The
xD-Picture Card is a type of flash memory memory card. xD stands for extreme digital.
It was developed by Olympus and Fujifilm, who introduced it to the market in July 2002. Toshiba Corporation and Samsung Electronics manufacture the cards for Olympus and Fujifilm. Other brands, including Kodak, SanDisk, and Lexar, now sell xD cards.
xD cards are used in Olympus, Kodak and Fujifilm digital cameras. Currently they are available in these capacities: 16MB, 32MB, 64MB, 128MB, 256MB, 512MB and 1GB (Type M). An xD card is 20mm × 25mm × 1.78mm and weighs 2.8 grams. The 16MB and 32MB models write at 1.3mb/s and read at 5mb/s. The 64MB, 128MB, 256MB and 512MB models write at 3mb/s and read at 5mb/s. The 1GB (Type M) model writes at 2.5mb/s and reads at 4.0mb/s.
The Type M was released in 2005. It uses Multi Level Cell (MLC) architecture to achieve higher storage capacity than the 512MB. Although Type M capacity will eventually stretch to 8GB, the 1GB card is currently the only card in this range. The Type M suffers some compatibility issues with older cameras (especially video recording) and marginally slower readwrite speeds than the 512MB card.
Pictures are transferred from the xD card to computer by plugging the camera into the PC (normally with USB) or removing the card and putting it into a card reader. In both these cases, the computer sees the card as a mass storage device with photos on it, although software or firmware can alter this. 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 PCMCIA, parallel port, CompactFlash and Smart Media.
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