Sanyo MM-5600

Yes it does require a certain Operating System. I had to call Sanyo, cause know one at Sprint seem to know. Sanyo informed me the the software that is in the phone is not compatible with Mac computers, she said you have to use it with PC based computers.

this phone is partially compatible Mac OS X in that, via the phone, you can read from the miniSD card, but you cannot write. ridiculous. via an external card reader and the supplied adapter, however, you can manage data on the miniSD card with OS X.

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dm