I received an email from a reader recently that asked about writing CDs, so let's work on that this week. The problem is that CD writing evolved over time, and depending on when you bought your CD drive and what software you have, techniques differ.
The original CDs were read only - they were manufactured and could only be read, not written. The purpose was mainly for the distribution of programs and data. The manufacturing process is quite complex, but involves creation of a master which is then copied by a polycarbonate injection process followed by metallization. Whew! Anyhow, it works. But you couldn't write CDs on your PC yet.
Writable CDs (CD-R) emerged a few years later. The technology is actually quite different from the original CD and uses a dye layer burned by a laser to store the data. But when writing, the laser has to stay on for all the time you write - thus the data must be prepared by the PC prior to writing so as to have it all ready when needed. The term for this single write was called a "session".
At first, you could only write a single session, but multi-session drives came out later, introducing another problem. Even though there are multiple sessions, the whole disk itself still looks like a single unit - thus if you wrote file x.doc in the first session and again in the second session, a way was needed to logically delete the first one. This worked but caused a lot of software overhead, as for each file it had to look at all the sessions. More than two or three sessions caused significant slowdowns.
CDs at this point were called WORMs - Write Once, Read Multiple - meaning that you could write them only once. Later re-writeable CDs came out (CD-RW) but these only allowed you to erase the entire thing and re-use it again.
There are a number of software packages used to write CDs, but they all work basically in the same way. You start up the software, pick a list of files and folders to be written, and when done with the list click Write or Burn and the CD is written.
Windows eventually added its own support that does not require any special software program. You just write or copy to the appropriate drive (D: or whatever your CD writer drive letter is) and Windows would keep those files until you are ready - you then click "Write Files to CD" and Windows would actually write them. If you think about it, it is basically the same thing - creating a list of files and then burning - just done in a different way.
But in any case, CDs could not be used as replacements for floppy disks - you could not just write an individual file or part of a file when you waned to. As such, CDs were only for backup or to move data from one place to another.
But using a CD as a floppy is what the public seemed to want, so the industry came up with some ways to do that. In general, it is called "packet writing" and can only be done on CD-RW disks. At first the CD software vendors supplied their own software to do this - sometimes called InCD or DirectCD. The clue that you might be using one of these is that you are required to format the disk first - a very long process. But the results were less than spectacular - the process of writing data in this manner was very slow, and the disks were often not compatible between systems. The clue as to whether you are using packet writing or not is if you are asked to format the CD - if so, you are packet writing.
There was an effort called "Mt. Rainier" to replace packet writing software using specially equipped CD writers that allowed the formatting process to be "under the covers" and for overall performance to be better, but I think Mt. Rainier sputtered out somewhere along the line. A search for "Rainier" on the Microsoft website did not yield any significant results. For DVDs, something else called DVD-RAM seems to have replaced Mt. Rainier, but this is not available for CDs.
So, the bottom line is that I don't recommend packet writing. Your data should be on your C: drive, and use a CD (or DVD) only for data backup or transfer. I do not recommend using CD-RW as the technology is less reliable and CD-Rs are so cheap as to be throwaways. Write them using the software that came with the drive or PC or use the Windows built-in support, and when you are done with it either throw it away or put it on the shelf.
(Bob Seidel is a local computer consultant in the Southport - Oak Island area. You can visit his Website at www.bobseidel.com or e-mail questions or column ideas to him at bsc@bobseidel.com. For specific inquiries, please call Bob Seidel Consulting, LLC at 278-1007.)