In
recent years, most computers connect to external devices in
a new way, known as Universal Serial Bus (USB). USB is an
easy way to connect to numerous types of devices including
printers, digital cameras, game pads, joysticks, keyboards,
mouse devices, and storage devices etc. As USB is a very commonly
used standard, let us look at it in more detail and see how
it is supported in the University.
USB
versions
The latest
version of USB is called the USB version 2.0; its speed is
up to 480 Mbps. However, some old computers and old USB devices
belong to version 1.0 and 1.1, and they support only 12 Mbps.
However, all these versions are inter-compatible.
Support
of USB in CityU
All the
computers in CityU should support USB 1.1 or above. For Dell
desktop PCs of more than 2 years (e.g. model like GX200, GX400
and Precision220), they support version 1.1 only and most
of their USB ports are at the back of the PCs. For the latest
models (e.g. GX260, GX270 and Precision360), the USB ports,
which support version 2.0, are installed at the front of the
PCs and are normally covered by a movable door near the bottom
of the PCs. For public PCs like those in lecture theatres,
classrooms and express terminals, USB hubs are installed.
Please find out more by visiting them or calling us if you
need help.
Connecting
USB devices to your computer
You can
connect a USB device to your computer while the computer is
turned on.
However, DO NOT plug or unplug a USB device, especially a
storage device, while the device is in use, or you may damage
your files.
If necessary,
connect the USB device to a power source, as some devices
need extra power to drive. Standard USB port only provides
500mA which is not sufficient for most devices. If your USB
device does not have an attached USB cable, then plug one
into a corresponding USB port on the device and plug the other
end of the cable into an USB port on your computer. A standard
symbol for USB port looks like this:
If your computer doesn't have a free USB port, you may need
to add a USB hub and connect other USB devices to the ports
on the hub. In fact, you can cascade as many as 127 devices
in this way. You don't need to install any software to use
a USB hub. Some USB devices, such as some USB keyboards like
those in Lecture Theatres and most classrooms, contain a hub
so that you can plug additional USB devices into them.
Common
problems in using USB
If a
USB device doesn't work: