Microsoft KB Archive/39565
Availability of the VCPI Specification for MS-DOS Programs ID Number: Q39565
3.x 4.00 4.01 MS-DOS
The Virtual Control Program Interface (VCPI) is a software specification for writing MS-DOS programs that run in 80286 protected mode, 80386 protected mode, or 80386 virtual 8086 mode. The specification is targeted for programs that work intimately with the 80386 microprocessor, addressing technical issues such as CPU mode switching, hardware interrupt processing, and the sharing of extended memory. Most of the VCPI calls are made through interrupt 67H, normally used exclusively by an Expanded Memory Manager (EMM).
The six initial sponsors of this specification are Phar Lap Software, Inc., of Cambridge, MA; Quarterdeck Office Systems, Inc., of Santa Monica, CA; A.I. Architects, Inc., of Cambridge, MA; Quadram, Inc., of Norcross, GA; Qualitas, Inc., of Bethesda, MD; and Rational Systems, Inc., of Natick, MA. This specification can be obtained by contacting Phar Lap Software, Inc., at the following address:
Phar Lap Software, Inc. 60 Aberdeen Avenue Cambridge, MA 02138 (617) 661-1510 Richard M. Smith, VCPI Coordinator
The eXtended Memory Specification (XMS), which was jointly developed by Microsoft Corporation, Lotus Development Corporation, Intel Corporation, and AST Research, Inc., is a separate and independent specification.