The latest on premastering, plus essential and optional CD-R features
Last month I discussed the latest developments in CD-recordable hardware. Of course hardware is worth nothing if there is no appropriate software to make it work. The difference that your choice of CD-recordable software makes may not always be obvious, but what PC Magazine found in comparing CD-R drives of the same league tested by different software (April 9, 1996) says a lot. The most telling fact was that on the very same CD recorder, the Yamaha CDR-100, it took 15 minutes for Incat's Easy CD Pro to create over 18,000 small files totaling 280 megabytes, while the same task took 30 minutes using Corel's CD Creator.
Of course, we have to put these things in perspective, and that means not complaining too loudly about 30 versus 15 minutes. Just think about these issues: How long would it have taken to copy 280 megabytes worth of files to floppies? To streaming tape? How many floppies would have been needed? How much would it have cost to ship the floppies or tape somewhere? How much time would have been needed to make the absolutely essential directory of the 18,000 files? In the case of streaming tape, how long would it have taken to find a single file at the end of the tape and load it into memory? Given the answers to these questions, I think none of you would complain but would rather leap at the CD-ROM alternative with whatever software works.
Nevertheless, if there are options in choosing premastering software, it pays to know the pros and cons of the different programs and to choose the best for your needs.
The name premastering software itself is somewhat misleading. Originally, we needed such software to prepare a file that was used to create the glass master that in turn was used to stamp hundreds or thousands of the "end product"-the familiar silver-coated CDs. But often in the inhouse CD-ROM publishing process, there is no need for mastering and stamping. You yourself create all the originals (on gold-coated disks).
If you use the CD-R drive to prepare archives for your files, you need only one or two copies. If you just want to make a prototype of a database for internal evaluation, a few copies may suffice. Even if you want to distribute three dozen copies of your policy manual or annual report, it makes more sense to create them in-house instead of farming out the job of mastering. If you need more copies you still may use your in-house CD as a premaster, and then the qualifier "premastering" would be completely logical. Let's stick with this word even if, formally, it may not be perfect.
In the premastering process, some functions are essential and common across all products. (Additional, optional ones I'll discuss below.) First, the user identifies those files to be put on a CDROM and the premastering software verifies that the files and directories comply with certain limitations put forth in the standard known as ISO 9600. For example, the file names must not include characters other than 0-9 and A-Z, and they may not be more than eight levels deep from the root directory level. You would not believe how often these specs are violated, especially the use of special characters such as the - symbol or the + sign in file names.
The premastering software then adds error control and detection characters to the files. It may also create a copy of the physical ISO-9660 image of the original files or just a virtual image of them that merely lists their location and warns you if one or more of the files were not found. (The first version of CD Creator was criticized for not offering the option to create a real image, but the current version has this feature.) It should be noted that in the virtual-image-building process, the time it takes depends on the number of files and not on their size, as no actual copying occurs.
Beyond the number of files, the extent to which they are "scattered" across the hard disk is also a factor. …