Microsoft quietly changed the specifications for devices running its Windows 10 Mobile operating system by upping the allowable maximum screen size to under nine inches.

It's not clear from Microsoft's MSDN page when the company made this change, which I saw in a May 22 report from MSPowerUser.com (and is originally from NokiaPowerUser).

Until some point recently, the maximum allowable screen size for Windows 10 Mobile devices was 7.99 inches.

Microsoft also is allowing devices with screens as small as 7 inches to run the Windows 10 desktop operating system. The previous low-end limit for Windows 10 desktop devices was 8 inches for the majority of devices, though tablets running Windows 10 Pro (only) were allowed previously to be as small as 7 inches.

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The change in screen sizes is interesting, given speculation by some of us Microsoft watchers that the company is working on some kind of new Microsoft-branded Surface mobile device, running Windows 10 Mobile, that may debut next year. The number nine also is noteworthy in that Microsoft said back in 2014 that it would make Windows 10 free to OEMs building tablets and phones with screen sizes under nine inches.

I'm curious whether Microsoft also is planning to allow OEMs to run Windows 10 Mobile on Intel-based devices, moving forward. Last year, when Microsoft was working on Windows 10 Mobile, the company specified that Windows 10 Mobile would work on both Intel- and ARM-small tablets.

Currently, the Windows 10 Mobile device spec list only mentions ARM-based devices as supported to run Windows 10 Mobile. Intel recently announced it was backing away, at least temporarily, from the mobile phone/tablet market.

I've got questions into Microsoft about its spec changes and will update this post with more details if and when I hear back.