a) Any row of video crosspoints that allow selection of various sources to be selected, and the associated row of buttons for such selection.

Buses are usually associated with a given M/E or the DSK although they may be independent as in aux buses. Also, any row of video or key source selections which may or may not be selected by push buttons on a bus row. For example, key video selections on Ampex switchers appear on buses which are accessed and selected by keypads. Due to the fact that there is no associated row of buttons, this arrangement is called a “phantom bus.” b) A parallel data path in a computer.