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marylyn27

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Help re: CD-R versus CD-RW ????

hi...i have an iomega 12x10x32 cd-rw. what confuses me is...i thought CD-R disks could not be written-to after used once. but i found that, at least with this one fild i keep modifying, i can save it over and over again on the same CD-R disk. why is this? how is it that i can continue to write to the cd-r? will this last indefinitely?

i'm confused!

thank you,

marylyn :))
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Jenn050402

marylyn27,
You can continue to write to CD-R's as long as the disk isn't filled up. Once the disk is filled you will no longer be able to save to it.
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Jenn050402

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In what is called 'multisession' mode, a CD-R can be added to.  So what it's doing is not rewriting your file but saving the complete new version and marking the previous version as invalid.  It will do this until you run out of space.  For example, a 100MB file can do this trick 6 times before the CD is full, even if you only change 1K of the file at a time.

Of course, you may have put in a CD-RW disk by mistake.  The sample disk(s) that came with the unit certainly unclude at least one CD-RW type, which can be rewritten.
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thank you all very very much! this explains it. yes, it does overwrite the previous file version. i see what's happening. so, once a track (or whatever you call it) is used on a cd-r, that's it. but a cd-rw "track" can be used over and over.

that's really pretty good, if you think about it. my file is about 1 mb. so, technically, i could save it about 650 (more or less) times on a cd-r. i was told that even using a cd-rw disk it might only be usable 1000 times, when it would have to be discarded. so, it makes cd-r disks that much more advantageous...

marylyn
glad to help
Even though this question has already been answered and closed, I can't let this go by:

"using a cd-rw disk it might only be usable 1000 times"

While technically correct, you've misinterpreted this specification.  The CDRW drive keeps track of where each CDRW disk has been used.  Each time you 'rewrite' a file it doesn't go on the same physical location on the disk.  Only after using the entire disk at least once will a given spot be overwritten.  

Thus, if you have a single 650MB file that is completely changed and rewritten then the disk will wear out after 1000 uses.  But if you have a 1MB file, it can be changed and rewritten 1MB * 650MB * 1000 = 650,000 times, making CDRW disks MUCH better than plain CDR disks.
i understand...so, technically, the advantage still stands. thank you for that very helpful clarification...

i'm deeply impressed with breadth and depth of knowledge here. but you express yourselves so concisely and clearly, as well. i model clothing as a career, and am not home much. i've taken upon myself to learn about my home pc...a sort of hobby. you guys are helping me along.

again, thank you!

marylyn :))