A multiprocessor system comprises concurrent display of video data reflecting the operation of two processors in discrete portions of a single display screen with a user interface adapted for interaction with both processors. One processor controls the entire display while allocating a portion of the display screen for the use of the other processor which processor emulates a target processor system, for example, the IBM PC. A user interface is represented on the display screen in the form of metaphoric objects, called icons, with which the user can interact by changing the input focus to a designated object by visually pointed to it via the input means, which thereafter permits manipulation of the designated object or interaction with data input/output relative to the designated object. This input means is also used to initially change the input focus to either the allocated emulating processor screen portion or to the remaining portion of the central processor display screen prior to interaction with the metaphoric objects in a selected screen portion, the change of the input focus causing subsequent user input via the input means to be directed to the selected screen portion until interrupted by a change in focus input to the other of the screen portions by the user via the input means. An icon may be a representation of a virtual object, such as a virtual floppy disk, that is accessible in either the host system world or in the emulating processor world even through the virtual floppy disk may have a filing system alien to the host system world.