[CALUG] Can Media cards have bad blocks?

[Bryan J. Smith]

I believe the slider just sends a state to the reader, not that it
can enforce anything.  What I've always disliked about NT is
that it always mounts read/write.  So any such "status bit" will
just prevent end-user operations on the device, not so much
prevent the NT kernel from corrupting it at map time.  ;)

It's like the old "tab" on floppies.  Although in this case, instead
of the drive sending the status bit to the system, the card still
does.  I may be ignorant and the device actually does prevent
the signaling to change cells, but I don't believe that's actually
the case.  I believe it's just a status bit.  That's how Windows
could easily corrupt floppies as well, even with that tab protect.

And yes, NT does a lot of really stupid things with ATA-to-CF
readers.  I've dealt with those over many years of Embedded
NT and XP.  I always and greatly preferred embedded Linux
(and even DOS) because of such.

In any case, I _never_ write/delete the SDHC device.  I always
read it, then stick it back in the camera and format.  If I don't
want to format, then I just keep shooting with all the other files
there.  I typically don't fill up the card though, and never go
more than 50%.

-- Bryan

P.S.  And yes, that's with large 16GB SDHC cards, a pair
that are nearly two years old now.  I've taken tens of thousands
of shots with my K20D body, each shot is 15MP and over 10MB
each.  I've sucked down about 400GB of shots off of my two
16GB SDHC cards, and they are still working great.

________________________________
From: Rajiv Gunja <opn.src.rocks at gmail.com>

This would explain the past corruption of my CF and SD cards on Windows. I just thought windows was crappy or I was messing something up. Good thing I have my Photo Album (digikam) on my Linux PC. 

As per the SD card being over-written, there is a small slider on the SD card which locks the SD card from being written. I use it whenever I print out pictures at a Kiosk.

Note: This months' Linux Format LXF131 has done a "Roundup" on Photo Managers. Its a good read. If anyone needs that section, I can share the PDF.