Microsoft Virtual PC

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Virtual PC is an emulation suite for Apple Mac OS X, and a virtualization suite for Microsoft Windows operating systems. The software was originally written by Connectix, and was subsequently acquired by Microsoft.

Virtual PC emulates a standard PC and its associated hardware. Thus, it can be used to run nearly all operating systems available for the PC. However, issues can arise when trying to install uncommon operating systems that have not been specifically targeted in the development of Virtual PC.

Contents

1 Emulated environment
2 Version history
3 Intel-based Macintosh support
4 See also
5 References
6 External links

Emulated environment

Virtual PC emulates a Pentium II with MMX processor (virtualizes the host processor on Windows versions) with an Intel 440BX chipset, a standard SVGA Vesa graphics card (S3 Trio 64 PCI with 4 MByte Video RAM, adjustable in later versions), a system BIOS from American Megatrends (AMI), a Creative Labs Soundblaster 16 PnP, and a DEC 21041 (DEC 21140 in newer versions) Ethernet network card.

Not all programs are guaranteed to work because they can use undocumented features of hardware, exotic timings, or unsupported opcodes, although overall compatibility is considered excellent.

The Macintosh version of Virtual PC uses dynamic recompilation to translate the x86 code used by a standard PC into equivalent PowerPC code used by a Mac.
The Windows version of Virtual PC also uses dynamic recompilation, but only to translate kernel mode and real mode x86 code into x86 user mode code, while original user mode and virtual 8086 mode code run natively.

It also uses some guest calls traps (especially when using the guest extensions) to accelerate emulation or offer additional features, such as integration with the host environment.

Version history

The first version of Virtual PC was developed for the Macintosh and was released in June 1997. Four years later in June 2001, the first version of Virtual PC for Windows, version 4.0, was released. Connectix sold versions of Virtual PC bundled with a variety of operating systems, including many versions of Windows, OS/2, and Red Hat Linux. As it became clear that virtualization was important to the enterprise, Microsoft became interested in the sector and chose to acquire Virtual PC and an (at the time) unreleased product called "Virtual Server" from Connectix in February 2003.

Version 5.0 was ported by a third party for running with OS/2 as host. This version also included guest extensions for OS/2 guest, that can be used with Windows, OS/2 or Mac OS X hosts using Virtual PC versions 5, 6 or 7. A new version of the guest extensions were included with Virtual PC 2004.

Microsoft Virtual PC 2004 is the current version for the Windows operating system. Its equivalent on the Macintosh platform is Virtual PC for Mac version 7.

On July 12th, 2006, Microsoft released Virtual PC 2004 as a free product. Download is from http://www.microsoft.com/virtualpc

Currently, Microsoft is working on Virtual PC 2007. Virtual PC 2007 will also be free and provide support for Windows Vista and enhanced performance.

Intel-based Macintosh support

On January 18, 2006, following Apple's shift to Intel processors, Microsoft issued a statement saying that "The Mac BU recognizes the need for the product and believes it is the best virtualization solution for PowerPC users, so it is committed to providing Virtual PC to new and existing PowerPC customers. However, Microsoft is still discussing with Apple the feasibility of bringing Virtual PC for Mac to Intel-based Macs in the future and has not made any announcements about if/how the product might work on the new machines".

However, Apple has subsequently released Boot Camp which allows Windows XP to be installed on different partition of the hard drive of new Intel-based macs. This allows a user to boot into either Mac OS X or Windows, though not simultaneously. Boot Camp will ship as a standard component with the next release of Mac OS X 10.5 "Leopard", thus decreasing the need for an Intel version, as it will ship as a core part of the new OS.

There is also a competing product from Parallels, Inc. called Parallels Workstation. This application is designed to take advantage of Intel's new technology called Intel Virtualization Technology which is part of the new Intel Core processor which the majority of Apple's latest computers use. By using I-VT, it increases the performance of the guest operating system, making it more practical for regular use. Parallels Desktop also emulates newer hardware than Microsoft Virtual PC.

References

External links