ports for, you can add a hubto split the port into additional connectors. A
typical hub plugs in to the laptop at one end and offers four ports of its own.If a USB device does not work or shows erratic performance, it may not be
receiving enough power. If it can be operated with an AC adapter, try that. Or
try operating it directly from the port on the laptop or from a powered hub.When USB was first introduced, it was expected that some components, such
as external keyboards, would extend the chain with a built-in port; users have
not seen many devices with that sort of facility.Adding a USB 2.0 port to an older laptop........................................
If your laptop is an older model that does not have any USB ports, you should
be able to add two or four USB 2.0 ports by making use of a PC Card adapter.
You must be running a version of Windows that supports USB (Windows
98SE, ME, 2000, or XP) and the laptop needs to be powered by a Pentium or
equivalent processor (including Intel Celeron and AMD CPUs). Installation is
very simple; follow the manufacturer’s advice in adding necessary drivers
and other software.If your machine is so old that it doesn’t have a PC Card slot, you’re out of luck;
there is no other access to the laptop’s motherboard bus and no way to con-
vert a standard serial port to USB.Upgrading a USB 1.0 port to 2.0........................................................
If your laptop comes with USB 1.0 or 1.1 ports, you can use most USB devices
at the slower speed of the original specification; this is acceptable for some
uses such as modems, printers, NICs, and WiFi adapters. However, the slow
speed of the original USB is barely adequate for use with hard drives and
probably unacceptable with CD and DVD drives.But, as with a laptop that does not include any USB ports, you can get around
the problem by using a PC Card that adds two or four USB 2.0 ports. (You’ll
just ignore the built-in, older ports in favor of the newer ones on the card.)Devices designed for USB 2.0 are backward compatiblewith the earlier USB
1.1 specification, working at the slower speed. Cables designed for USB 1.1
should perform at USB 2.0 speeds with an advanced port; however, you need
a USB 2.0 hub in order to extend high-speed communication.246 Part IV: Failing to Communicate