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In a wired-and, a resistor is tied to VCC. The output is the bottom of the resistor. It will normally be high. But if you connect a transistor to the resistor and ground, and activate it, the output will go low. Now, just keep adding transistors. See image below.
This is why outputs are specified open-collector, so they can be hooked up this way. All have to turn off to for the output to be high.
wired AND is a connection method in which the output of two AND gates is connected together directly and this connection acts like a AND gate.... for details see morris mano - digital design... this works only in the case of open collector type digital circuits because when the output of the two AND gates are different one of them has to be forced to zero...