A card (originally called a solid-state floppy disk card, or SSFDC) is a memory card developed by Toshiba that uses flash memory to store data and to make it portable among devices, such as digital cameras, personal digital assistants (PDAs), and other handheld devices. At 45 X 37 mm and less than 1 mm thick (about as big as a matchbook), SmartMedia is similar in size to the CompactFlash card (although significantly thinner), but larger than the newer, postage-stamp-sized alternatives, MultiMediaCard and Secure Digital (SD card). SmartMedia cards are available with storage capacities ranging up to 128MB, with higher capacities corresponding to higher prices. Unlike CompactFlash, SmartMedia doesn't have an on-board controller. Compliant devices have a controller built into the units' slots. The main advantage that SmartMedia cards have over the other memory cards is that because they read, write, and erase memory in small blocks of data (256 or 512 bytes at a time), you can more precisely select what data you want to save. However, SmartMedia cards aren't as sturdy as the other formats, and so require more careful handling and storage.