The Dutch website Tweakers.net managed to get their hands on some internal Microsoft documents that outline the OS architecture – including memory, graphics and storage details.

To start with, Windows phone 7 is going to be a 32-bit, dual-layer (User space and Kernel space) OS. There’s no surprise here – with Microsoft’s rigid minimum chassis requirements for Windows Phone 7 there’s no need for any kind of hardware layer, and I don’t see anything shocking in the individual components of the Kernel space. Everything in the Kernel interacts directly with the core components of the Shell and driver services, and then on to your applications. This general layout is quite similar to Windows Mobile 6.x.

Memory on Windows Phone 7 devices will be organized differently. Like Windows Mobile 6.x, up to 2GB will be available to each layer but, unlike WM6, the non-kernel memory is limited to nice, big 1GB per application instead of a measly 32MB on 6.x. This means much more memory available to apps and – ironically – better multitasking (even though multitasking is gone in WP7).

File storage is taken care of on Windows Phone 7 using IMGFS and TexFAT, for system files and user storage respectively. The user storage will employ a Unified Storage System structure, which means users will see a unified list of files, regardless of their actual storage location.

Graphics is taken care of on the Microsoft side by a generic 2D graphics runtime and a Direct3D 11 runtime for 3D graphics. This uses the same Direct3D11-on-top-of-10-on-top-of-9 scheme we’ve seen on the desktop version of Windows 7 and leaves actual 2D and 3D drivers to the manufacturer.

So is this good or bad?

Nothing here stopped me in my tracks, but a few things are of note:

• The graphics driver situation might be a source for concern, as manufacturers aren’t always known for the best drivers, but that could be an area where some OEMs distinguish themselves.
• Nice to see up to 1GB of memory for running applications, this should make all kinds of sweet apps and games possible. Still too bad Microsoft doesn’t use this new memory schema to provide multitasking though…
• I’m interested to see how the Unified Storage System works. One of the perks of the TexFAT file system is that the system can treat multiple locations as the same, thus enabling this USS… could simplify storage of synchronized pics and videos, etc.

The document that Tweakers.net nabbed was clearly marked “revision 3.0” and makes no bones: “The Architecture for Windows Phone OS 7.0 describers features that are subject to change, and should therefore be considered preliminary.” Still, a little fodder is always fun.

Check out these other three posts for more details from the leaked Microsoft documents:

• Windows Phone 7 Update Procedure Detailed in Leaked Docs
• Details on Windows Phone 7 Customization from Leaked Microsoft Docs
• A Bit More Detail on Windows Phone 7 Hardware Requirements

[via]