Earlier this month, Connectix Corporation shipped the latest version of Virtual PC, their Pentium emulation software for running Windows (and other PC operating systems) on a Power Macintosh. Virtual PC 5.0, which is available right away as a Windows 98 bundle and PC-DOS bundle, runs in both Mac OS 9 and Mac OS X, and takes advantage of multiprocessor Macs under Mac OS X, using the second processor for screen updating. The software resolves the various shortcomings seen in the Test Drive version under Mac OS X, and adds several new touches. You can use the same installation of the software and the same virtual machines in both Mac OS 9 and Mac OS X, but if you've installed it while booted into Mac OS X, you'll have to do some manual configuration.
The most innovative new feature in Virtual PC 5.0 is undoubtedly the "undoable" drive image, which enables the user to back out of a Windows session to a specific previous point in time. Basically, Virtual PC stores just the changes to the entire hard disk image in a separate file, so reverting to the original just uses that version without the changes applied to it. You can also merge changes into the hard disk image, which lets you define the state to which you'll be able to revert. This feature, which reminds us a bit of Power On Software's Rewind utility, lacks Rewind's ability to return at any moment to any arbitrary earlier point, but does offer the advantage of easily erasing a given session. We see this feature being of enormous potential value to software developers or in shared-user lab environments. One note - this feature is not password protected, so beware that a user with access to your Mac could revert your emulated PC to a previous session.
A new "Virtual Switch" feature offers networking among virtual machines under Mac OS X, allowing guest "virtual" computers two-way networking with one another, with the Mac they're running on, and even other computers on the network. The beauty of Virtual Switch networking is that it lets you simulate a small network inside your Mac. For instance, you could run Windows 2000 Server's Web server in one virtual machine and connect to it from Web browsers running on the Mac and in a Windows 98 virtual machine.
The old Shared Networking approach is still present for both Mac OS 9 and Mac OS X and remains the default because it doesn't require users to know how to configure Windows networking. There is one downside of Shared Networking, though: by default both Windows and Mac OS X run NetBIOS conflicting file sharing clients, which causes the Windows client to be disabled and generates an error message suggesting Virtual Switch networking as a solution.
I'm delighted by Virtual PC 5.0's handling of screen resolution. Unlike Virtual PC 4, which could occasionally mess up window or icon positions on the Mac side by unexpectedly changing the Mac's resolution without asking, the new version is much friendlier. Not only does it not change the Mac's resolution without your permission, for the first time it's capable of telling Windows to change its resolution on the fly. In full screen mode, this means the Windows desktop can expand to the available space (even the unusual 1152 by 768 resolution of the PowerBook G4), and when the user resizes Virtual PC's window by dragging the window's resize handle, Virtual PC tells Windows to change its resolution to match. This saves the user from having to figure out the intricacies of changing resolutions within Windows using the Display control panel.
Reports vary widely as to the performance of Virtual PC 5.0 under Mac OS X. Some folks have reported it's considerably slower - to the point of being unusable - than either Virtual PC 4.0 under Mac OS 9 or the Test Drive under Mac OS X. In my own testing, it's quite usable on my 500 MHz PowerBook G4 under Mac OS X (even more so now that I have 512 MB of RAM instead of 256), and not surprisingly, it flies on an 800 MHz dual-processor Power Mac G4 - Windows seems every bit as fluid as on a nearby 700 MHz Pentium III. Just as Apple did when it released early PowerPC versions of the Mac OS, Connectix has focused on performance of user interface items. Drawing of menus and windows, in particular, were a priority, making the interface seem, in general, snappier than in previous versions.
For best performance, of course, throw as much CPU power and RAM at Virtual PC as you can. Virtual PC 5.0 requires a PowerPC G3- or G4-based Mac (running at least at 400 MHz for Mac OS X support) with Mac OS 9.1 or later or Mac OS X 10.1 or later. RAM minimums vary from 64 MB to 256 MB depending on whether you're running in Mac OS 9 or Mac OS X and with different PC operating systems; disk space requirements vary with the PC operating system from 260 MB to 2 GB.
Other minor features in Virtual PC 5.0 include support for data DVDs and CD images, automatic sharing of removable media, access to more special Windows keys that may not exist on Macintosh keyboards, and a Get Info window that displays details about memory utilization and performance statistics. And although we couldn't confirm this easily, Virtual PC reportedly auto-localizes itself based on the selected language (English, French, German, Italian, Japanese, and Spanish) in Mac OS X.
Virtual PC 5.0 is also compatible with Microsoft's Windows XP. Connectix will be offering bundles of Virtual PC with Windows XP Home Edition in the United States, and with Windows XP Professional Edition in Japan, based on where they feel each bundle will be popular. Both operating systems will be available everywhere in the form of add-on OS packs in January of 2002; only the bundles will be market-specific.
An upgrade to Virtual PC 5.0 from an earlier version costs $80 (free to users who purchased Virtual PC 4.0 since 01-Nov-01), Virtual PC with DOS costs $100, and Virtual PC with Windows 98 costs $200. Bundled versions with Windows 2000 and Windows XP Home Edition will ship in a few weeks, as will Connectix OS Packs for users who wish to add Windows operating systems to an existing Virtual PC installation.