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4.27. DPlay8 - DirectPlay version 8 interface unit Table of Contents 4.28.1. DPMI Unit Types

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Table of Contents
4. Standard Units
4.28. DPMI - DOS Protected Mode Interface support unit


4.28. DPMI - DOS Protected Mode Interface support unit

Targets: MS-DOS only


The DOS Protected Mode Interface (DPMI) was defined to allow DOS programs to access the extended memory of PC architecture computers while maintaining system protection. DPMI defines a specific subset of DOS and BIOS calls that can be made by protected mode DOS programs. It also defines a new interface via software interrupt 31h that protected mode programs use to allocate memory, modify descriptors, call real mode software, etc. Any operating system that currently supports virtual DOS sessions should be capable of supporting DPMI without affecting system security. Some DPMI implementations can execute multiple protected mode programs in independent virtual machines. Thus, DPMI applications can behave exactly like any other standard DOS program and can, for example, run in the background or in a window (if the environment supports these features). Programs that run in protected mode also gain all the benefits of virtual memory and can run in 32-bit flat model if desired.

The DPMI unit intended for simplification access to DPMI functions from Pascal program.


Previous: 4.27. DPlay8 - DirectPlay version 8 interface unit To the Table of Contents Next: 4.28.1. DPMI Unit Types
4.27. DPlay8 - DirectPlay version 8 interface unit Table of Contents 4.28.1. DPMI Unit Types

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