Abstract: The present structure is an interchangeable interface circuit card which per se includes: circuitry which is responsive to being addressed in accordance with its physical location; circuitry to generate signals which identify the circuit being addressed and the peripheral to which it is connected; and circuitry to generate signals which effect a diagnostic routine applicable to at least some of the interchangeable interface circuits on the circuit card being addressed. In addition the present structure includes priority circuitry which operates in conjunction with a data handling system to assert a priority value assigned to the interchangeable interface circuit card and which, based on that priority, determines which one of a number of interchangeable interface circuit cards will be permitted to control a common data path.

Abstract: The present disclosure is directed to an arrangement whereby any one of a plurality of different or similar interface circuit cards can be located into any one of a number of slots or holding means of a data processing system, without preassignment thereto, and whereby each of the interface circuit cards will generate its own diagnostic routine signals and signals representing its own identification, the latter signals being used in a self-configuration operation of the system and whereby an arbiter means is employed to determine, among the plurality of interface circuits, which has the highest priority in the event more than one of said interface circuits is requesting the use of a common data flow path.