virtual DOS machine - Computer Definition
Software that allows a 16-bit DOS application to run in a 32-bit Windows or OS/2 computer. Throughout the various versions of Windows, virtual DOS machine (VDM) implementations from Microsoft and third parties have been used. Multiple VDM (MVDM) was a virtual DOS machine that ran under the OS/2 operating system. See NTVDM, Virtual 8086 Mode and ExDOS.