U3

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This article is about the computer company and design specification. For other uses, see U3 (disambiguation).
U3 LLC.
Type Private
Founded 2004
Headquarters Redwood City, CA
Industry Computer
Website www.u3.com

U3 is a company producing a proprietary method of auto-launching applications from specially formatted USB flash drives. Flash drives adhering to the U3 specification are termed "U3 smart drives". U3 smart drives come preinstalled with the U3 Launchpad, which looks similar to the Windows OS start menu and controls program installation. The method works with recent Microsoft Windows systems only. Applications which comply with U3 specifications are allowed to write files or registry information to the host computer, but they must remove this information when the flash drive is ejected. Customizations and settings are instead stored with the application on the flash drive.

Microsoft and SanDisk are working on a successor called StartKey.

Contents

[edit] U3 platform

[edit] Hardware

A U3 flash drive presents itself to the host system as a USB hub with a CD drive and standard USB mass storage device attached.[1]

  • This configuration causes Windows disk management to show two drives:
    1. A read-only ISO 9660 volume on an emulated CD-ROM drive with an autorun configuration to execute the U3 LaunchPad, and
    2. A standard flash drive (FAT formatted) that includes a hidden "SYSTEM" folder with installed applications.
  • U3 compliant applications can be (optionally) preloaded by manufacturers.

[edit] U3 Launchpad

U3 Launch Pad example.

The U3 Launchpad is a Windows program manager that is preinstalled on every U3 smart drive.[2]

The U3 Launchpad automatically starts at insertion of a U3 enabled device.

[edit] U3 applications

To be fully U3 compliant, an application has to be programmed to clean up its own data from the local machine. It must also be packaged in U3's special program format. U3 applications will only run from a U3 device. The U3 programs are all downloaded from the U3 website, such apps include Opera and Skype, accessible from the U3 menu, and not needed to be installed on the PC/Laptop.

[edit] APIs

The U3 APIs allows U3 Programs lower-level access to USB flash drive, and to query the drive letter. The U3 APIs primarily allow developers who choose to use more of the power of U3 to control how their application handles things like device removal and saves data back to the drive such as configuration or documents. The flash drive will then act like another hard drive in your machine.

[edit] Compatibility

The latest version of U3 launchpad supports Windows 2000 with Service Pack 4, Windows XP, Windows Vista and Windows 7.

Data will continue to be accessible from any OS capable of reading from USB Mass Storage Devices, unless the U3 device is password-protected.[note 1]

[edit] Issues

Compatibility issues have been noted as late as July 2007 under Windows XP Pro between certain Windows drivers that are associated with high-volume data transfers to CD writers and with certain drivers employed by digital video cameras, resulting in a crash of the XP operating system. According to SanDisk's community forums [3], as of February 2008 many users were still exhibiting Vista compatibility issues with U3 equipped flash drives regardless of the U3 Launchpad version.

Apparently, this is related to specific hardware/firmware versions of the flash drive itself [4], as removing the U3 software will still not allow Vista to recognize the USB key. While SanDisk has claimed that a patch for the U3 is in the works, Microsoft has released an update to Vista (KB940199) [5], allowing some users to successfully use the flash drive as intended.

One of the affected USB Flash drives is the SanDisk Cruzer Titanium series with device numbers 2.17, 2.18, 2.19 and 2.20.

By March 2008, SanDisk has released a new Launchpad update for these device versions of Cruzer Titanium that will make these devices fully compatible with Windows Vista [6]. This will allow Vista users to both use the drive for data storage and the U3 functionality as they are used to under Windows XP, including the password protection.

U3 technology is not compatible with many consumer devices such as digital camcorders, digital cameras, musical keyboards and workstations. Manufacturers of musical keyboards such as Korg, Roland, and Yamaha provide USB and SD card slots into which drives containing system software and musical sound samples can be plugged. However any hidden partition on the drive such as a U3 partition causes the equipment to malfunction.

[edit] Developer resources

Information on building U3 compliant applications and the U3 software development kit, are available to registered developers at the official U3 website. Individuals must register (as a company) to download the SDK, or participate in the forums. [7] Applications that do not require installation steps in order to run can easily utilize U3 with little or no modification by taking steps to either not modify the host systems files or registry, or undoing all changes when the application terminates. A wizard which packages your distribution files and creates the special "manifest" file is provided.

Reformatting the drive will remove some of the software, but not all of it. The virtual CD-ROM drive cannot be removed by reformatting because it is presented to the host system as a physical device attached to a USB hub[8]; the official U3 Launchpad Removal Software, available on the manufacturer's website, disables the virtual CD drive device, leaving only the USB mass storage device active on the U3 USB hub controller, at which point the remaining software is removed by a subsequent format, performed by the removal software itself.

[edit] Benefits

Portability
This software automatically attempts installation of U3 components (U3 Launchpad) on the harddisk drive and associated System Registry entries on the Host Computer. Afterwards the U3 software can be taken with all its personalized settings to any computer running a compatible version of Microsoft Windows (though no other operating system), with no need to install the software if not already there, or to use different settings and options, the initialization Host computer requires Administrative privileges and no need for administrator access privileges on subsequent computers.[citation needed]
Ease of use
Programs are run from the Launchpad, functionally similar to the Windows Start menu familiar to most users of Windows XP.
No need of admin rights on other computers
New software can be installed to a U3 flash drive without the requirement for administrative privileges on the host computer.
Virus protection
Many U3 drives come with virus protection software which gives protection against being infected by or spreading computer viruses.
Data security
Most U3 drives on the market feature a security lock within the U3 Launchpad. This loads the CD partition first and can be user-configured to require a password to be entered; otherwise the data partition will not load. The drive is supposed to seal itself after a certain number of invalid password entries, requiring a reformat.[9]

[edit] Criticisms

 This section may contain original research or unverified claims. Please improve the article by adding references. See the talk page for details. (September 2008)

Numerous criticisms have been made of the U3 platform. These criticisms are:

Freezing the computer
There is a strong possibility of locking up or freezing a computer with certain CD/DVD burning software installed. for example Nero v7 and Roxio DirectCD[10].
Proprietary format / closed platform
The U3 platform is a "closed" platform / proprietary format, and unavailable for developers[11]. SanDisk, the rights holders for U3, ask for a 5% royalty from USB flash drive manufacturers who wish to implement the platform on their products.
Non-Windows issues
The U3 software and applications only work on Windows. The effect of the U3 flash drive on non-Windows operating systems is variable - it will appear as a read-only CD-ROM drive containing some Windows software on Mac OS and Linux. The use of non-standard CD-ROM emulation may cause errors - under Linux you will see kernel errors like "end_request: I/O error, dev sr1, sector 196600" relating to the emulated drive. The U3 Windows software takes up space on the flash disk and can't be deleted without using the Windows/Mac uninstaller mentioned above.
Two drive letters
As a work-around to the lack of Auto-Play for Flash drives on older versions of Windows, the U3 software creates two drive letters (one which presents itself as a CD to allow Windows' auto-play to start the launcher, and another for storing user data). Although this is the only way to implement auto-start functionality on pre-Windows XP systems, it could be considered a kludge, and the extra drive letter created can be an annoyance. However, it is trivial to prevent Windows from allocating a drive letter for the "CD drive" via the Windows "Disk Management" tool.
Incompatibility with certain platforms
Some host systems – such as photo kiosks, consumer electronics, and other embedded computing devices – cannot correctly mount U3 "smart drives." The problem may arise because the emulated CD-ROM is the first drive presented to the host system. As such, the device is detected as a CD-ROM drive or not at all. Although some newer photo kiosks are U3 aware[12] and can overcome this limitation, it still exists on many platforms. In embedded systems, where program memory is limited, it may be very costly in terms of system resources to make a device U3 aware. In such cases it is far more logical to leave this functionality out.

[edit] See also

[edit] Notes

  1. ^ [1] "If the OS in question can normally see ordinary USB flash drives, then the U3 smart drive removable mass storage area (domain) should still be available for standard file system activities unless it is a private area protected by a password or with Novell ZENworks."

[edit] References

  1. ^ http://technet.microsoft.com/en-us/magazine/cc137730.aspx Microsoft Technet Magazine, January 2008
  2. ^ U3 Knowledge Base: Can I access the Documents directory on my U3 smart drive without running the U3 Launchpad?
  3. ^ [2]
  4. ^ [3]
  5. ^ [4]
  6. ^ [5]
  7. ^ U3 Forum registration guidelines
  8. ^ http://technet.microsoft.com/en-us/magazine/cc137730.aspx Microsoft Technet Magazine, January 2008
  9. ^ U3 Newbie Guide
  10. ^ The U3 Launchpad doesn't run. What should I do?
  11. ^ http://www.u3.com/developers/default.aspx "At this point we do not accept any new releases. Thank you U3.com"
  12. ^ U3 Drives Finally Get Along with Photo Kiosks

[edit] External links

Retrieved from "http://en.wikipedia.org/wiki/U3"
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