The PowerBook computer has two Universal Serial Bus (USB) ports that can be used to connect additional I/O devices such as a USB mouse, printers, scanners, and low-speed storage devices.
For more information about USB on the Macintosh computer, refer to Apple Computer's Mac OS USB DDK ATI Reference . Information is also available on the World Wide Web, at:
http://developer.apple.com/hardware/usb/
For full specifications of the Universal Serial Bus, refer to the USB Implementation Forum on the World Wide Web, at:
http://www.usb.org/developers/index.html