Well maybe there are things that the teacher wants to use in a fast swap way like old flopies only bigger (Zip 100-200MB; CD-RW - 650MB)
Nero has a tool called InCD that makes your CD-RW work like a floppy, maning that you just drag in and out of the CD-ROM and it automaticly writes, copies, and erase the data. But this process cut's the CD-RW's life time considerably allowing you around 20-30 uses.
If it is used as a regula CD-R, you can burn all the information you need, and when it's full and you can change everything on it, you could just erase data, and you have another clean CD-R(W)
I think this way you have over 100 uses (depends on the quality of the CD-RW)
Re: CD-RWs
Threaded Mode
