Difference between MMC, SD, CF?

[taimurkhan08]

Hi!

Can someone please explain the differences between MMC, SD, and CF. And since 3650 supports MMC, can SD or CF also be used instead of MMC.

I live in Pakistan can you please tell any site from where I can get a MMC reader/writer for cheap?

[Louis6507]

Q. What is the SD Memory Card's upward compatibility with the MMC (MultiMediaCard)?

A. The SD Memory and MMC cards have the same height and width dimensions (32 mm x 24 mm), but they differ in thickness. Due to its higher capacity, the SD Memory Card, at 2.1 mm thick, is 0.7 mm thicker than the MMC card. These cards have the same contact pin layout, except that the SD Memory Card has two additional pins. When we indicate "upwardly compatible," we mean compatibility in physical specifications and lower-level logic specifications. In other words, the MMC card fits the SD Memory Card slot. Also, there is no problem with reading and writing files from/to MMC, as the SD Memory and MMC cards have the same FAT structure. But, these cards may not be compatible in the applications layer, because the applications SW specification of each card may be different


Q. Is the SD Memory Card compatible with the MMC?

A. You can transfer only non-secure data from an MMC to an SD Memory Card; you cannot transfer secure data.

There's your MMC/SD answer. SD and MMC use the same file system (FAT), but the SD has a different encoding scheme and a differnt cycle speed. Meaning it program specific.

So, the Nokia 3650 system is not compatible, but the hardware is. At least, that's what I understand.

You can only use MMC cards with the 3650. Nokia supports only up tro 128mb. You can try up to 512mb. But, Nokia does not garuntee compatibility. A few card makers do claim compatibility.

So, if you find a company with a larger card, willing to refund you if it doesn't work,...get it. But, if you like to play it safe...just get one or two 128mb MMC's.