M782 Interrupt Control
From Computer History Wiki
This is a FLIP CHIP which implements the 'interrupt control' function for the UNIBUS. It was used in a large number of early PDP-11 devices which were built out of a custom backplane and a large number of Flip Chips, such as the RK11-C; some later devices which no longer used a large number of small Flip Chips (such as the TMB11) also used it.