Microsoft has quietly revealed yet another feature that is coming in Windows Phone 8.1 with Lumia Denim: The ability to download future OS updates to a microSD card instead of the phone's internal storage. As is always the case, however, this information was communicated poorly, and it's not clear yet whether this functionality will be available to non-Lumia Windows Phone handsets.
Microsoft, if you have an opening for "director of communications, Windows Phone," please let me know. You're just not doing this right.
I found out about this functionality via the sidebar in Google News, and looking at the original source—a support page at Microsoft's Mobile Devices site—one has to wonder why this wasn't more openly broadcasted. Come on, guys. This stuff is important to the few people still advocating for your mobile platforms.
Anyway, here's what we do know: The latest update to Windows Phone 8.1—8.10.14219.341, which Microsoft quite incorrectly identifies as "Denim" (which is really just a Lumia-specific firmware update that is tied to Windows Phone 8.1 Update 1)—enables support for downloading phone software updates to a microSD memory card. This makes a lot of sense since most new Windows Phone handsets provide very little internal storage, but can be expanded via microSD.
Two other things muddy the waters here, sadly.
First, it's not clear that this functionality applies to non-Lumia devices. The Microsoft Devices support page, as you might expect, only discusses Microsoft's own devices. (And by commingling the source of this new feature with a Lumia firmware update, Microsoft isn't really helping matters.)
Second, even if you do have a Lumia handset, you might not be able to use this functionality. It only applies to the Lumia 530/530 Dual SIM, 630/630 Dual SIM, 635, 636, 638, 730 Dual SIM, 735 and 830, Microsoft says. That means that many other handsets that support microSD expansion—the Lumia 520, 525, 620, 625, 720, 820, 1320 and 1520—cannot use this functionality. And if you examine these lists, you'll see some notable absences. Will the latest Lumia, the 535, support this feature? Who knows?
(On a side note, even though the Lumia 830 actually comes with both Windows Phone 8.1 and the Lumia Denim firmware, it doesn't yet support a number of features that Microsoft is promising, including this SD card OS download functionality and the Lumia Camera app, among others. Presumably, even though this phone already has Denim, it will be updated to the latest OS and firmware updates. Eventually. For the record, the OS version on my own Lumia 830 is 8.10. 14157.200, which is older the version noted above.)
Confused? Welcome to my world.