Re:Testing an SD Card's true capacity
by avereveard on Tuesday July 11, 2017 @08:01AM
(#14743404)
that's not just bad that's intentionally evil
Re:Testing an SD Card's true capacity
by TazeTSchnitzel on Tuesday July 11, 2017 @10:35AM
(#14744494)
Then there's the fakes that modulo the address. Write beyond the end of the actual flash and you'll write over the start!
Seems like that would be the simplest way to design one. Just leave off some of the high address lines.
Re:Testing an SD Card's true capacity
by milankragujevic on Tuesday July 11, 2017 @09:33AM
(#14744000)
Could it be that a fake SD card would make all the pictures in it Black or garbled? I had that happen to me, but it was a 2GB SD card from 2007...
Re:Testing an SD Card's true capacity
by londons_explore on Wednesday July 12, 2017 @09:12AM
(#14752184)
Sure. Fakes like that have been around for almost as long as sd cards themselves.
"kind" fakes show write errors when writing data. Evil fakes just return garbage data.
I have even witnessed a few fakes which understand a fat32 filesystem and make sure the filesystem data structures and the first and last few kilobytes of every file get mapped to working flash so that a chkdsk won't pick up issues and browsing the files shows no obvious issue. Many cameras store jpeg thumbnails, and the thumbnails continue to show too.