资料来源 : pyDict

公共汽车

资料来源 : Webster's Revised Unabridged Dictionary (1913)

Bus \Bus\, n. [Abbreviated from omnibus.]
   An omnibus. [Colloq.]

资料来源 : WordNet®

bus
     n 1: a vehicle carrying many passengers; used for public
          transport; "he always rode the bus to work" [syn: {autobus},
           {coach}, {charabanc}, {double-decker}, {jitney}, {motorbus},
           {motorcoach}, {omnibus}]
     2: the topology of a network whose components are connected by
        a busbar [syn: {bus topology}]
     3: an electrical conductor that makes a common connection
        between several circuits; "the busbar in this computer can
        transmit data either way between any two components of the
        system" [syn: {busbar}]
     4: a car that is old and unreliable; "the fenders had fallen
        off that old bus" [syn: {jalopy}, {heap}]
     [also: {busses} (pl)]

bus
     v 1: send or move around by bus; "The children were bussed to
          school"
     2: ride in a bus
     3: remove used dishes from the table in restaurants
     [also: {busses} (pl)]

资料来源 : Free On-Line Dictionary of Computing

bus
     
         One of the sets of conductors (wires, PCB
        tracks or connections in an {integrated circuit}) connecting
        the various {functional units} in a computer.  There are
        busses both within the {CPU} and connecting it to external
        memory and {peripheral} devices.  The data bus, address bus
        and control signals, despite their names, really constitute a
        single bus since each is useless without the others.
     
        The width of the data bus, i.e. the number of parallel
        connectors, and its {clock rate} determine its data rate (the
        number of {bytes} per second which it can carry).  This is one
        of the factors limiting a computer's performance.  Most
        current {microprocessors} have 32-bit busses both internally
        and externally.  100 or 133 {megahertz} bus clock rates are
        common.  The bus clock is typically slower than the processor
        clock.
     
        Some processors have internal busses which are wider than
        their external busses (usually twice the width) since the
        width of the internal bus affects the speed of all operations
        and has less effect on the overall system cost than the width
        of the external bus.
     
        Various bus designs have been used in the {PC}, including
        {ISA}, {EISA}, {Micro Channel}, {VL-bus} and {PCI}.  Other
        peripheral busses are NuBus, TURBOchannel, VMEbus, MULTIBUS and
        STD bus.
     
        Some {networks} are implemented as a {bus} at the {physical
        layer}, e.g. {Ethernet} - a one-bit bus operating at 10 (or
        later 100) {megabits per second}.
     
        The term is almost certainly derived from the electrical
        engineering term "bus bar" - a substantial, rigid power supply
        conductor to which several connections are made.  This was
        once written "'bus bar" as it was a contraction of "omnibus
        bar" - a connection bar "for all", by analogy with the
        passenger omnibus - a conveyance "for all".
     
        {More on derivation
        (http://www.foldoc.org/pub/omnibus.html)}.
     
        (2000-03-20)