This is a hypertext (HTML) edition of this document, hosted by Tenberry Software, as a service to the Internet community.
This document is located at: http://www.tenberry.com/dpmi/index.html

A plain text (.txt) edition is available from:
ftp://ftp.tenberry.com/pub/dpmispec.zip (33K)
Or from:
ftp://x2ftp.oulu.fi:/pub/msdos/programming/specs/dpmispec.arj

Although the DPMI 1.0 specification is not of general interest -- because it was not implemented by Microsoft or by Tenberry, it is available at:
http://www.delorie.com/djgpp/doc/dpmi/

Table of Contents

• 1. Introduction
• 2. General Notes for Protected Mode Programs
  • 2.1 Virtual DOS Environments
    • 2.1.1 No Virtualization
    • 2.1.2 Partial Virtualization
    • 2.1.3 Complete Virtualization
  • 2.2 Descriptor Management
  • 2.3 Interrupt Flag Management
  • 2.4 Interrupts
    • 2.4.1 Hardware Interrupts
    • 2.4.2 Software Interrupts
  • 2.5 Virtual Memory and Page Locking
• 3. Mode and Stack Switching
  • 3.1 Stacks and Stack Switching
    • 3.1.1 Protected Mode Stack
    • 3.1.2 Locked Protected Mode Stack
    • 3.1.3 Real Mode Stack
    • 3.1.4 DPMI Host Ring 0 Stack
  • 3.2 Default Interrupt Reflection
  • 3.3 Mode Switching
  • 3.4 State Saving
• 4. Error Handling
• 5. Loading DPMI Clients and Extended Applications
  • 5.1 Obtaining the Real to Protected Mode Switch Entry Point
  • 5.2 Calling the Real to Protected Mode Switch Entry Point
• 6. Terminating A Protected Mode Program
• 7. Mode Detection
• 8. 00Xh -- Descriptor Management Services
  • 8.1 000h -- Allocate Descriptors
  • 8.2 001h -- Free Descriptor
  • 8.3 002h -- Segment to Descriptor
  • 8.4 003h -- Get Next Selector Increment Value
  • 8.5 Reserved Subfunctions
  • 8.6 006h -- Get Segment Base Address
  • 8.7 007h -- Set Segment Base Address
  • 8.8 008h -- Set Segment Limit
  • 8.9 009h -- Set Descriptor Access Rights
  • 8.10 00Ah -- Create Code Segment Alias Descriptor
  • 8.11 00Bh -- Get Descriptor
  • 8.12 00Ch -- Set Descriptor
  • 8.13 00Dh -- Allocate Specific Descriptor
• 9. 10Xh -- DOS Memory Management Services
  • 9.1 100h -- Allocate DOS Memory Block
  • 9.2 101h -- Free DOS Memory Block
  • 9.3 102h -- Resize DOS Memory Block
• 10. 20Xh -- Interrupt Services
  • 10.1 200h -- Get Real Mode Interrupt Vector
  • 10.2 201h -- Set Real Mode Interrupt Vector
  • 10.3 202h -- Get Processor Exception Handler Vector
  • 10.4 203h -- Set Processor Exception Handler Vector
  • 10.5 204h -- Get Protected Mode Interrupt Vector
  • 10.6 205h -- Set Protected Mode Interrupt Vector
• 11. 30Xh -- Translation Services
  • 11.1 300h -- Simulate Real Mode Interrupt
  • 11.2 301h -- Call Real Mode Procedure With Far Return Frame
  • 11.3 302h -- Call Real Mode Procedure With Iret Frame
  • 11.4 303h -- Allocate Real Mode Call-Back Address
  • 11.5 304h -- Free Real Mode Call-Back Address
  • 11.6 305h -- Get State Save/Restore Addresses
  • 11.7 306h -- Get Raw Mode Switch Addresses
• 12. 400h -- Get Version
• 13. 50Xh -- Memory Management Services
  • 13.1 500h -- Get Free Memory Information
  • 13.2 501h -- Allocate Memory Block
  • 13.3 502h -- Free Memory Block
  • 13.4 503h -- Resize Memory Block
• 14. 60Xh -- Page Locking Services
  • 14.1 600h -- Lock Linear Region
  • 14.2 601h -- Unlock Linear Region
  • 14.3 602h -- Mark Real Mode Region as Pageable
  • 14.4 603h -- Relock Real Mode Region
  • 14.5 604h -- Get Page Size
• 15. 70Xh -- Demand Paging Performance Tuning Services
  • 15.1 701h & 702h -- Reserved Subfunctions
  • 15.2 703h -- Mark Page as Demand Paging Candidate
  • 15.3 704h -- Discard Page Contents
• 16. 800h -- Physical Address Mapping
• 17. 90Xh -- Virtual interrupt State Functions
  • 17.1 900h -- Get and Disable Virtual Interrupt State
  • 17.2 901h -- Get and Enable Virtual Interrupt State
  • 17.3 902h -- Get Virtual Interrupt State
• 18. A00h -- Get Vendor Specific API Entry Point
• 19. B0Xh -- Debug Register Support
  • 19.1 B00h -- Set Debug Watchpoint
  • 19.2 B01h -- Clear Debug Watchpoint
  • 19.3 B02h -- Get State of Debug Watchpoint
  • 19.4 B03h -- Reset Debug Watchpoint
• 20. Other APIs
• 21. Notes For DOS Extenders
  • 21.1 Initialization of Extenders
  • 21.2 Installing API Extensions
  • 21.3 Loading the Application Program
  • 21.4 Providing API Extensions