In a computer or on a network, a bus
is a transmission path on which
signal s are dropped off or picked
up at every device attached to the
line. Only devices addressed by the
signals pay attention to them; the
others discard the signals.
According to Winn L. Rosch, the term
derives from its similarity to
autobuses that stop at every town or
block to drop off or take on riders
In general, the term is used in two
somewhat different contexts:
(1) A bus is a network topology or
circuit arrangement in which all
devices are attached to a line
directly and all signals pass
through each of the devices. Each
device has a unique identity and can
recognize those signals intended for
it.
(2) In a computer, a bus is the data
path on the computer's motherboard
that interconnects the
microprocessor with attachments to
the motherboard in expansion slots
(such as hard disk drives, CD-ROM
drives, and graphics adapters).
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