Posts Tagged ‘DVDs’

Tech Tips… kinda

Thursday, July 10th, 2008

Here’s another edition of Tech Tips! Although in this case, it’s not so much tips as warnings.  About a few things… read between the lines.  Or not.

Tip #1: Never let cybr have free time with a razor knife and spare junk laying about.

This, you would think, would just be common sense.  However time and time again I find myself with a box cutter or retractable razor knife and idle time while software is installing.  It seems somethings never change.

Tip #2: If cybr has a knife, don’t let him sort through CDs.  At least not unsupervised.

Again, this should just be common sense, but I have an office and it was an unusually quiet morning.  I was sorting through all the old CDs and DVDs laying about the office and throwing out all the discs that have never and will never be used.  Of course, I don’t want people fishing them out of the trash and using them illegally.  Because I’m against illegal software and stuff.  Yeah.  So I was using the retractable knife to cut grooves into each disc I was trashing.  But then I started to get bored with that and started making curvey lines instead of straight and then making the discs look like an eyeball or the CBS logo.

Then at random I picked the next CD: A standard MSDN disc

Nothing strange there, just another uneeded CD.  So I started cutting it to make it unusable.
Here’s what I ended up with:
carved CD

Tip #3: If you let the scenario in Tip #2 go on for two long, cybr starts getting even more creative.

So cutting the bottom of the discs is effective but quite a strain on the blade and edge.  So I wondered what would happen if I sliced the top/label side instead.  Wow! That was even more effective!  Even the slightest slice made the label and reflective surface pull away from the plastic disc making the disc completely unrecoverable.  Then… I noticed that the label could come off.

The slicing kind of got out of hand on the third disc I damaged in this method:
Oops, the label came off

Here’s what a CD looks like without the label and the reflective surface underneath of the label:
I don\'t think this one is going to read anymore

As you can see the reflective material you see when looking at the bottom of a CD is actually part of the label.  But you can still see where the data written to the CD starts and stops on the clear plastic.  The data is actually written in the plastic and is completely see through!  Pretty cool, huh?

The reflective layer of the label only exists to give the laser in the CD drive to bounce it’s light beam off of to be able to read the data in the plastic.  With out the mirror layer, the beam of light would just pass through the data and never be able to be understood by the computer.  So with that in mind…

Tech Tip #4: CDs and DVDs will play with scratches in the bottom surface, but if the top label is damaged, the disc is probably not recoverable.

Hey, that was a real Tech Tip!  I wasn’t really wasting your time after all!