Editing Virtual 8086 mode (section)

==Memory addressing and interrupts==
The most common problem by running 8086 code from protected mode is [[memory addressing]] which is totally different between [[protected mode]] and [[real mode]].
As mentioned, by working under VM86 mode the [[x86 memory segmentation|segmentation]] mechanism is reconfigured to work just like under real mode, but the [[paging]] mechanism is still active, and it is transparent to the real mode code; thus, [[memory protection]] is still applicable, and so is the isolation of the address space.

When interrupts (hardware, software and int instruction) occur, the processor switches off the VM86 mode and returns to work in full protected mode to handle the interrupt. Also, before servicing the interrupt, the DS, ES, FS, and GS registers are pushed on the new stack and zeroed.