I know.....I know....this has nothing to do with poser but i didnt have anytime to go to another forum so i just came here......heres the question how can i convert a nonrewritable cd into a rewritable? (if its possible!)

Not possible sorry. They use entirely different media. You can however copy from your CD-R (recordable) to a CD-RW (rewritable).

ok...ok...

And I recommend you tranfer from the CDRW to the CDR. The rewritables are notorious for data loss.

maybe I'm not understanding the question.. I've heard it said before, that you can not write to a cd-r more than once. but I do all the time, I never use cdrw's, I only use cdr's. I just leave the disk open, I can't read from the disk from any other drive till I close the disk, but as long as I leave it open, I can delete from the cdr and write more to it at a later time. I never understood, why I am able to do this, yet everyone says it's not possible. if I misunderstood the question, just ignore me :o)

CD-R disks: ********************************************
The data area on the disk can only be written once.
Once this physical area on the disk is used, it can not be used again.

When a file is "deleted" from a CDROM, the data area is just marked as unusable, and as more files are added, eventually all the physical "data space" on the disk is used up and no more data can be written to that disk.

The CD-R disk can be programmed to:

1. allow access in only CD-RW drives (this can be changed)
2. allow access in any CDROM drive (this can be changed)
3. prevent any additional data from being written to the disk (READ ONLY!)
   ... (this can only be done one time - obviously!)

CD-RW disks: ********************************************
The data area on the disk can be written many times.
The physical area on the disk is used over and over just like a hard disk drive.

I do not know the "life" of a CD-RW but I am sure it has a finite "life."

The cost of CDROMs (purchased in bulk, i.e., 50 or more) is about the same as a 1.44 MB floppy disk. (e.g., about $.30 each)

A CDROM holds, typically, 700 MB or the same as 486 floppy disks.

I usually keep 50-100 CD-R disks in my supply cabinet and I use them as freely as I would 1.44 MB floppies. When a CD-R disk goes bad, I simply throw it away.

I backup all my expensive software on two CDROMs because it costs very little to do that.

I hope this info helps.

cheers,
dr geep
;=]

Mystic, when you delete data from the CDR it is not taken off just made unuseable and that space is not recovered to use again...thus, the meaning of "can only be written to once."

I understand that. :o) some people say they write to a cdr just once, that's it, they can't keep writing to it (example backing up all the poser things at once because one you burn you can't add more) but I've always been able to add more later to the same cdr. I just keep adding till it's full.. so many people don't know that, they assume, write once that's it, no more adding to the disk.

The concept is no different from creating what we call "sessions" on a Mac (I don't know, there may be the same term for PCs), where you keep adding to the CD until it's full. But a CDRW cannot be erased, at least not according to the documentation that came with the CDRW writer on the PC -- all you can do is add to the disk until it's full. And as I noted above, the data loss rate for these things is notorious: it appears it's just not a fully developed technology yet.

You can write to a CD-R as many times as you want -until- the disk is full! A CD-R is like a blank piece of paper. You can write one line and you still have lots of space. Now you can write more lines on the piece of paper anytime you want. -but- You can't "erase" what you wrote on the paper. Deleting lines from the paper does not "erase" the line(s). It just "crosses them out" so they can not be read. You can keep writing lines on the paper until the paper is full. Then, you need to get another blank piece of paper. (i.e., another blank CD-R) A CD-RW works the same way ... -except- that when you "delete" a file from a CD-RW, it is like erasing the line from the piece of paper so that you can use that physical space over and over again. cheers, dr geep ;=]

You said ...
"But a CDRW cannot be erased, "

A CD-R can not be erased. (per se)

A CD-RW can be erased which is why it is call read/write.

The technology that is used does this:

A laser beam of light is used to microscopically modify the surface of the disk.

A CD-RW only "scratches" the surface slightly so that the "scratches" (i.e., the data written) can be removed. That is, the "writing process" is reversed.
Now, that exact same area on the disk can be "scratched" (i.e., written to) again.

A CD-R, on the other hand, has the "scratches" (written data) made deep and hard and permanent.

That is why CD-Rs are more reliable than CD-RWs.
The data is "burned" into the disk much deeper and more permanent.

cheers,
dr geep
;=]

You must be using a different burn technology than the one we have here on the Compaq. Ours can't be erased, just added to.

Ok, but ...

Then, what IS the difference
between
a CD-R
and
a CD-RW?

Now you've got me curious.

cheers,
dr geep
;=]

On our machine, a CDR can only be written to once -- the burning software doesn't allow you to keep a data disk open. It's possible that I have an older or limited version of this stuff, since I don't normally burn my CDs on the PC.

everyone I know, says the same thing VirtualSite. so maybe it is a difference in the software used to burn the cd's. until geep confirmed it was possible.. I wondered if it was just me.

Attached Link: http://www.pctechguide.com/09cdr-rw.htm

Cool. Thanks. I don't know that I would trust CDRWs any more than I do now, but it's nice to know I could add to a CDR if needed to.

Epilogue:

The CD-R actually burns the data into the "Recording layer" surface of the disk. This makes it permanent.

The CD-RW has an electrostatic charge placed on the disk between the "Dielectric layers." That's why it can be erased - by neutralizing or "erasing" the "charge."

It's just like static electricity. Over a period of time (maybe a long time), this static charge can "leak-off" and the "data" is lost.

That is why CD-R disks are more reliable than CD-RW disks.

cheers,
dr geep
;=]

VS You've probably looked everywhere already, but in Nero the option to erase a CD-RW is under the CD-Recorder menu and the toggle for locking a CD-R is a check-box in the write dialogue just above the speed selection - Finalise (prevents further writing)

I gave up on using CR_RW shortly after getting the unit. The problem was not the failed burns, it was the unpredictable nature of losses after the burn -- just sitting in the case. After 6 months, I would guess that I had a 30% failure rate on discs that initially read OK after the last burn. Can't have that! Kinda defeats the purpose of a backup. At least with CD-R's, although I still often get "coasters" out of the oven, once it's on there, the data seems to stay put. Admittedly, this was early CD-RW software & media (4 yr old?). Has it gotten significantly better? -- or cheaper?? How much are CD-RW discs now?

It's just like static electricity. Over a period of time (maybe a long time), this static charge can "leak-off" and the "data" is lost.

"After 6 months, I would guess that I had a 30% failure rate on discs that initially read OK after the last burn. Can't have that! Kinda defeats the purpose of a backup."

Now we know ............. sort of.

Thanks for the input Nance.

cheers,
dr geep <--------------------[getting ready to trade in those CD-RWs]
;=]

I wonder if these new rewritable DVDs have the same problems as CD-RW.

Um, ......... they probably do LD. I don't believe they have improved the technology yet. That's just my opinion, I could be wrong. ;=] Anyone out there in R'os'land got any info on this?

I'll never use CD-Rw's again. My slave HD had a crash 2 months ago. Because I had everything backed up on 11 RW Cd's, I wasn't really worried. When I was ready to re-install my files, Surprise! 6 RW cd's of those eleven were corrupted. All I got from them were blue screens, crashes and a big, enormous data loss.

O U C H ! ! !

no cheers, <--------- (for that one)
dr geep
;=[

DOOH! I thought they were strictly optical media. However, from the info above about "dielectric layers", would that indicate that CD-RWs are subject to influence from magnetic fields, similar to tape and magnetic discs? And if so, do they require the same storage precautions as other magnetic media? That could certainly explain my data losses. (discs sitting on monitor & speakers)

That is a definate possibility. ;=] [unfortunately] It appears to be best to only use CD-R type disks. They are certainly ceap enough, no? ;=]