Universal Serial Bus (USB) allows up to 127 devices to be connected to a single computer and replaced parallel, serial, and SCSI ports. USB 1.1 had a transfer rate of 12Mbps while USB 2.0 increased it to 480Mbps. USB uses a hub system to provide power to connected devices and has cable length limitations of 5 meters without hubs.

1. Michael Sauers Technology Innovation Librarian Nebraska Library Commission

2. Universal Serial Bus “ Universal” in the sense that it replaces parallel, serial, and SCSI ports Allows up to 127 devices to be hooked up to a single computer Devices are designed to be “hot swapped”

4. USB 1.1 12Mbits/second USB 2.0 Finalized in 2001 480Mbits/second Backwards compatible with 1.1

5. Type A Type B Full-size Mini

6. 4.375V to 5.25V from the computer. If a hub is used then the devices downstream may only use a total of 4 units of power. Hubs with more than 4 ports require external power. If more power is needed than an external power supply must be connected. External hard drives

7. Available in various lengths 5m (16ft) length limitation

8. Overcomes the 5m limitation

14. Allows you to connect a hub via Ethernet so USB devices do not need to be connected directly to a computer. Good for networked storage and/or printers.

35. Up to 1GB USB 2.0 Backup software included

81. Yes, any of these devices that can store data are a potential security risk. Schneier on Security: Hacking Computers over USB Do you allow your patrons to use floppies or CDs? Do you allow your patrons to access their e-mail?

82. However, you can minimize most of these in a few simple steps: Deep Freeze or Centurion Guard Do not allow booting from the USB port Password protect your BIOS Separate the public computers from the library network

83. If the device requires a drive letter you may not have one available. Turn the key to the setting that disables the CD-ROM drive and reboot. The computer may not allow the device drivers to be installed. Reboot the computer into admin mode, insert the device, let the drivers install, remove the device, reboot into patron mode, reinsert the device.

84. USB devices are designed to be “hot swapped” but storage devices should not be removed while reading or writing data due to potential data loss. To properly remove a USB storage device, click on the or icon in your system tray then select the device. Wait for the “Safe to remove” message before unplugging the device.

85. USBGeek http://www.usbgeek.com HowStuffWorks.com http://computer.howstuffworks.com/usb.htm Wikipedia http://en.wikipedia.org/wiki/Usb Everything USB http://www.everythingusb.com/

86. Michael Sauers [email_address] http://travelinlibrarian.info/ http://del.icio.us/travelinlibrarian/usb