Hardware Reference
In-Depth Information
namefromtwospecialfeatures.Thefirstisencryptedstorageofdataforadditionalsecur-
ity, meeting current and future Secure Digital Music Initiative (SDMI) standards for port-
able devices. The second is a mechanical write-protection switch. The SD slot can also be
used for adding memory to Palm PDAs. The SDIO standard was created in January 2002
to enable SD slots to be used for small digital cameras and other types of expansion with
various brands of PDAs and other devices. The SD Card Association (
www.sdcard.org
)
was established in 2000 to promote the SD standard and aid the development of new
products. Note that some laptop computers have built-in SD slots.
Reduced-size versions of SD include MiniSD (introduced in 2003) and MicroSD (intro-
duced in 2005). MiniSD and MicroSD are popular choices for smart phones and can be
adapted to a standard SD slot. MicroSD is compatible with the TransFlash standard for
mobile phones.
The original SD standard allowed for memory card capacities of up to 2GB. To support
higher capacities the SDHC (High Capacity) standard was created in 2006. SDHC sup-
portscardsfrom4GBto32GBincapacity.Toincrease capacity beyond32GB,theSDXC
(eXtended Capacity) format was released in 2009. SDXC supports capacities of up to
2TB. Note that devices are backward compatible, meaning that a device that supports
SDXC also supports SDHC and standard SD cards. A device that supports SDHC also
accepts standard SD cards, but such a device does not support SDXC cards. Devices that
support only standard SD do not support either SDHC or SDXC cards.
Sony Memory Stick
Sony, which is heavily involved in both laptop computers and a variety of digital cameras
and camcorder products, has its own proprietary version of flash memory known as the
Sony Memory Stick. This device features an erase-protection switch, which prevents ac-
cidental erasure of your photographs. Sony has also licensed Memory Stick technology to
other companies, such as Lexar Media and SanDisk.
Lexar introduced the enhanced Memory Stick Pro in 2003. Memory Stick Pro includes
MagicGate encryption technology, which enables digital rights management, and Lexar's
proprietary high-speed memory controller. Memory Stick Pro is sometimes referred to as
MagicGate Memory Stick
.
The Memory Stick Pro Duo is a reduced-size, reduced-weight version of the standard
Memory Stick Pro. It can be adapted to devices designed for the Memory Stick Pro.
Sony later released “Mark 2” certified versions of the Memory Stick Pro in 2008. This
certification indicated that the cards were suitable for use with AVCHD (Advanced Video
Coding High Definition) recording devices. Sony also released a smaller Memory Stick
Micro (also called M2) format in 2006, which was designed to compete with microSD.
