Abstract: The present invention provides a novel programmable data communications controller employed to accept data from a host computing system and for transmitting the data to a terminal designated by the host computer system. The data computer communications controller is further provided with protocols, parameters and poll tables stored in a dedicated memory of the data communications controller which enables the controller to receive data and address information from a main memory of a host computer and to reformat and pre-package the information in a protocol format block acceptable by a terminal coupled to the data communications controller. Different protocols, parameters and polls are provided in the data communications controller in the form of preprogrammed information which enables different terminals employing different protocols and protocol formats to be coupled directly to a data link interface bus without hardware modifications.