The computer can’t let a week go by without giving me the finger at least once, and when I made to Friday afternoon without any incident, I felt like I could relax.
(I can imagine Bill Gates reading this while ensconced in his “as-big-as-a-shopping-mall” bungalow up in Washington and giggling furiously at that last paragraph.)
So this afternoon, feeling lucky, I pop the floppy drive in the drive so that I can have at a Word document. I had saved a document onto it earlier this morning, and was planning on adding to it during the lunch hour. Attempts to access the contents of the floppy disk were foiled by an error message window containing text that has all the explanatory power of a technical manual written in Sanskit and randomly translated by a very drunk Babelfish.
"A:/ is not accessible.
Data error (cyclic redundancy check)"
I am no dunce when it comes to computers, having been around them since I was a wee lad in the early 1980s. However, I am stumped by this pithy, and yet obscure, message. This is the second time in less than a month that I have encountered this error message, both occasions occurring on the PC I use at work. The floppy won’t work anywhere else.
On the first occasion, I finally resorted to discarding the disk (I no longer trusted it) and re-wrote the document I had on it.
This time, however, I really want to try to recover what I can from this disk. I throw myself upon the mercy of those more technically inclined than I, and beg to learn from them the answers to these questions.
What the hell is a cyclic redundancy check?
How did it happen to my floppy disk?
Hi Opal!
What can I do to recover the data?
What can I do to prevent this from happening again?
I am still at work as I write these words. When I get home, I will have Norton’s take a crack at solving this problem. In the meantime, I would appreciate any advice the Teeming Millions can offer.
In all fairness, I should have been more specific about the computer. The computer at work is the one with the attitude problem. The one at home is the very model of a well-behaved and cooperative machine.
Here’s more than you probably want to know about CRC checks.
Basically, it’s a way to detect errors in data. Extra bits (the CRC bits) are added to blocks of bits, based on a mathematical formula. In the case of your floppy, this is done as files are saved on the disk. Later, when you try to load the files, the CRC bit are recomputed based on the data from the floppy. If the recomputed CRC bits don’t match the CRC bits on the floppy, the data must be corrupted, and you’ve got a bad floppy on your hands.
If you’re getting CRC errors, you must have a bad floppy. If it happened to just data in a file, everything else might be OK. If it happened to the area on the floppy that stores the directory information, you might be in trouble.
Floppies go bad all the time due to dust, wear and tear, etc. If I’m forced to rely on a floppy for anything more than transfering data from one PC to another, I make at least three copies (using three different floppies) to lower the odds of getting burned later.
I’m afraid I can’t help with your specific problem, but generally speaking CRCs are control totals used to verify data integrity. The link below refers to them in terms of network data transmission, but I’ve also seen them used as control digits for magnetic swipe-cards (i.e. bank card numbers) and for all types of disk storage.
Most of the links I read up on seemed to suggest it was an unresolvable data error, and that the data involved is pretty much lost. Hopefully someone with a bit more experience than me can give you some better news.
One trick I’ve used to get data off a floppy is to try several different computers. Sometimes you’ll get floppies that won’t work with some floppy drives, but will work with others. Sometimes a floppy will only work with the drive that wrote to it last - there, it’s more likely that the floppy drive itself is going bad. I’ve had a couple of computers (in fact, one was a laptop) that seemed to be able to read many floppies that other computers choked on - apparently the floppy drive itself can make a difference.
If you’re going to copy to a floppy that hasn’t been recently used, it’s also not a bad idea to reformat it first, rather than simply erase it. As well as making it less likely to fail with that specific drive, if the disk is starting to go bad it will likely fail to format.
ACtually from reading your post, Shy Ghost I’d say replace your floppy drive, it sounds like it is off alignment (The floppy won’t work anywhere else.) If the floppy drive is off alignment and its heads are skewed, sorry to say, you are most likely SOL. Some drives might be able to read the data, but don’t bet on it.
Arjuna and mattk, thanks for the links. At least I know what the error means now.
yabob, that troublesome floppy is going to get re-formatted tonight, and I will test it out with some less important documents later on.
Narile, the thought of a bad floppy disk drive occurred to me when I realized that both instances of this error happened with the exact same computer at work. The one at home has never given me a problem.
As for Norton, I sicced the Utilities program on the disk, and it reported that it found an error in the file allocation table and fixed it. The floppy disk became accessible again, and I have transferred the documents off of it onto my home hard drive.
The back-up for the most important one already existed on the home hard drive, but the floppy had a version of that document that had been modified during the morning at work. I didn’t want to have to go through modifying it all over again.
I’m going to mention this incident to our resident Computer Deity at work, and see what he decides to do.