Worked really hard to screw up a perfect CD-R yesterday afternoon...
I think it was since Vista when windows start to allow users to "use CDs and DVDs like an USB drive."
In other words, you could delete and rewrite files to the same medium again and again...
Yet, if I recall correctly, I have been rewriting files to CD-Rs for years as long as I don't finalize the session... 8-O
The only difference I see is the addition of the delete function...
So, since, in theory, based on my understanding of
how CD-R works, once a file is written on a specific region on the CD, there ain't no nothing else you could do about that area any more. The reason why you can continue to write files to the same CD is because certain areas have not been touched yet.
So, how could the live file system format claim to allow you to delete and erase files on write-able (not rewrite-able) media?
I played around by first adding files to the CD and later delete a file or two from it.
Voila! It did work...
After a file is deleted from the CD, when you pop the CD into the drive again, the file did disappear as if it really got erased.
So I added more files and deleted more files.
And, of course, it still works...
The next step I took to resolve this mystery of mine was to check the amount of disk space on this CD that has been used numerous times so far.
You see, a CD-R could hold up to 700 mb. Since the two files I had on the CD-R totaled up to something about 24 mb, there should still be at least something over 600 mb available space on the disc. However, it was shown that there was only a bit shy of 500 mb available.
So, I tried to write a file that was about 490 mb onto the CD.
At a certain point, the process stalled and the the process-bar stopped moving.
I clicked on cancel to cancel the CD writing process. Yet, even the canceling process seemed to have stalled... I tried to close the window by clicking on the red x.... still nothing happening...
Somewhere around my attempts to stop the CD-writing process, I checked the size of the CD and found there to be only 207 bits of free space available.
Towards the end, I had to go to the control panel to manually kill the process... Afterwards, for a while, you don't see the ordinary windows interface anymore.... because... possibly... windows' explorer not responding...
And... I finally sort of crashed Windows 7... 8-O lol
Back to that CD, I guess, because I did not give the computer a chance to properly end the process, no longer could I view the CD using Windows 7 and I tried it using 2 machines with windows 7 on it... one PC and one Mac running parallel...
In addition, I tried to see whether Macs could read the CD... because, used to be, Macs were so much better in reading media and files even if they were really badly corrupted... When PCs fail to read a disk or a file, sometimes you simply have to take it to the Mac...
Unfortunately, all four Macs I tested on did not even recognize the media and whenever I put the CD in, the machine makes really scary noises.... for these three, one runs snow leopard and the other three running simply leopard...
The only thing that could read this CD so far are machines running windows XP as well as Windows XP mode on Windows 7.... Although it takes a long time for the CD to finally load, I have been able to see the last two good files seen on my Windows 7...
To sum up....
- I finally crashed Windows 7
- Windows XP could read a bad CD many other OS, PC or Mac, could not read.. will still have to try it on Linux
- In addition, when using CD-R as USB drive, I don't think it really rewrites the files. Rather, it mights have simply been marked in a way that the "deleted" files become hidden... so hidden that you still won't see them even you unhide all hidden info. Just a guess....
