Micro SD memory cards are among the smallest memory cards used by most consumers. They are most prominent in cell phones but can be used in a variety of portable devices. There are several options for transferring data between such memory cards and a computer. The main difference between types of micro SD cards is the storage capacity. There is also a similar system known as micro SDHC which uses the same sized cards, though the two technologies are not always compatible.
The way that these cards are made makes them particularly suited to portable devices. They use flash memory, which means that they do not require any power to keep the information stored upon them safe. Flash is also better resistant to shocks such as being dropped than traditional hard drives. The cards have relatively quick access times, meaning it is not troublesomely slow to copy data to and from them.
A micro SD memory card can theoretically have a capacity between 16MB and 64GB. In practice, however, few cards are available commercially with capacities above 4GB. Generally cards will come in 1, 2, 4 and 8GB models.
The most common way to read memory cards that have been removed from their device is through an adaptor. This is a small casing, the size of a standard SD memory card, which has a slot for the micro SD. The adaptor itself then slots into an SD card slot on a computer. One drawback is that if the card slips out while the adaptor is in the computer, the empty adaptor is so light that it can be difficult to remove from the slot. The best way to remove it is to gently use a pair of tweezers, or — to avoid snapping off part — one pair of tweezers at each end.
It is possible to read these memory cards on computers that do not have any SD card slots. One way to do this is to insert the card into a cellphone that has a USB connection or adaptor lead. This will usually be readable directly on the computer’s operating system, though in some cases it may require dedicated software. Another option is to buy a special card reader that has a USB connection. These can be relatively cheap and can usually handle a variety of card types.
Micro SD memory cards should not be confused with micro SDHC cards. These cards are the same size and shape, but the technology they use allows capacities up to 32GB, which could increase in the future. The differing technology means some devices and computers that read micro SD cards cannot read micro SDHC cards in any form. Other devices may be able to read such cards after a firmware upgrade.