Walter,
Thanks for your reply. As you know, rumors abound on the I'net. Some are true, some not. Your last post did bring out one point: not all memory cards are alike. When I think of a memory card, I think of a CompactFlash card. You are thinking of microdrives. They are two different animals. And the other memory storage devices are different than either of those two.
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Perhaps someone can suggest a good test that will show up a couple of changed bits here or there. A small change would not necessarily show
up on a photograph. A good test would probably involve writing a lot of
numbers to a card and then seeing if they change after say 10 passes
through the machine.
<SNIP>
peace
rand
Hi all,
My first thought was that since a JPEG is a compressed format, a random change to any bit (in the bits and bytes computer-talk sense) would likely break the file.
But apparently my intuition and 2 dollars will buy you a coffee at Starbuck's ;-) I just fooled around with a small JPEG, changing one bit here, and another bit there. 8 changes and each time the JPEG looked no worse for wear.
A test would be easily done--fill a small card with some sort of file (doesn't matter which). Keep a reference copy of the file. Run the card through whatever you're testing. While your there, why stop at 10 ;-) Use any number of tools to determine if the card version and the reference version are bit for bit identical or not. The best tools would be Unix-style tools like diff. One fairly point and click user-friendly text editor that comes with a "compare two files for differences between their contents" function is the freeware ConTEXT <http://www.fixedsys.com/context>.
Best to all,
Brian vdB
