A missile-launching device is described which is capable of holding an arrow in a ready-to-fire position indefinitely, but which is more compact and less cumbersome than a traditional bow or crossbow. In response to detection of the occurrence of a video call event or triggering event, a video program is automatically paused. The local substrate cassette transport system transports cassettes between its substrate cassette exchange station and the stocker positions. This is accomplished by first replicating a group or records as a single logical docking object.