A method and apparatus for arbitrating requests for access to a single buffer memory embedded within a disk drive in which a disk data channel is assigned a highest priority for buffer access within a queue. An arbitration cycle progressively services access requests pending within the queue, beginning with providing buffer access to the disk data channel and following with accesses to other channels during an arbitration cycle completion interval in accordance with a round-robin circular priority arrangement providing orderly access to all channels contending for memory access. At the end of completion interval, buffer access returns to the disk data channel, and thereafter, the arbitration cycle is repeated.