The invention proposes a system that interrupts a processing associated with an ADC having low priority when an ADC processing cannot catch up with ADR by an ADC alone that is not under execution but uses an ADC for an ADR having high priority. The MEMS scanner includes a mirror having an aspect ratio similar to the shape of the facets of a conventional rotating polygon scanner. A controller matches the sell bids with the buy bids, yielding matched buy bids and matched sell bids in response thereto so that allocations of the matched buy bids and the matched sell bids maximize a surplus of the exchange. Nested outer and inner U-shaped yokes, which may attach the gripper plate to the articulated arm, are joined by rotational joints to permit their relative rotation for reorienting the wafer carrier. A header shell is disposed around the header core and attached to the device container.