Priority encoder in a 16-pin DIP
The SN74LS148N is a 74LS-series priority encoder that compresses eight active-low input lines into a three-bit binary output, with the highest-priority input taking precedence when multiple lines are asserted simultaneously.
Output drive and fan-out
The outputs source 400 µA and sink 8 mA — enough to drive one or two standard TTL loads directly, but a bus driver or buffer is needed if the encoder feeds a long backplane trace or multiple fan-out branches.