Ramsey is the memory controller custom chip used in Amiga 3000 and 4000 systems, designed to manage Fast RAM access and interface with the 68030/68040 CPU. It works alongside Super DMAC to handle high-speed memory operations and 32-bit data transfers, replacing the earlier Agnus/Denise memory arbitration scheme found in lower-end models. The chip is critical for system stability and performance in professional Amiga workstations.