A MultiMediaCard or MMC for short, is an Integrated Circuit (IC) that is encased in a plastic covering. A MultiMediaCard functions to serve as an external storage for data, and as a mode for transferring that data from one device to another. The device must have a MultiMediaCard card slot in order to transfer the data. MMC also works well with SD (Secure Digital) writers and readers.
Standard MultiMedia Cards are 1.4 mm thick, 32 mm long, and 24 mm wide, resembling the size of a postage stamp. They weigh approximately two grams. Storage capacity can reach up to two GB, and the cards have a transfer speed of 2.5MB/s. They are almost like an SD card, but much smaller than previous models of the memory cards.
Like an SD card, MMCs have encryption feature capabilities to avoid piracy. They protect content by providing security to copyrighted materials and its distribution. Examples of such content are eBooks, music, and videos.
Storage is made more portable and convenient with these pocket size MMCs, which have become staple gadgets for mobile phones, PDAs, digital cameras, MP3/MP4 players, camcorders, eBooks, navigation systems, and personal computers. The standard MultiMediaCard was introduced to the market in 1997 by SanDisk and Siemens AG/Infineon Technologies AG. Since its release in 1997, MMC cards have revolutionized themselves into its many types and forms.
The RS-MMC or Reduced Size MultimediaCard is one example of an MultiMediaCard. It is a small and portable flash memory card that is used for mobile phones. It stores content such as pictures, music, and videos. The dimensions of an RS-MMC are: 24 mm × 18 mm × 1.4 mm.
The RS-MMC enables options for memory upgrading for RS-MMC phone owners, allowing them to transfer larger files from their phones. Most reduced size cards also come with an adapter to make them compatible with MMC-capable devices. The RS-MMC can also be used with mobile phones that come with MMC slots using the adapater.
The MMCmicro is another type of MultiMediaCard which, as its name suggests, is simple a micro version of the original MMC. Its dimensions are: 14 mm × 12 mm × 1.1 mm so it is much smaller than an RS-MMC. It is compatible with MMC, capable of supporting dual-voltage, and can be used for MMC or SD card slots using an adapter. An MMCmicro is also capable of supporting high speed.
An important reminder when using a MultiMediaCard, or any other storage device, is to never remove it while the device it is attached to is still writing to it. If you do, you run the risk of losing whatever files you are currently attempting to store on the card. In some cases, the whole MMC card may become unusable.