Apple iMac - Manual (Page 28)

C H A P T E R 3
Devices and Ports
28 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”
■ “Keyboard”
■ “Mouse”
■ “Hard Disk Drive”
■ “Video Display”
■ “Infrared Communication Link”
■ “Sound System”
■ “Ethernet Port”
■ “Internal Modem”
USB Ports 3
The iMac computer has two Universal Serial Bus (USB) ports that are used to
connect the keyboard and mouse as well as additional I/O devices such as
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.