These nine-input priority encoders accept data from nine active LOW inputs and provide a binary representation on the four active LOW outputs. A priority is assigned to each input so that when two or more inputs are simultaneously active, the input with the highest priority is represented on the output. Input line I9 has the highest priority. These devices provide the 10-to-4-line priority encoding function by use of the implied decimal "zero". The "zero" is encoded when all nine data inputs are HIGH, forcing all four outputs HIGH.