Abstract: In accordance with the present invention, an address mapper is provided between the CPU running a MS-DOS application program and a frame buffer, so as to allow the frame buffer to be mapped into the CPU address space expected by a MS-DOS application program. A write operation by the MS-DOS application program into the CPU's display address space is translated by the address mapper to be performed in the address space of the frame buffer, providing to the user the appearance as if the frame buffer is part of the CPU's address space ("Virtual MS-DOS display"). This frame buffer may have an address space larger than that used by the MS-DOS application program for writing to the display. This additional space can be allocated to other processes, which are each protected from inadvertently reading or writing into another process' allocated memory space.