The WD76C10LP is a system controller manufactured by Western Digital found in a number of 286 and 386SX PC systems including the Sega Teradrive. It provides a DRAM controller, memory map control (including A20 gate, EMS, shadow BIOS, etc.), DMA controllers, an 8254 equivalent timer and provides chip selects for some of the other peripherals.

[https://www.retrodev.com/files/WD76C10A_system_controller.pdf Datasheet]