This part is a kind of semiconductor called ACS147KMSR-03.

Function of this product has Radiation Hardened 10-to-4 Line Priority Encoder.

Manufacturers : Intersil Corporation

Image and pinout :

Some of the text within the PDF file :

ACS147MS Data Sheet July 1999 File Number 4761 Radiation Hardened 10-to-4 Line Priority Encoder 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. The ACS147MS is fabricated on a CMOS Silicon on Sapphire (SOS) process, which provides an immunity to Single Event Latch-up and the capability of highly reli [ ... ]

ACS147KMSR-03 PDF Datasheet Download