Cyclic Redundancy Check

[roshan]

When I try to install games from some old and scratched cds to my new laptop, i keep getting these cyclic redundancy check errors(i have a dvd writer multi drive). However, the cds work fine in other pcs. Is there any way that I can fix these problems or do i need to buy a regular cd player to be able to play the cds?

[@\NightandtheShape/@]

Not sure how you can fix it but essencially what it means is your reader isn't reading the cd correctly and it's basically farting and saying there is data missing. I suppose you could try some kinda virtual drive, and litterally copy the CD to it. Not sure how that would turn out.

 

Or you could read the CD from the the drive that reads it, and then network it to your laptop HD. That wouldn't be a fun job... Basically what I'd do is make a copy on a PC that can read it, and see how you fair with that.

[roshan]

Damn. I think Ill have to buy an external cd rom drive for my laptop or something so that i can run the cds, or burn new copies of them.

[@\NightandtheShape/@]

Damn. I think Ill have to buy an external cd rom drive for my laptop or something so that i can run the cds, or burn new copies of them.

<{POST_SNAPBACK}>

 

Sounds to me like the CD's are hammered. No need to shell out serious money, just burn a copy somewhere else if you can, it's certainly not the reader though i imagine the laser should be finer, thusly the problem reading scratched CD's.

[taks]

a cyclic redundancy check (CRC) (edit: oops, wrong definition, i'm typing ahead of my thinking)... correct definition: a CRC is generated by sending a data stream, bitwise, through a linear feedback shift register (LFSR) configured with certain tap outputs XOR'd together. once the last bit is stuffed into the pipe is the CRC value, attached to the end of the data stream as a word (two bytes, perhaps, for a 16-bit CRC). it is a very simple method of detecting, but not correcting, possible errors. CRCs have a very low probability of "missing" an error. in other words, if you have a bad bit, the CRC may not match and the data essentially gets dropped.

 

CDs go bad over time (particularly older CDs as the materials were not of the same quality as today's), and even very small scratches may result in CRC errors. however, i have also seen rather deep scratches result in zero errors...

 

taks

[roshan]

Thats horrible. But it works on some cd roms though, and doesnt work in others. Is there any way i can disable this cyclic redundancy check bs?

stuff? Its making my life miserable - nothing works on this crappy dvd writer.

[corganis]

Yeah, I get the same error, and the fix segested in the problems solutions thread didnt work.

[RiK]

Thats horrible. But it works on some cd roms though, and doesnt work in others. Is there any way i can disable this cyclic redundancy check bs?

stuff? Its making my life miserable - nothing works on this crappy dvd writer.

<{POST_SNAPBACK}>

 

No, you can't turn it off.

Try the cd's on another drive/computer. If they are ok, just make some backups; if not.. well... External drives are becoming cheaper every month.

[taks]

Is there any way i can disable this cyclic redundancy check bs?

<{POST_SNAPBACK}>

no, you can't. not without changing the firmware in the drive. however, the CRC check is there for your protection. if you get a CRC error, the corruption is possibly enough to cause massive problems with the file or program you're trying to read. corrupted data in a program can be much worse than a typical bug in a program. system stability problems could easily be expected.

 

taks