13
Bus-Powered Operation
Some I/O technologies, such as USB, are able to conduct
electricity as well as data to power peripheral devices. This is
referred to as "on-bus power". (A "bus" is an electronic pathway or
channel that conveys data between digital devices in the form of
electrical impulses.)
The electricity to power the device comes from the power supply
of the computer or hub to which the device is attached. As such,
a bus-powered device, such as your Toshiba Mini Hard Drive, does
not need to be plugged into an AC outlet. This allows for easier
portability, requires potentially fewer cables, and affords greater
freedom of movement.
Bus-powered operation is especially beneficial to laptop users
who often find themselves in locations where access to an AC
outlet is unavailable—and besides, who doesn’t appreciate fewer
cables?
In all but a few cases, only one USB port is needed to power your
Toshiba Drive. However, a few laptops, some hubs, and even a
small number of desktop systems, limit bus power. In these few
cases, two USB ports are required. The supplied USB cable has an
extra USB connector that can be plugged into a second USB port if
needed.
The USB electrical specifications of the myriad models of