What Makes Flash Different From Disks?
Obviously, your memory cards do not store data the same way your hard drive does. The mechanical components necessary to store data magnetically simply cannot be miniaturized to the point where a hard drive can comfortably fit on your fingernail. (The smallest hard disk drive ever invented, by comparison, was about the size of a postage stamp, and could only fit about 12 gigabytes worth of data.)
When you need a lot of data in a tiny amount of space, you turn not to magnetic data storage, but to electronic data storage. This is in the form of flash memory. Every portable device today stores its data in NAND flash memory chips. NAND flash memory can fit mind-boggling amounts of data—up to 512 GB—into a single tiny microSD-sized package.
The methods for electronic data storage differ wildly from magnetic data storage. Modern NAND flash memory grew out of EEPROM, or “electrically erasable programmable read-only memory”. Unlike traditional ROM, you could erase and reprogram EEPROM using electrical current. Soon, computer scientists figured out how to erase EEPROM in chunks, instead of erasing the whole device at once. In the evolution of flash memory, one could call EEPROM the “missing link” between read-only memory and flash memory as we know it.
Because of NAND’s unique properties, the data inside the chips must constantly be rearranged and organized using special data management subroutines so that it can function more like the magnetic media we are all more familiar with.
These data management subroutines carry themselves out beneath the surface of the device, away from prying eyes. Our engineers suspected that these data management routines may have been responsible for making this SD card appear blank.