Microsoft Corp.'s Macintosh Business Unit (MacBU) confirmed for MacCentral on Wednesday that the recently released Virtual PC 6.1 is not compatible with Apple's newest desktop machine, the Power Mac G5. Virtual PC was updated earlier this month and offered as one of the applications in Microsoft's new Professional version of Office v. X. "Virtual PC for Mac Version 6.1 will not run on the new G5 machines," MacBU Product Manager, Jessica Sommer, told MacCentral. "G5 users will get an error dialog letting them know that Virtual PC does not support the CPU in their Macintosh , The dialog allows the user to click directly to the Mactopia Web site to access support information."

Virtual PC relies on a feature in the G3 and G4 processors that is no longer present in the G5 chip. Sommer said that Microsoft is rewriting large portions of the Virtual PC code to make it compatible with the new processor. "The reason for this is that Virtual PC for Mac Version 6.1 relies on a feature of the PowerPC G3 and G4 processors called 'pseudo little-endian mode' for increased performance when emulating a Pentium processor," said Sommer. "Current versions of Virtual PC require this feature in order to function." While Sommer said compatibility with the G5 will make it into the next release of Virtual PC, no timeframe was given for the update. Microsoft acquired the Virtual PC product line, including Virtual PC for Mac, Virtual PC for Windows and Virtual Server, from Connectix Corp. in February 2003. Z4