Friday, December 10, 2010
About data CDs and DVDs
It's the Christmas shopping/baking/traveling season. This week only one person showed up for the Thursday night tech talk, so it turned into a highly personalized one-on-one session. The patron had an interesting question, one I've only heard one other time. He wanted to learn how to write files to a CD, and he wanted the files to be written in a predetermined order. In particular, he talked about the requirement for chapters in a book in progress to be written to the CD such that, when it was opened, the recipient would see the files in the proper order, one chapter per file.
I had this question several months ago, in the context of files being prepared to send to an attorney, and the files had to be "written in order."
I didn't spend a lot of time questioning the patrons to find out how they arrived at this requirement. It may be that the attorney who was to receive the CD had communicated the requirement. It may have been the budding author who wanted to ensure that his first chapters were read in the right order. Most people have had quite a lot of experience with audio CDs, but may have little or none with data CDs, so it's understandable that they might think that the order of files on a data CD matters. But in fact, the contents of a data CD are going to be viewed by the recipient using Windows Explorer, and that's going to determine the recipient's view of the CD. The directory of the CD can be viewed in alphabetical order by the name of the file, in order of the size of the file, in order of the type of file, and in order of date last saved. Each of these can sorted in ascending or descending order. The view can be customized somewhat, in that columns can be added or subtracted, but there is no view that would allow the average Windows user to see the files in the order that they were written to the CD. (Open "My Documents" and select "View" > "Choose details..." from the menu bar to see all the fields that can be added.)
There are many formats of CDs and DVDs, and depending on how you are going to use the resulting disc, you may choose a different type of media. This table spells out the differences between various kinds of CDs and DVDs and how to use them when writing data files.
The patron who was preparing documents to send to an attorney was satisfied with my explanation that Windows Explorer controls the view of the directory of the CD's contents. I didn't get any feedback, so I assume the attorney was satisfied, too. The author was happy when I showed him how he could create folders on the CD, with names like "Chapter 1," "Chapter 2," and "Chapter 3." He was not as happy about my first suggestion, which was to prefix each file name with a chapter number. In Word, a new section can be defined for each chapter, so it's not really necessary to split up a book into separate files, unless it's more comfortable for the writer to work that way. But section headings, page numbering, tables of contents, and indexes are pretty advanced topics for someone who is just getting started with files and folders, so I didn't even mention them.
(flickr image by sun dazed)