cyclic redundancy

Cam · 12-15-2002, 03:29 PM

I work in the computer lab on campus and our labs switched over to Windows XP Pro this semester. I've had 3-4 people come in to print stuff they saved on a floppy at home who have tried to access their disk through Word and get a "disk error (cyclic redundancy)" When I try to open the disk using explorer the disk comes up as being unformatted.

All of the people who have gotten this error have been able to access their disk at home where the majority of them have informed me they use windows 98 or ME. I can't figure it out, and sadly my boss just doesn't give a shit so nobody working in tech support is going to attempt to figure this out.

I've done some googling and the only explanation I can find is that it's caused by a bad floppy, or bad drive, but if they can access the files at home, and other disks work fine in the drive neither of these explanations make any sense. If anyone has any ideas they would like to share they would be welcome.

Undertoad · 12-15-2002, 03:52 PM

Is it happening on all the XP machines or only on one of them?

Cam · 12-15-2002, 03:59 PM

It seems to happen on all of them, I've tried on three or four and keep getting the same error. They are all ghosted with the same image frequently too. We used to have 98 on the computer usworkers use, and I could open their files there. Now we have XP and that doesn't work anymore.

jaguar · 12-15-2002, 04:35 PM

Yea CRC are usually screwed floppies or drives. Not sure how 98 would take it if XP decided to format them NTFS though..
Which i now it can do, why, i have no idea, on the other hand its XP, it does many things which defy logic. Drives issue maybe? i know it sounds odd by maybe the floppy drive on the image has an error or is corrupt.

juju · 12-15-2002, 05:08 PM

Windows 98 machines can't read NTFS.

Cam · 12-15-2002, 06:35 PM

Quote:

i know it sounds odd by maybe the floppy drive on the image has an error or is corrupt.

Yeah that's kind of what I got to thinking which means it won't be fixed until summer, somehow my managers seem to think creating an image is a god awful thing, and when they do take the time to do it they do a really shitty job. the clocks are all set an hour ahead on all the machines for christs sake.

MaggieL · 12-15-2002, 08:31 PM

Quote:

Originally posted by Cam
...but if they can access the files at home, and other disks work fine in the drive neither of these explanations make any sense. If anyone has any ideas they would like to share they would be welcome.

CRC (cyclic redundancy check) is a checksum stored with each sector of data on the disk; if what is read back isn't quite what was originally writtin, the CRC checksum will come up bad.

What can happen with worn-out diskette drives is head-positioning errors that result in tracks being written in not quite the right place. Of course. they may read-back fine on the drive on which they were created, but fail in a flaky fashion on other drives that are either within-spec or out-of-spec in some way different from the bad drive.

Worn heads can also cause weak writing or reading, with a more unifiormly bad result.

headsplice · 12-16-2002, 01:00 PM

Have you checked the logs of the machines to see exactly what the error code is? That would help.

Cam · 12-16-2002, 01:38 PM

ahh good idea, I'll do that next time the error shows up, which is part of the problem since most people just take there disks home, I can't play and figure it out. I'm going to try and hunt down a couple other 98 computers and make a new disk and see if it comes up after christmas break.

headsplice · 12-16-2002, 02:17 PM

If you get a specific error code out of the logs, go here and select the advanced search. You can search by error code iand by platform, so hopefully someone else has run into the same problem. Good luck!

Cam · 12-16-2002, 02:34 PM

Thanks All

tw · 12-17-2002, 08:41 AM

There are so many issues involved in the CRC error that I am only going to touch on a few possibilities. Of course the most basic problem is diskette head alignment problems. Then a conflict using interrupts on the diskette controller since Windows 9x really did not use interrupts. Timing problems because floppies are expected to be ready to read data after a certain latency and those floppy drives are too slow. Timing problems that would only appear on how certain diskettes are formatted. Diskettes formatted by another machine - not from the factory. Such diskettes would not always format properly on all machines but may format on a few machines meaning the diskette is defective.

Information to collect - manufacturer of home and work diskette drives. Are any of these diskettes single sided? Will diskettes checkout using Scandisk at home after having been accessed at work? What does Chkdsk in XP say? Just a few ideas from a very long list of possibilities.

12-15-2002, 03:29 PM	#1
Cam dripping with ignorance Join Date: Oct 2002 Location: Grand Forks ND Posts: 642	cyclic redundancy I work in the computer lab on campus and our labs switched over to Windows XP Pro this semester. I've had 3-4 people come in to print stuff they saved on a floppy at home who have tried to access their disk through Word and get a "disk error (cyclic redundancy)" When I try to open the disk using explorer the disk comes up as being unformatted. All of the people who have gotten this error have been able to access their disk at home where the majority of them have informed me they use windows 98 or ME. I can't figure it out, and sadly my boss just doesn't give a shit so nobody working in tech support is going to attempt to figure this out. I've done some googling and the only explanation I can find is that it's caused by a bad floppy, or bad drive, but if they can access the files at home, and other disks work fine in the drive neither of these explanations make any sense. If anyone has any ideas they would like to share they would be welcome. __________________ After the seventh beer I generally try and stay away from the keyboard, I apologize for what happens when I fail.

12-15-2002, 03:59 PM	#3
Cam dripping with ignorance Join Date: Oct 2002 Location: Grand Forks ND Posts: 642	It seems to happen on all of them, I've tried on three or four and keep getting the same error. They are all ghosted with the same image frequently too. We used to have 98 on the computer usworkers use, and I could open their files there. Now we have XP and that doesn't work anymore. __________________ After the seventh beer I generally try and stay away from the keyboard, I apologize for what happens when I fail.

12-15-2002, 04:35 PM	#4
jaguar whig Join Date: Apr 2001 Posts: 5,075	Yea CRC are usually screwed floppies or drives. Not sure how 98 would take it if XP decided to format them NTFS though.. Which i now it can do, why, i have no idea, on the other hand its XP, it does many things which defy logic. Drives issue maybe? i know it sounds odd by maybe the floppy drive on the image has an error or is corrupt. __________________ Good friends, good books and a sleepy conscience: this is the ideal life. - Twain

12-16-2002, 01:00 PM	#8
headsplice Relaxed Join Date: Jul 2002 Location: Minneapolis Posts: 676	Have you checked the logs of the machines to see exactly what the error code is? That would help. __________________ Don't Panic

12-16-2002, 01:38 PM	#9
Cam dripping with ignorance Join Date: Oct 2002 Location: Grand Forks ND Posts: 642	ahh good idea, I'll do that next time the error shows up, which is part of the problem since most people just take there disks home, I can't play and figure it out. I'm going to try and hunt down a couple other 98 computers and make a new disk and see if it comes up after christmas break. __________________ After the seventh beer I generally try and stay away from the keyboard, I apologize for what happens when I fail.

12-15-2002, 03:52 PM	#2
Undertoad Radical Centrist Join Date: Jan 2001 Location: Cottage of Prussia Posts: 31,423	Is it happening on all the XP machines or only on one of them?

12-15-2002, 05:08 PM	#5
juju no one of consequence Join Date: Jun 2001 Location: Arkansas Posts: 2,839	Windows 98 machines can't read NTFS.

12-16-2002, 02:17 PM	#10
headsplice Relaxed Join Date: Jul 2002 Location: Minneapolis Posts: 676	If you get a specific error code out of the logs, go here and select the advanced search. You can search by error code iand by platform, so hopefully someone else has run into the same problem. Good luck! __________________ Don't Panic

12-16-2002, 02:34 PM	#11
Cam dripping with ignorance Join Date: Oct 2002 Location: Grand Forks ND Posts: 642	Thanks All __________________ After the seventh beer I generally try and stay away from the keyboard, I apologize for what happens when I fail.

12-17-2002, 08:41 AM	#12
tw Read? I only know how to write. Join Date: Jan 2001 Posts: 11,933	There are so many issues involved in the CRC error that I am only going to touch on a few possibilities. Of course the most basic problem is diskette head alignment problems. Then a conflict using interrupts on the diskette controller since Windows 9x really did not use interrupts. Timing problems because floppies are expected to be ready to read data after a certain latency and those floppy drives are too slow. Timing problems that would only appear on how certain diskettes are formatted. Diskettes formatted by another machine - not from the factory. Such diskettes would not always format properly on all machines but may format on a few machines meaning the diskette is defective. Information to collect - manufacturer of home and work diskette drives. Are any of these diskettes single sided? Will diskettes checkout using Scandisk at home after having been accessed at work? What does Chkdsk in XP say? Just a few ideas from a very long list of possibilities.

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