some cameras such as the E-450 only support panoramic processing when using Olympus branded xD cards. The model numbers have not been documented. In this case, there appears to be a workaround: it appears that the card manufacturer information is simply stored in the flash memory, in the Card Information Structure.[21][22] Thus, it is possible to alter another brand of xD card to present itself as Olympus xD card by accessing the raw flash memory. This can be done by using a hacked device driver for a USB card reader.[27]
Seamless Wikipedia browsing. On steroids.
Every time you click a link to Wikipedia, Wiktionary or Wikiquote in your browser's search results, it will show the modern Wikiwand interface.
Wikiwand extension is a five stars, simple, with minimum permission required to keep your browsing private, safe and transparent.
