March 2002
This month I think we will share a little information about the CD-R and CD-RW, with a little humor added.
What's CD-R? CD-RW?

CD-R is short for "CD-Recordable". Recordable CDs are WORM (Write Once, Read Multiple) media that work just like standard CDs. The advantage of CD-R over other types of optical media is that you can use the discs with a standard CD player. The disadvantage is that you can't reuse a disc.

A related technology called CD-Rewritable (CD-RW) allows you to erase discs and reuse them, but the CD-RW media doesn't work in all players. CD-Rewritable drives are able to write both CD-R and CD-RW discs.
All CD recorders can read CDs and CD-ROMs, just like a standard CD-ROM drive.
Can I just copy files onto a CD-R like I would to a floppy?

Yes and no. The process can be a bit more involved than that, and requires special software that (usually) comes bundled with the drive.
With "packet writing" software, and a recorder that supports it, you can treat a CD-R or CD-RW disc like a floppy. Generally speaking, you can only write to each part of the disc once, so deleting files doesn't gain any space. There are other limitations as well.
With more traditional software -- necessary if you want the broadest possible compatibility -- you usually end up writing everything to the disc all at once. When you're doing the writing you can't interrupt the drive, and you can't reclaim the space you've used. If you want to write your files in smaller bunches, you lose a fair bit of space every time you stop and start again.
What can I do with CD-R discs that failed during writing?

If the disc wasn't closed, you can write more data in a new session. If the disc was closed, or was nearly full when the write failed but is still missing important data, then its use as digital media is over.
However, that doesn't mean it's useless. Here are a few ideas:
· Fill in the center hole to avoid leaks, and use them as drink coasters.

· Create a hanging ornament (suitable for holiday decorations) or wind chime. The latter isn't all that interesting - they just sort of "clack" a little - unless you use the discs to catch the wind and something else to make the chimes.

· Use them as mini-frisbees in an office with cubes. Since they're rather solid and may hurt when they hit, you should await a formal declaration of intra-office war before opening up with these.

· Have CD bowling tournaments where you see how far you can roll one down a narrow hallway. You'd be surprised at how hard it can be unless you get the wrist motion just right.

· Put them under a table or chair whose legs don't quite sit right.

· Run them through one of those industrial-strength paper shredders (the kind with the rapidly spinning wheels) to get shiny green or gold confetti.

· Make really, really big earrings.

· Try to convince people at the beach that it's a shell from a new species of abalone.

· Hook them into your bicycle spokes as reflectors.

· Use them as wheels on a toy car. (If you had buggy firmware, you're probably stocked for a toy 18-wheeler.)

· Build a suit of "CD-R chain mail" for laser-tag games.

· Use them as art-deco floor or ceiling tiles.

· Hang them from the rear view mirror in your car.

· Cut it into a jigsaw puzzle with a small wire saw.

· Try out the "helpful CD repair" suggestions that periodically crop on the newsgroup. Like the ones that suggest using acetone and sandpaper to refinish a scratched CD-R.
· Hang them in your car windows. Some people believe that CDs will defeat speed guns and automated speed traps that use flash photography.

· Add them to your aquarium.

· Use them as dart boards or BB-gun targets. If you "miss" the hole in the middle, the error is immediately obvious.

· String several together as a toy. Alternate green and gold for visually pleasing results.

· Make a boomerang (<http://www.chez.com/amiel/boom/cd.html>).

· Buy a cheap clock mechanism from a hobby/electronics store, and turn it into a novelty clock.

· Hang them in fruit trees to scare birds away.

· Use them as backing for round knobs on cabinet doors, to keep the wood from getting soiled. Works best with 80mm discs.

· Practice applying CD labels. Test brands of labels you haven't tried before. Leave them in the sun and see if they peel.

· Gripping the CD with two pairs of pliers, hold it over a small heat source, such as a small propane torch. Keep it moving slightly so it doesn't scorch. When the plastic reaches the melting point, stretch, twist, or bend the CD into something artistic. (Do this in a well ventilated outdoor area with adult supervision!!)
If you've given up hope of doing something "useful" with it, do something destructive with it. Try to scrape the reflective layer off the top with your fingernail. Drop it on the ground so that it hits edge-on and see if the reflective layer delaminates or the plastic chips. Try to snap it in half. Leave it sitting on a window sill with half the disc covered by a book to see the effects of heat and sunlight. Write on it with nasty permanent markers and see if you can still read it a week later. Apply a CD label then pull it off again. Different brands of media have different levels of tolerance to abuse, and it's useful to understand just how much or how little it takes to destroy a disc.
In one carefully controlled experiment it was determined that CD-Rs behave differently from pressed CDs when you slam them edge-on against the ground. The aluminum ones will chip (once you throw them hard enough, otherwise they just bounce) and create silver confetti. The gold one I tried chipped and the gold layer started peeling, leaving little gold flakes everywhere. One user reported that a Verbatim blue CD developed bubbles even though the plastic was intact. More experimentation is needed (but not around pets, small children, or hard-to-vacuum carpets).
On a different tack, some CD-Rs don't hold up well when immersed in water. Try pouring a little water on a disc, then let it sit until it dries. If the top surface scratches off more easily afterward, you need to be careful around moisture. Silver/blue Verbatim discs seem particularly sensitive.
One comment about snapping discs in half with your fingers: use caution. Depending on the disc and how you break it, you may end up with lots of sharp polycarbonate slivers flying through the air. Wear eye protection, be aware of people around you, and be sure to clean up all the plastic shards afterward.
CD-R's and CD-RW's
Why was the Easter Bunny so upset?
He was having a bad hare day!

Would you like something from my Easter basket?
"Sure!"
"Here. Have some plastic grass."

Why do we paint Easter eggs?
Because it's easier than trying to wallpaper them!
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