Microsoft announced its Windows Phone 7 (right), to be available on phones by this year's holiday season, at last month's Mobile World Congress (MWC) in Barcelona. The operating system will feature dynamically updated "live tiles" along with more detailed pages called "hubs," which connect to Web services, applications, contacts and other items, according to Microsoft.

As for entertainment, "every Windows Phone 7 will be a Zune," Microsoft officials said at the time. Devices will include FM receivers, and users will be able to employ Zune software to transfer music to and from a PC. Photos will now be automatically synchronized to Internet-based cloud storage, while ActiveSync and Windows Mobile Device Center will no longer be employed, the company added.

Earlier this month, Microsoft disappointed some by announcing that Windows Phone 7 devices will not run software written for Windows Mobile. As the company explained, developers will need to create software for the phones using Microsoft's Silverlight or XNA. (Touted as "industry-leading software, services, resources, and communities," XNA is a rather sprawling acronym -- "X" stands for "A cross section of software tools and technologies for Windows and Xbox 360, "N" stands for "Next-gen," and "A" stands for "Architecture.")

In conjunction with this week's Game Developer Conference (GDC) in San Francisco, and next week's Microsoft-run MIX10 conference in Las Vegas, company officials have begun to provide more details. Regarding hardware, all initial Windows Phone 7 devices will sport 800 x 480 pixel touchscreens, according to a blog posting by Microsoft programmer Shawn Hargreaves.

Hargreaves notes that some future Windows Phone 7 devices will have 480 x 320 touchscreens instead, and appears to suggest that programmers boost their games' performance by using that lower resolution, since "it can be a challenge for intensive 3D games to render so much data at a good framerate." Phones will feature built-in image scalers that will stretch games to fill their displays when necessary, without consuming any GPU (graphics processing unit) resources, he adds.

While the Qualcomm Snapdragon chipset thought to be at the heart of Windows Phone 7 devices includes a unified pixel and vertex shader pipeline, the operating system will not support programmable shaders in its first release, according to Hargreaves. He writes:

"Instead of programmable shaders, we augmented the existing BasicEffect with four new configurable effects: SkinnedEffect, EnvironmentMapEffect, DualTextureEffect, and AlphaTestEffect. These are designed to run efficiently on the mobile GPU hardware, and I think do a good job of providing enough flexibility for developers to create awesome looking games, while also meeting our goals of being able to ship a robust and well tested product on schedule."

According to Microsoft, game development for Windows Phone 7 will rely on version 4.0 of XNA Game Studio. This managed code platform was first released in December 2006 and has been touted as a platform allowing development of games that will work on Windows PCs, the Xbox 360, and the Zune HD. Existing APIs for such things as multitouch and the Zune media client are maintained, and developers will be able to adapt games built on previous versions of XNA Game Studio without extensive re-coding, the company promises.

Sample Windows Phone 7 Games: The Harvest by LumaArcade (top) andBattle Punks by Garage Games/Gravity Bear
Source: Microsoft

However, a posting by Microsoft programmer Michael Klucher suggests that the Zune HD, released only last September, has been orphaned. He writes, "Development for the Zune and Zune HD will continue to exist in XNA Game Studio 3.1, however, in XNA Game Studio 4.0, we're encouraging you to migrate your games over to the Windows Phone 7 Series platform." As a result, while some games may be back-ported, the Zune HD will apparently be unable to run the mobile Xbox Live games touted by Microsoft for its new Windows phones.

According to a separate posting by Microsoft watcher Mary Jo Foley, Microsoft may be planning to release a "Zune HD2" later this year that, unlike the first Zune HD, will be able to run all the software written for Windows Phone 7 devices without modification. The WiFi-only device would bear the same relationship to Windows Phone 7 handsets that Apple's iPod Touch does to its iPhone, she suggests.

Finally, Microsoft said at MWC that when Windows Phone 7 devices launch later this year, they would not be compatible with Adobe's Flash multimedia software. However, unlike Apple, Microsoft "has no objection to Adobe," company CEO Steve Ballmer quipped at the time.

This week, Adobe confirmed that Flash is indeed on its way to Windows Phone 7. Mike Chambers, Adobes principal product manager for developer relations for the Flash platform, blogged, "Adobe and Microsoft are working together to bring Flash Player 10.1 to Internet Explorer Mobile on Windows Phone 7 Series. I don't have an ETA or other specifics right now, but it is something that both Adobe and Microsoft are working closely together on."

Further information

The Shawn Hargreaves blog posting mentioned above may be found here, while Michael Klucher's posting can be found here.

Mike Chambers' posting on behalf of Adobe may be found here.

Mary Jo Foley's posting regarding the rumored Zune HD2 may be found here.

Details of the MIX conference, some of which will be webcast live, may be found here.

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