A wired logic connection is a

logic gate A logic gate is an idealized or physical device implementing a Boolean function, a logical operation performed on one or more binary inputs that produces a single binary output. Depending on the context, the term may refer to an ideal logic ga ...

that implements

boolean algebra (logic) In mathematics and mathematical logic, Boolean algebra is a branch of algebra. It differs from elementary algebra in two ways. First, the values of the variables are the truth values ''true'' and ''false'', usually denoted 1 and 0, whereas in ...

using only passive components such as diodes and resistors. A wired logic connection can create an AND or an

OR gate The OR gate is a digital logic gate that implements logical disjunction. The OR gate returns true if either or both of its inputs are true; otherwise it returns false. The input and output states are normally represented by different voltage lev ...

. The limitations are the inability to create a NOT gate and the lack of level restoration.

The wired AND connection

The wired AND connection is a form of

AND gate The AND gate is a basic digital logic gate that implements logical conjunction (∧) from mathematical logic AND gate behaves according to the truth table. A HIGH output (1) results only if all the inputs to the AND gate are HIGH (1). If not all ...

. It uses a pull up resistor and one diode per input to create this function. In this example diagram 5V is considered logic HIGH (TRUE), and 0V is LOW (FALSE). The voltage on ''output C'' will be HIGH only when ''input sources A'' AND ''B'' are HIGH. If either input is LOW, output C will measure LOW. Usefully, an AND gate can have an arbitrary number of inputs. The behaviour of logic gates is often described by a

truth table A truth table is a mathematical table used in logic—specifically in connection with Boolean algebra (logic), Boolean algebra, boolean functions, and propositional calculus—which sets out the functional values of logical expression (mathematics) ...

:M. Morris Mano, ''Digital Logic and Computer Design'', Prentice-Hall, 1979 , page 571 The LOW state output voltage C will be approx 0.5V, due to the diodes' forward voltage. Output C would be approx 0.1V if trans