Remember the problems Samsung Focus caused when you try to use a new card in its “hot-swappable” slot? Well, the things have finally started to make sense. The cards can’t be read on any other device not because they’re dead, but because they are secured on a deep system level.
Before any further explanations let’s be clear what SD stands for – Secure Digital.
When you configure a card to work with Windows Phone 7 device (which you can do officially only on AT&T’s Samsung Focus) the OS generates a secure password and stores it within the Flash memory. Then your card is being formatted and becomes password-secured. It can work only with device that has the right password stored.
Although the SD is meant to be used that way, today there are no mainstream digital devices that make use of the feature. Because of this, there are very few platforms that can recognize a secured card and format it. As it turned out, Symbian^3 is one of them.
Once formatted under WP7, the card becomes inaccessible for other devices. But Symbian^3 smartphones (Nokia N8, C7 or C6-01) can recognize and format it. You will lose the information, but you will bring the card back to life.
You can get your card back to working order but you still don’t know what card to replace it with. As I told you before, the key factor is the random access speed (or RAS, lower timing is better). It turns out that quite unexpectedly high speed class microSD cards usually have higher RAS as a performance compromise. Of course this doesn’t mean you go to the store and buy the cheapest class 2 card as they are not guaranteed to have good Random Access Speed either.
Microsoft, Samsung and AT&T have no cards in mind to recommend, since card manufacturers don’t included RAS as part of their regular data sheets. That’s the reason why Microsoft has no intend to support expandable memory – it will be a mess. It seems the Focus engineers missed that memo.
I know many of you disagree with Microsoft on cutting the expandable memory from Windows Phone 7. But they have some very good reasons – it’s better for both customization and optimization.
If you own a Focus, just stay put. Format your unreadable card (if you have one) with a Nokia phone and wait for the official list of compatible cards. Meanwhile I’m sure Samsung or any other company for that matter, won’t do the same mistake again and release a WP7 phone with an uncovered memory slot.