Hardware Reference
In-Depth Information
FIGURE 2.13
A Secure Digital memory card
Photo credit: Wirepath, Wikimedia Commons
For a very complete comparison of the various types and subtypes of
flash memory cards, including their exact sizes and features, see
http://
en.wikipedia.org/wiki/Comparison_of_memory_cards
.
Cards vary not only in their sizes, shapes, and capacities, but also in whether they
implement these features:
Write-Protection
Some types have a write-protection switch that enables you to set them
to read-only.
Digital Rights Management (DRM)
Some types support a form of security encryption
that allows you to make fi les on the card private.
Mobile Media Devices
A variety of mobile devices employ fl ash RAM as their primary means of storage. Today's
mobile devices include smart phones, hand-held gaming devices, music players, and more.
They all run their own proprietary OSs and applications, but they all rely on the same basic
nonvolatile RAM technology as a fl ash RAM device or solid-state drive to hold it.
Many devices are multifunction. For example, a typical smart phone serves not only
as a mobile phone, but also as a scheduling organizer, a music player, and even a Global
Positioning System (GPS) device.
Solid-State Hard Drives
A
solid-state hard drive
isn't really a drive, but it's called that for consistency with
mechanical hard drive terminology. Its central storage component is fl ash RAM, the same
as other fl ash RAM devices. It differs from other fl ash RAM devices primarily in the data
