in decision block 518 again if the arbcrit signal becomes true at any time while another bus master device of first priority is in control of the bus operation proceeds to block 520 wherein operation of the bus master device of first priority is suspended and operation flows to blocks 504 510 assuming that the arbcrit signal has not been asserted in block 518 operation flows to decision block 522 wherein the predetermined limited period of time during which a bus master device of first priority can execute control of the system bus is monitored provided this period has not expired monitoring of the arbcrit signal and the predetermined limited period of time continue however once the predetermined limited period of time has expired operation of the bus master device of first priority currently in control of the system bus is terminated and operation returns to block 524 wherein the next bus master device of first priority is selected pursuant to the equal access arbitration scheme those skilled in the art will appreciate that the present invention is not limited to the exemplary embodiments described above for example those skilled in the art will appreciate that the bus master device of second priority need not include a separate request line and a separate arbitration critical line but that an arbitration critical line alone can be used in this case the arbcrit signal can both serve as a request signal and as an inhibit signal for inhibiting the limited period of time afforded the bus master devices.