A primary design goal for MVDM and the DOS Emulation component was to provide a DOS compatible environment in which a VDM could not negatively affect other VDMs or OS/2 protected mode processes, while at the same time providing the greatest amount of free memory for DOS applications. This goal was achieved by allowing as much of the DOS Emulation code as possible to execute in protected mode, outside the VDM address space. This provides improved protection, leaves more memory available for DOS application use, and enhances overall performance.