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About USB Technology
USB
stands for Universal Serial Bus. It is the interface between your
computer and the USB devices you plug into it. Your computer
communicates with USB devices through the USB interface.
About USB Devices
USB devices can be plugged into USB ports only, and must be
supported by USB drivers.
USB 1.1 devices operate at a maximum speed of 12 Mbps (Megabits
per second); USB 2.0 devices operate at a maximum speed of 480
Mbps.
USB 1.1 and USB 2.0 devices can be used simultaneously on the
same computer (see the next section).
Combining USB 1.1 and USB 2.0 Devices
You can use USB 1.1 and USB 2.0 hubs and devices simultaneously
on the same system, though some connection limitations exist:
■
For optimum performance, connect USB 2.0 devices and hubs to
USB 2.0 adapters. USB 2.0 devices and hubs are limited to USB
1.1 speeds if they are connected to USB 1.1 adapters.
■
USB 1.1 devices and hubs cannot operate at USB 2.0 speeds
even when connected to a USB 2.0 hub or adapter.
■
Connecting both USB 1.1 and USB 2.0 devices to the same hub
or adapter will neither slow down your USB 2.0 devices nor
speed up your USB 1.1 devices.
How Many USB Devices Can I Connect?
Technically, it is possible to connect 127 separate USB devices to
your computer. Realistically, however, USB and device limitations
mean that the maximum number of devices you can plug in at once
is less than 127. (Exact limits depend on the type of devices and
hubs you are using.)
