Technical information

CHAPTER 3
Devices and Ports
30 USB Ports
This chapter describes both the built-in I/O devices and the ports for
connecting external I/O devices. Each of the following sections describes an
I/O port or device.
USB Ports 3
The PowerBook G3 Series 1999 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/dev/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
USB Connectors 3
The USB ports use USB Type A connectors, which have four pins each. Two of
the pins are used for power and two for data. Figure 3-1 is an illustration of a
Type A port and matching connector. Table 3-1 shows the pin assignments.