74147
10-to-4 line inverting priority encoder.

    +----------+
/A4 |1  +--+ 16| VCC
/A5 |2       15|
/A6 |3       14| Y3
/A7 |4   74  13| /A3
/A8 |5  147  12| /A2
 Y2 |6       11| /A1
 Y1 |7       10| /A9
GND |8        9| Y0
    +----------+

[This information is part of the GIICM]