USB mass storage device class

However, third-party applications add MSC emulation to most WM devices (commercial Softick CardExport and free WM5torage).

The AutoRun feature of Windows worked on all removable media, allowing USB storage devices to become a portal for computer viruses.

Third-party generic drivers, such as Duse, USBASPI and DOSUSB, are available to support USB mass-storage devices.

AIX has supported USB mass-storage devices since its 5.3 T9 and 6.1 T3 versions; however, it is not well-supported and lacks features such as partitioning and general blocking.

[6] The Xbox 360 and PlayStation 3 support most mass-storage devices for the data transfer of media such as pictures and music.

The USB mass-storage specification provides an interface to a number of industry-standard command sets, allowing a device to disclose its subclass.

Subclass codes specify the following command sets: The specification does not require a particular file system on conforming devices.

Based on the specified command set and any subset, it provides a means to read and write sectors of data (similar to the low-level interface used to access a hard drive).

This partition is often aligned to a high power of two of the sectors (such as 1 or 2 MB), common in solid state drives for performance and durability.

This simplifies distribution and access to drivers and documentation, primarily for the Microsoft Windows and Mac OS X operating systems.

Such drivers are required to make full use of the device, usually because it does not fit a standard USB class or has additional functionality.

The embedded USB mass storage is usually made permanently read-only by the vendor, preventing accidental corruption and use for other purposes (although it may be updated with proprietary protocols when performing a firmware upgrade).

Advantages of this method of distribution are lower cost, simplified installation and ensuring driver portability.