DOS Protected Mode Interface

In computing, the DOS Protected Mode Interface (DPMI) is a specification introduced in 1989 which allows a DOS program to run in protected mode, giving access to many features of the new PC processors of the time not available in real mode. It was initially developed by Microsoft for Windows 3.0, although Microsoft later turned control of the specification over to an industry committee with open membership. Almost all DOS extenders are based on DPMI and allow DOS programs to address all memory available in the PC and to run in protected mode (mostly in ring 3, least privileged).