The IBM 4020 Military Computer[1] was a Cold War era military computer.
Two of them were used in the two IBM AN/FSQ-31 SAC Data Processing Systems.
Details:[1] The instruction format includes:[1] Man-machine communications included a light-gun to indicate an area of interest on a visual display unit.
Transistors and semiconductor diodes were soldered to the outside of the Q-pac encapsulation for ease of cooling and replacement.
[1] This United States military article is a stub.