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#1 TMJAVA  Icon User is offline

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CD Burning

Posted 31 October 2012 - 07:43 PM

Hey I need to know if I burn a file to a CD using Live format, can I burn the same file to the same CD again? I'm confused because all the documentation says that Live format treats a CD-R like USB Flas drive. If not, what happens if you attempt to it? Will it hurt a computer? WOuld really like an answer ASAP.

Thanks.
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Replies To: CD Burning

#2 modi123_1  Icon User is online

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Re: CD Burning

Posted 01 November 2012 - 07:09 AM

Quote

Will it hurt a computer?

Why would it hurt the computer? If anything the cd wouldn't be re-writable.


.. but yes, if you have a drive that supports CD-RW and you have a multi-write CDR then you can use it a few times. The gist is it 'blanks out' the existing data and then writes to it again. They don't last as long as a CDR but oh well.

Odd question - why are you needing to use a CD-RW?
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#3 tlhIn`toq  Icon User is online

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Re: CD Burning

Posted 01 November 2012 - 08:01 AM

As modi hints at, the previous session is hidden.
In reality it looks like a flash drive, but it doesn't really work like one because of the simple fact that you have to burn into a CD.

Here's a simple test:
Take 500mb of data.
Burn it to your Live Format disc.
-
Now do it again.
-
Again

How many times can you burn to the disc before it says you can't?
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#4 lordofduct  Icon User is offline

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Re: CD Burning

Posted 01 November 2012 - 08:01 AM

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OP said CD-R though. Not CD-RW.

And Live format can treat CD-R's like rewritable disks... kind of.

The live format is microsoft's rebranding of the UDF specifiction:
http://en.wikipedia....sal_Disc_Format

Specifically they use the VAT mode (virtual allocation table):
http://en.wikipedia....k_Format_builds

Basically in regular ISO-9660 format on a cd-r, the entire disk needs to be mastered, and a toc created for it, which maps out where each block is on the disk. For size constraints the toc just lists the starting block and length of each file. And all data must be written sequentially.

This is an issue for incrementally written disks, because if you add anything to it, the toc needs to be updated, but it can't be rewritten as the disk is write once.

So instead the vat is a toc that can be expanded. Basically everytime you write to the disk a new section of the vat is added at the end of the last write that updates the previous vat writes to the new changes. All of the structures together represent a dynamic toc to find files on the disk. When these disks are read, the computer knows the format, and knows to consider all parts of the VAT in total. (this is why XP and other older OS's don't support it, they don't know to consider all parts of the vat)

When you add a file that exists, or modify a file that exists. The original data is still on the disk... you just end up appending the new version as well. And the VAT now points to the new blocks of data that were written, instead of the earlier blocks.

This means the more times you repeatedly write the same file, the less space you'll have. Though it'll appear as if you only have used 10 megabytes for a large TIFF image... if you've rewritten it 70 times, you can use up the entire disk.

[edit] just like tlhIn`toq points out.

This post has been edited by lordofduct: 01 November 2012 - 08:07 AM

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#5 modi123_1  Icon User is online

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Re: CD Burning

Posted 01 November 2012 - 08:04 AM

Thanks guys for the extension. Still rubbing Halloween out of my dried out eyeballs.
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#6 TMJAVA  Icon User is offline

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Re: CD Burning

Posted 02 November 2012 - 10:48 AM

View Postlordofduct, on 01 November 2012 - 08:01 AM, said:

OP said CD-R though. Not CD-RW.

And Live format can treat CD-R's like rewritable disks... kind of.

The live format is microsoft's rebranding of the UDF specifiction:
http://en.wikipedia....sal_Disc_Format

Specifically they use the VAT mode (virtual allocation table):
http://en.wikipedia....k_Format_builds

Basically in regular ISO-9660 format on a cd-r, the entire disk needs to be mastered, and a toc created for it, which maps out where each block is on the disk. For size constraints the toc just lists the starting block and length of each file. And all data must be written sequentially.

This is an issue for incrementally written disks, because if you add anything to it, the toc needs to be updated, but it can't be rewritten as the disk is write once.

So instead the vat is a toc that can be expanded. Basically everytime you write to the disk a new section of the vat is added at the end of the last write that updates the previous vat writes to the new changes. All of the structures together represent a dynamic toc to find files on the disk. When these disks are read, the computer knows the format, and knows to consider all parts of the VAT in total. (this is why XP and other older OS's don't support it, they don't know to consider all parts of the vat)

When you add a file that exists, or modify a file that exists. The original data is still on the disk... you just end up appending the new version as well. And the VAT now points to the new blocks of data that were written, instead of the earlier blocks.

This means the more times you repeatedly write the same file, the less space you'll have. Though it'll appear as if you only have used 10 megabytes for a large TIFF image... if you've rewritten it 70 times, you can use up the entire disk.

[edit] just like tlhIn`toq points out.


Thank you lordofduct for your complete and thorough answer. Now I know I can write the same file to a CD-R as long as it's in Live Format. Of course, at some point, it can get full, but if it's a 1kb file, that's being written over, that may take a while. Thanks.
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