Virtual 8086 mode
From Free net encyclopedia
In the 80386 and later, Virtual 8086 mode, also called virtual real mode, allows the execution of real mode applications that violated the rules mentioned here under the control of a protected mode operating system.
It used the real mode way for segmentation, but used the 20-bit (actually 21-bit) address resulting from it as a linear address, so it is subject to paging.
It is used to execute DOS programs in Microsoft Windows/386 and Windows 3.x and Windows 9x and Windows Me and OS/2 2.x and later through Virtual DOS machines, in SCO UNIX through Merge and in Linux through dosemu.
Protected mode DOS programs, either 16 or 32-bit, do not execute in virtual 8086 mode, but rather in user mode (as long as they are DPMI compatible), so the above emulators do actually more than just supporting the virtual 8086 mode.
See also
- Real mode — Unreal mode — Virtual 8086 mode — Protected mode — Long mode
- IA-32
- x86
- x86 assembly language
