Virtual 8086 mode

<p>In the <a href="/facts/Intel_80386/ag5eSgWv">80386</a> <a href="/facts/Microprocessor/Fx9CaQht">microprocessor</a> and later, virtual 8086 mode (also called virtual real mode, V86-mode, or VM86) allows the execution of <a href="/facts/Real_mode/wfU8vfjn">real mode</a> applications that are <a href="/facts/Protected_mode/y5u3Gwqq">incapable of running</a> directly in <a href="/facts/Protected_mode/y5u3Gwqq">protected mode</a> while the processor is running a protected mode operating system. It is a <a href="/facts/Hardware_virtualization/6e2Bhhz2">hardware virtualization</a> technique that allowed multiple 8086 processors to be emulated by the 386 chip. It emerged from the painful experiences with the <a href="/facts/Intel_80286/rucEU93g">80286 protected mode</a>, which by itself was not suitable to run concurrent real-mode applications well. <a href="/facts/John_Crawford_(engineer)/Uk2v1FAH">John Crawford</a> developed the Virtual Mode bit at the register set, paving the way to this environment.
</p><p>VM86 mode uses a <a href="/facts/X86_memory_segmentation/7yD0VGfy">segmentation</a> 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 <a href="/facts/Paging/KR889x5k">paging</a> mechanism.
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Virtual 8086 mode open-in-new

Virtual 8086 mode