IBM 86601RU Hardware Maintenance Manual - Page 179

Universal serial bus ports: The system board in the Netfinity 5500 contains two universal serial bus (USB) ports. Each USB port has an external connector on the rear on the server for attaching devices that previously used serial, parallel, keyboard, mouse, and game ports. USB is an emerging serial interface standard for telephony and multimedia devices. USB technology uses Plug and Play to determine what device is attached to the connector. Each USB device is accessed by a unique USB address. A device called a hub is used to convert the USB port into multiple attachment points. A hub has multiple ports where peripherals can be attached. USB provides 12 megabits-per-second (Mbps) bandwidth with a maximum of 63 peripherals and a maximum signal distance of five meters (16 ft.) per segment. Note If more than one USB device is to be attached, then the device must be connected to a hub. Table 7 shows the pin-number assignments for the USB connectors. Table 7. USB Connector Pin-Number Assignments Pin Signal 1 VCC 2 −Data 3 +Data 4 Ground Netfinity 5500 - Type 8660 171