Quote:
Originally Posted by zarh
Formating is just logical formating, it's not physical.
Even a physical formating do nothing as formating is just the way of build the FAT (file allocation table) for telling the computer where storing file on the disk (or card).
The only way to erase data on a sd card is to overwrite each sector.
On a hard drive you even have to overwrite several time with different patterns because with high end material you can displace the head for reading remanent magnetism of previous writing.
This can be done in white chambers and by opening the disk.
It's only done for very important data or criminal affairs as it cost a lot of money.
|
Flash memory isnt like a hard drive and it will depend on how the software makes the deletion. A simple image erase will often just take the file out by the usual hdd type method of deleting the first character and taking it out of the file allocation table. However flash memory is allocated into blocks which can be low level formatted by the card firmware when all bytes are physically set back to 255- all bits high. This is a proper deletion of data. A proper format MIGHT use this card firmware based method