1
\$\begingroup\$

Flash memory is Electronically Erasable Programmable Read Only Memory. In this data is stored by the On or Off state of the transistor. Then How it is possible to recover the data stored in the device even after formatting it ?

\$\endgroup\$

1 Answer 1

3
\$\begingroup\$

Because just like with magnetic media, normal "formatting" does not actually erase the sectors used for file data until the space needs to be reused. Until that happens, it is generally possible to reconstruct most of the data structures that describe the files, which is what data recovery software is doing.

\$\endgroup\$
6
  • \$\begingroup\$ That means if data in a cell can be recovered only if new data is not written on that particular cell ? \$\endgroup\$ Apr 4, 2014 at 5:34
  • \$\begingroup\$ @tollin: exactly. \$\endgroup\$
    – Vovanium
    Apr 4, 2014 at 16:16
  • 1
    \$\begingroup\$ Note, there was a way on old magnetic disks to recover data, when they are truly formatted (by rewriting all tracks). But there was another reason: there was magnetic remanence. \$\endgroup\$
    – Vovanium
    Apr 4, 2014 at 16:20
  • 1
    \$\begingroup\$ @Vovanium: But that requires disassembling the drive and connecting the heads to special circuitry that can resolve the small residual values of remanence. \$\endgroup\$
    – Dave Tweed
    Apr 4, 2014 at 16:26
  • \$\begingroup\$ @DaveTweed floppy disks do not need disassembing but yes, still need special circuitry :) \$\endgroup\$
    – Vovanium
    Apr 4, 2014 at 16:28

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.