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A virtual DOS machine for PCs from Tao Software Development Company, Ramat Hasharon, Israel ( Using the built-in Virtual 8086 Mode of the x86 CPU, ExDOS enables DOS applications that used to print via the parallel port to run in Windows XP, 7 or 8 and print via USB or network connections. ExDOS fills the gap for the many people who must continue to run DOS programs in Windows PCs. See Virtual 8086 Mode.

dBASE III in Windows Vista
This dBASE order entry program running in an ExDOS virtual machine in Vista is able to print via ExDOS to the attached USB printer. DOS was written to print via the parallel port (LPT1), not USB.

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).

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