Definition: Virtual 8086 Mode

An operational state in an Intel CPU that allows it to perform as multiple 8086/8088 CPUs, which was the architecture of the first x86 chip. Virtual 8086 Mode divides the computer into multiple address spaces and maintains registers for each one.

Starting with the 386 in 1985, Virtual 8086 Mode was created to multitask DOS "Real Mode" applications side-by-side with 32-bit Windows applications. It has been used by various virtual DOS machine implementations in Windows, including NT virtual DOS machine (NTVDM), as well as virtual DOS machines in OS/2, Unix and Linux. See virtual machine, virtual memory, NTVDM and ExDOS.

Virtual 8086 Mode in Windows Vista

This dBASE order entry program is running in ExDOS from Tao Software Development Company, which uses the Virtual 8086 Mode to run old DOS programs (see ExDOS).