Actions

::Virtual 8086 mode

::concepts



{{ safesubst:#invoke:Unsubst||$N=Refimprove |date=__DATE__ |$B= {{#invoke:Message box|ambox}} }} {{#invoke:Sidebar|sidebar}}

In the 80386 microprocessor and later, virtual 8086 mode (also called virtual real mode, V86-mode or VM86) allows the execution of real mode applications that are incapable of running directly in protected mode while the processor is running a protected mode operating system. It is a hardware virtualization technique that allowed multiple 8086 processors to be emulated by the 386 chip; it emerged from the painful experiences with the 80286 protected mode, which by itself was not suitable enough to run concurrent MS-DOS applications well.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

VM86 mode uses a segmentation scheme identical to that of real mode (for compatibility reasons) which creates 20-bit linear addresses in the same manner as 20-bit physical addresses are created in real mode, but are subject to protected mode's memory paging mechanism.


Virtual 8086 mode sections
Intro  Overview  Usage   Memory addressing and interrupts   [[Virtual_8086_mode?section=_{{safesubst:#invoke:anchor|main}}Virtual_8086_mode_enhancements_(VME)_| {{safesubst:#invoke:anchor|main}}Virtual 8086 mode enhancements (VME) ]]   64-bit and VMX support   Notes  References  See also  

PREVIOUS: IntroNEXT: Overview
<<>>

Program::virtual    Which::hardware    Software::virtual    Intel::display    Windows::title    Programs::monitor

{{ safesubst:#invoke:Unsubst||$N=Refimprove |date=__DATE__ |$B= {{#invoke:Message box|ambox}} }} {{#invoke:Sidebar|sidebar}}

In the 80386 microprocessor and later, virtual 8086 mode (also called virtual real mode, V86-mode or VM86) allows the execution of real mode applications that are incapable of running directly in protected mode while the processor is running a protected mode operating system. It is a hardware virtualization technique that allowed multiple 8086 processors to be emulated by the 386 chip; it emerged from the painful experiences with the 80286 protected mode, which by itself was not suitable enough to run concurrent MS-DOS applications well.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

VM86 mode uses a segmentation scheme identical to that of real mode (for compatibility reasons) which creates 20-bit linear addresses in the same manner as 20-bit physical addresses are created in real mode, but are subject to protected mode's memory paging mechanism.


Virtual 8086 mode sections
Intro  Overview  Usage   Memory addressing and interrupts   [[Virtual_8086_mode?section=_{{safesubst:#invoke:anchor|main}}Virtual_8086_mode_enhancements_(VME)_| {{safesubst:#invoke:anchor|main}}Virtual 8086 mode enhancements (VME) ]]   64-bit and VMX support   Notes  References  See also  

PREVIOUS: IntroNEXT: Overview
<<>>