1. A display adapter for connection between a host processor and a display unit of a data processing apparatus to provide management of the display unit in response to control signals from the host processor, said display adapter comprising: a graphics processor adapted to be connected to the host processor; a video memory having at least first and second dedicated memory parts, the first memory part of said video memory being adapted to be connected to the display unit; said graphics processor being responsive to a software application and being connected to the first memory part for providing display data thereto; a logic based hardware sub-system adapted to be connected to the host processor; said logic based hardware sub-system being responsive to a hardware application and being connected to the second memory part for providing display data thereto; and means operably associated with said first and second memory parts for deriving graphics data to provide displays from the first and/or the second memory parts of said video memory for transmission to the display unit, said means for deriving graphics data comprising means for transferring data stored in the second memory part to the first memory part such that data originating from the second memory part is storable with data stored in the first memory part as combined memory data in the first memory part for application to the display unit under the control of said graphics processor.