1. A method of selectively connecting one of a plurality of device controllers with an input/output channel of a processor module in accordance with a predetermined priority scheme in a system of the kind in which a plurality of device controllers are connected to an input/output channel comprising a multiple bit data bus and can each assert a reconnect or an interrupt request signal to the input/output channel simultaneously with the assertion of reconnect or interrupt request signals from the other device controllers, said method comprising, determining which device controllers are asserting requests to the input/output channel, selecting a particular device controller by the input/output channel in accordance with the predetermined priority scheme, connecting the device controllers to the input/output channel in a star poll connection so that each device controller is independently connected to the input/output channel and any number of device controllers can fail or be powered off without affecting the polling of the other device controllers and wherein the star poll connection comprises a single interrupt line connected to the device controllers for transmitting an interrupt request signal from a device controller to the input/output channel and the data bus is a multiline bi-directional data bus for transmitting individual addresses on ones of the data lines associated with a related individual ones of the device controllers for addressing the device controllers so that the individual lines of the data bus transmit both data and addresses, performing data transfer between the input/output channel and the selected device controller, and disconnecting the selected device controller at the end of the data transfer.