Aces High Bulletin Board
General Forums => The O' Club => Topic started by: Meatwad on September 28, 2006, 09:07:19 PM
-
I decided to reinstall operation flashpoint, but due to some scratches in the CD one of the important files cant be read during installation. Are them CD scratch removers worth it or should I just try and find another copy of the game?
-
They have glasses scratch remover "basically clear nail polish" I tried it on a pretty well scratched CD, CD is like new now. So you could try a scratch remover, what I described is my only experience though.
-
Thats a neat idea! I may run to walmart but they close in half an hour so I guess I will go tomorrow. Im too lazy to go tonight anyway
-
i would buy a new game, cause if the CD is scrathed in certain areas the binary coding will be messed up and could potentally create a virus without u noticing, but what nirvana said is true try that first
-
Originally posted by 1epic1
i would buy a new game, cause if the CD is scrathed in certain areas the binary coding will be messed up and could potentally create a virus without u noticing, but what nirvana said is true try that first
Um...wow...you hear that from a buddy in 5th grade? :huh A CRC will stop any bad code, and even if bad code were to be installed, the program just wouldn't run properly. No viruses involved.
There's two ways something can be scratched. First is the plastic scratching. This just bends the laser beam and needs to be filled or ground off. Second is the label. The label of a CD is where all the data is actually stored, so if it flakes off, the CD is a coaster. You can tell if the label's been scratched by holding it up, shiney side to you, with a light source behind it. If you see light shining through, throw out the CD.
There's two ways to fix scratched plastic, too. First is like above. Second is to use a stone to actually grind the CD down until everything is flush. You can see where I'm headed with that.
-
I'm pretty sure the label is just a label...silkscreened on after production.
The data is carried on the surface of a thin disc of mylar, which is then sandwiched between two layers of lexan. You can see the layers if you look edge on. That mylar disc is actually pressed just like old vinyl records used to be made...from a glass master.
Scratches to the lexan will interfere with the required reflection of the laser off the mylar at the center of the CD. OOZ is right that either filling or sanding out the scratches can restore readability. However, I disagree that label damage has any effect at all. If there is label damage on a CD that won't read, I'd put my money on other damage to the 'read' side of the disk. I've used the 'sanding' type with some success.
Also...viruses do not spontaneously create themselves by reading a damaged CD. It will either work, or not. They do not self-destruct. Using a damaged CD will do no harm to your computer...except maybe to lock up!
-
Originally posted by Goomba
I'm pretty sure the label is just a label...silkscreened on after production.
The data is carried on the surface of a thin disc of mylar, which is then sandwiched between two layers of lexan. You can see the layers if you look edge on. That mylar disc is actually pressed just like old vinyl records used to be made...from a glass master.
Depends on the CD. Some CD's (the cheap ones anyway) have only one plastic layer. The mylar is simply placed between the plastic disk and the label coating. A scratch on the label will then naturally ruin the CD.
-
Is that right? I didn't know that. I'll have to keep an eye out...
Learn sumpthin' new every day.
-
Seems we were both wrong. The top of the CD is coated in a reflective material that can be scratched. :)
"Compact discs are made from a 1.2 mm thick disc of very pure polycarbonate plastic. A thin layer of Super Purity Aluminium is applied (or rarely gold, used for its data longevity, such as in some limited-edition audiophile CDs) to the surface to make it reflective, which is protected by a film of lacquer. The lacquer can be printed with a label. Common printing methods for compact discs are silkscreening and offset printing.
CD data is stored as a series of tiny indentations (pits), encoded in a tightly packed spiral track of pits moulded into the top of the polycarbonate layer. The areas between pits are known as 'lands'. Each pit is approximately 100 nm deep by 500 nm wide, and varies from 850 nm to 3.5 ìm of length. The spacing between the tracks, the pitch, is 1.6 ìm. A CD is read by focusing a 780 nm wavelength semiconductor laser through the bottom of the polycarbonate layer. The difference in height between pits and lands leads to a phase difference between the light reflected from a pit and from its surrounding land. By measuring the intensity with a photodiode, one is able to read the data from the disc.
The pits and lands themselves do not directly represent the zeroes and ones of binary data. Instead, Non-return-to-zero, inverted encoding is used: a change from pit to land or land to pit indicates a one, while no change indicates a zero. This in turn is decoded by reversing the Eight-to-Fourteen Modulation used in mastering the disc, and then reversing the Cross-Interleaved Reed-Solomon Coding, finally revealing the raw audio data stored on the disc."
-
Well, I'll be damned. Guess I lost track of the latest changes to production techniques.
I'll admit, my understanding of the process was filed away in me brain some years ago, and I never went back to 'upgrade'.
If you ask me, tho...sounds cheap. I prefer the idea of the master data carrier being completely enclosed in lexan for protection, leaving a reworkable surface to improve longevity.
Ahh, well...
BTW...Thx of for the update. Now extricating foot from mouth ;-)
-
Originally posted by Goomba
If you ask me, tho...sounds cheap. I prefer the idea of the master data carrier being completely enclosed in lexan for protection, leaving a reworkable surface to improve longevity.
My DVD-Rs are like this. Regular CD-Rs have always been "scratch the label, dead CD" for me.
-
Here's something fun to try next time you burn a CD-R that doesn't work. Take a key and put a big scratch on the label. Take a can of compressed air and spray the scratched area of the CD. The entire label, and data, will come off in seconds. Shows just how fragile the data on CD's can be.
Oh, do it outside too because it makes one heck of a mess.
-
Originally posted by ChickenHawk
Oh, do it outside too because it makes one heck of a mess.
I shattered one by holding it on opposite edges and bending it out. The hard plastic flew off into the distance at great speed while the label poofed in front of me.
Poor man's Claymore and chaff, I guess. :D
-
Originally posted by 1epic1
i would buy a new game, cause if the CD is scrathed in certain areas the binary coding will be messed up and could potentally create a virus without u noticing, but what nirvana said is true try that first
Let there be life!
-
Hey guys,.. if you really want to get your cd/dvd/ etc... working again IF you have scratched the underside of the disc / plastic... then....
Take a peice of toliet paper,... moisten it with water, then apply tooth paste to the disc. Smoothly and in straight strokes at first, wipe and clean the surface. Gradually change to a buffing out of sorts while dowsing the disc with water.
Air dry (with a fan) and then presto,.. you have created a brand new smooth, clean, new disc.
Make sure that you work the plastic with even and definate strokes for about 5 minutes minumum. But then again, this varies based upon how deep the scratch/grove is.
Make sure it's dry before you put it back into the cd/dvd drive..:rolleyes: :aok
-Yeager2
-
Say what? Sounds more like a remedy if the CD has plaque buildup
-
Originally posted by OOZ662
There's two ways to fix scratched plastic, too. First is like above. Second is to use a stone to actually grind the CD down until everything is flush. You can see where I'm headed with that.
A stone takes too long
I just use one of these
(http://redmaneq.com/remco/power/grinder.jpg) :aok