Dotan Cohen wrote:
On 23/10/06, Carroll Grigsby <cgrigs@xxxxxxxxxxxxx> wrote:At some point in time it was reported that the inks commonly used in marking pens contained solvents that could degrade the disk material over time, which led the Sharpie people to market a special CD/DVD marker for the purpose. Yeah, I bought one.I'm not contradictining you, but recently I had a disk that was scratched on the label side and would not read. I could literally see through the scratch. I took a Black marker -Artline 70 - and coloured over the scratch. Lo and behold- I could read the disc.
This makes some sense, when you realize what is physically going on. CDROMs use forward error correction (FEC). When the number of bits in error on any given "track" are less than the critical number, then they can be corrected. What likely happened was that with a hole all the way through the metalization layer, the optics couldn't "see" the disc, and went into auto-focus, which caused the next bits not to be read due to being out of focus, effectively widening the scratch beyond the FEC capability to correct. Putting abacking on the disc may have made it so that the optics remained focussed, resulting in correctable errors.
Mike
--
p="p=%c%s%c;main(){printf(p,34,p,34);}";main(){printf(p,34,p,34);}
This message made from 100% recycled bits.
You have found the bank of Larn.
I can explain it for you, but I can't understand it for you.
I speak only for myself, and I am unanimous in that!
--
fedora-list mailing list
fedora-list@xxxxxxxxxx
To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list
