Abbreviation for diode-transistor logic. An early form of logic family, normally produced in integrated-circuit form, whose principal switching components consist of semiconductor diodes and transistors. Each input is
fed to a diode and the output is taken from the collector of a bipolar
transistor. When all inputs are at logic 1, current can flow to the base of the
transistor so driving it into saturation. As a result the collector voltage
falls to logic 0.