Bus (computing)

PCI Express bus card slots (from top to bottom: x4, x16, x1 and x16), compared to a traditional 32-bit PCI bus card slot (bottom).
In computer architecture, a bus is a subsystem that transfers data between computer components inside a computer or between computers.
Early computer buses were literally parallel electrical buses with multiple connections, but the term is now used for any physical arrangement that provides the same logical functionality as a parallel electrical bus. Modern computer buses can use both parallel and bit-serial connections, and can be wired in either a multidrop (electrical parallel) or daisy chain topology, or connected by switched hubs, as in the case of USB.
Contents
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1 History
1.1 First generation
1.2 Third generation
2 Description of a bus
3 Bus topology
4 Examples of internal computer buses
4.1 Parallel
4.2 Serial
4.3 Self Repairable
5 Examples of external computer buses
5.1 Parallel
5.2 Serial
6 Examples of internal/external computer buses
7 See also
8 References
9 External links