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etilena · Tue Dec 16, 2003 1:07 am

Is there any way to check whether the contents of a CD are all readable? Say I want to check if a CD is faulty or not without actually installing the software on it?

pez-king · Tue Dec 16, 2003 1:10 am

You could just drag everything on the disk into a folder on your hard drive. If it dosent work then somethings wrong.

meanfriend · Tue Dec 16, 2003 1:08 pm

To extend pez-king's suggestion, I believe the only way to check a cd for readability is to read the whole thing.

You could just hash or copy the whole thing and see if it chokes at any point. Not a very reliable test though as scratches may munge the data, yet error correction on your drive may still be able to 'read' it, albeit incorrectly.

The ultimate test would be to copy the CD, rip an ISO of both original and copy, and md5sum both images and compare.

Say I want to check if a CD is faulty or not without actually installing the software on it?

'faulty' cds often come from corrupted files or archives. No way to test for that unless you have the original files or another CD to compare with...

etilena · Tue Dec 16, 2003 10:56 pm

Heh.. so I reckon there's no 'easy' way to check it then.

Tue Dec 16, 2003 11:00 pm

All you can do is make a copy and hope it works right....you will not really be able to know if some of the ones and zeros got messed up. Plus CD's use 3/4's of the disc for error correction to prevent them from screwing the whole thing up.

Tue Dec 16, 2003 11:38 pm

meanfriend wrote:
Not a very reliable test though as scratches may munge the data, yet error correction on your drive may still be able to 'read' it, albeit incorrectly.

For audio CDs this is definitely true, because the error checking/correcting codes which are used on the CD are not very robust. For data CDs, a quality CD-ROM drive will report a read error if it cannot fully reconstruct the correct data.

That's not to say I haven't seen a few drives which will silently pass corrupted data back to the system... no-name generic, Acer, and Memorex to be specific.

As long as you stay away from the cheap junk drives, you can generally trust that if the drive does not report an error, the CD is most likely OK. At least for data CDs.

dolemitecomputers · Wed Dec 17, 2003 12:54 am

CD Speed maybe?

http://www.cdspeed2000.com/

Wed Dec 17, 2003 10:08 am

More or less like JBI already said, just use some some sort of imaging software to copy the CD to your HDD. Make sure you turn off *all* sorts of error-ignoring and error-correcting features you can, so that you can see every problem with your media.

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