An IO-request processing system which is capable of reducing the maximum value of the time required until the IO request of each external device is registered. The catadioptric lens barrel structure may be used in semiconductor fabrication by placing a reticle in front of the entrance of the first lens barrels and a wafer in front of the exit of the second lens barrel. The end-effector has limiters to restrict the lateral movement of a supported wafer. The protection film can at least endure a processing temperature of solder flow. A billing system for reporting a commercial broadcast to a multiplicity of users is also disclosed. The method includes providing internal access to the fastening tool by moving a door structure and a portion of a canister to load the coil collated fasteners.