I have copied files to a R/W CD, which was successful. I can't work from the CD to make changes to the file, as the file is now 'Read Only'. The original file copied is not 'Read Only'. Very confusing, help.....

Thanks,

Monashe

Hello Monashee and welcome to http://www.pcguide.com/ubb/pcgubb.gif.
When working from standard CD's, your files are not "changeable" (Read Only) since a standard CD is only capable of recording once. An R/W is capable of being modified, but it is highly recommended to NOT use them in this manner. The risk of data loss is high. To modify and save your files, copy them back to your HDD from the CD, make changes as needed, then save them back to the CD as a backup.

Bassman,

Thanks for the help, appreciate it...

Monashee

CDRWs can be burned in like fashion to CDRs (eg in sessions) in which case the file attribultes are Read Only and can be a real pain. CDRWs can also be formatted for Packet-Writing if you have the right software (Nero's InCD for example). In the latter case they can be used like a big floppy and the file attributes stay as they were originally and don't all become read only.

If you are burning files in sessions and dont want the originals to change their attributes you could include them into a zip file first. Burn the zip file and unzip it when you want to get back the files with their original file attributes.

Hello Monashee.
I routinely and regularly do what you are trying to do with no problems. Not so far anyway, and I've been doing it a long time now on the same CD-RW's.
I do it using "Packet Writing Software" ["DirectCD"] to treat the CD-RW disk like a giant fast floppy or a small slow HDD.
The files are not "Read Only" and can be altered/edited just as they would be on a floppy or HDD. I believe the disk can be written to about 1,000 times, so there is this limit to the number of times this can be done.
If you were to attempt to change the files whilst the CD-RW disk was NOT in a CD-RW drive [a CD-reader for example] they would be "Read Only". Same if you copied them from the CD whilst it was not in a CD-RW drive [to the HDD perhaps].

In fact just yesterday I copied the "Knoppix" OS as an ISO file to a CD-RW disk to make it a bootable CD. So I can boot from this CD and have the Knoppix OS running and type a text file using its text editor and save that text file "to the drive" [which in this case is the CD-RW]. [I should add I'm assuming this can be done, I haven't tried it yet, though I did make a new folder and name it, and that seemed to work ok (or is it being saved to the RAMdrive?)] The CD-RW disk is being used like a HDD. As before, there's a limit to how much this can be done, but I've never yet hit that limit.

Oops!
Just rebooted from the Knoppix CD and that folder I made isn't there.
So I guess it was saved to the RAMdrive and nothing is saved to the CD-RW. :o
Only goes to demonstrate my lack of understanding on that.

I copied the "Knoppix" OS as an ISO file to a CD-RW disk to make it a bootable CD
Suggest it would be less confusing to just say that the iso file was used by the burning software to replicate an original Knoppix CDROM. This could have been done onto CDR or CDRW media - both of which should then have become bootable CDs; the iso file itself wasn't copied or else the CD wouldn't have been bootable and there would have been just one file on the CD; the ****.iso.

I can't work from the CD to make changes to the file, as the file is now 'Read Only'.
Just to recap that the easiest way to make changes to a file on a CD "as you go along" is to use a CDRW with a packet-writing format and to not have a Read Only attribute set on the file(s). All other data formats will change the attribute to Read Only even if the CDRW itself can actually be written-to a number of times.

If you actually reburn the same changed file (same file name and path) to the same CDR (or CDRW) then the new one may appear to have overwritten the older one. In fact what happens is that the reference to the older file is deleted and a new reference is used to point to the new file in a new position. Unlike on magnetic media, such data does not get overwritten - well not until a CDRW is FULLY erased - nor does it get fragmented.

"Suggest it would be less confusing to just say that the iso file was used by the burning software to replicate an original Knoppix CDROM...the iso file itself wasn't copied or else the CD wouldn't have been bootable and there would have been just one file on the CD; the ****.iso."
I said it wrong because I don't really understand what these ISO files are all about. Perhaps you could explain further?

"This could have been done onto CDR or CDRW media - both of which should then have become bootable CDs"
I was trying to give all the facts in as few words as possible, but because my written language skills are not of a high level, I composed it badly. Did it read like only CDRW disks would be bootable? Or did you just want to make it clearer?
I initially thought that by copying it to a CDRW I could treat it just like a small HDD, but obviously that's not so. So the only advantage is that I can reclaim that disk for some other use at some future time.

The term .iso is widely used (in computing vernacular) to indicate an image file of a CD. In that sense they are analagous to .gho files for Ghost or .pqi files for DriveImage for restoring HDD partitions or to .img, .vcd, etc files for restoring the contents of a floppy diskette. The same files can be given a wide range of file extesions with .dat, .bin, etc being other common examples of CD image files.

Perhaps I was being over pernickity but it is common for people to download such files and then directly copy them to a CD. They are then disappointed that their "downloaded CD file" doesn't work as they expected. It doesnt work in like fashion to the way a .gho file would not restore a partition by just copying the file onto the partition. With all such files the correct software must access the file (a) to recreate a floppy (as per floppy images obtainable from bootdisk.com), (b) to recreate a partition (as per a .gho image file) and (c) to create a CD (as per an "iso" file and burning software).

Iso files can represent both bootable and non-bootable CDs and can be burned onto both CDR and CDRW. The latter can of course be reused at a later stage but I think it would be unusual to be able to add any new files to them unless the CD could be first 'reopened'.

The poster's problem (if I understood correctly) was that he couldn't alter an existing file on a CD. The reason being that it had a Read Only attribute. If such a txt file was opened in Notepad directly from the CD and the text changed then the changes would not be capable of being directly saved back to the CD. Since the only way of changing such an attribute on a CDRW is with packet-writing software and an appropriately formatted CDRW, the fact that it was CDRW was of no consequence.

The idea I'm getting from what you're saying is that an iso file like a compressed archive file [are image files compressed archives?]
That the file structure inside it has to be unpacked/uncompressed and only THEN copied to the disk in order to recreate the original or intended file layout.
I know you are very knowledgeable on the topic of "Emergency Boot CD" and "Ultimate Boot CD" and have added utility prog's to customize your copy of EBCD [made on a CDRW as is mine].
Any chance of starting a thread that's basically a class on how to do that?
I would hope a lot of people could benefit from that, perhaps Monashee included.
It could be done as a dialogue, with you explaining what to do and the other person [perhaps me] trying to complete the task and asking questions.

are image files compressed archives?
Image files represent just the raw binary data that has been stored on a medium and couldn't, in general, care less about the file system. Such images can be (virtually) exact replicas (including any bad sectors and so on) in which case there is no compression and the image file will have the same size as the source it was made from; it becomes its very clone. They can also be compressed in a number of ways and using a number of algorithms but the easiest example of compression is to keep a log of every sequence of zero bytes and then include no sequences of zero bytes in the image. When decompressing, that log (usually stuck at the beginning or end of the image file) is then read and the zeros put back into their appropriate places.

I dont think UBCD is customisable though EBCD certainly is. The learning curve isnt too bad once one gets started. It appears you have already downloaded it and made the default (uncustomised) iso and burned it to a CDRW.

So I suggest you start the said thread saying how far you have got and then start off by asking how to add one application (say Ghost or PM) to it. I, or others, can then respond with advice on how to proceed. Its mostly a matter of putting the correct files in the right place and then amending the xml "database" files appropriately. Once you've got the hang of it - away you fly on your own.