Quoting Gilad Ben-Yossef, from the post of Thu, 17 May: > > The tool would be useless. The underlying flash (probably NAND technology) > storage works in erase blocks sizes, each of which can be written x (for > value of x somewhere around 100,000 writes) before it becomes unreliable. > The more writes, the lesser the useful life expetency. To combat this the > Compact Flash hardware does something called uses a "wear leveling > algorithm" to virtualize the low level sectors the OS sees to a different > erase block each time.
I'm actually aware of this clever hardware saver algorithm, and still I get bad files out of the CF card every now and then, and I'd like to run a simle test. only 1 or 2 pattern writes and then reads, not 100K repeats, and I'm aware that a "bad" sector found does not guarantee it will be the same "sector" on the next run. I just want to confirm there is a bad one, and the camera is not to blame. > NAND flashes actually have a table of bad erase block not to be used. If > you can get to the NAND tables via the CF interface (doubt it, but who > knows?) actually, there are rescue programs that resque images even from sectors that were "written over" in flash cards, I'm quite positive they can selectively acces the real information about which hardware block of flash served as which "logical" sector in the past, and it manages to rescue quite a lot. pretty cool. the only places I've seen it though are in windows freeware, so It may not be an open API. -- Something to pick you up Ira Abramov http://ira.abramov.org/email/ ================================================================= To unsubscribe, send mail to [EMAIL PROTECTED] with the word "unsubscribe" in the message body, e.g., run the command echo unsubscribe | mail [EMAIL PROTECTED]
