File systems

A CD-ROM disk is a read-only file. The entire disk holds about 680 Megabytes which could be broken into several tracks but for most software purposes it would be handled as a single track. A UNIX file system is a file with a special form. Such a file can be ``mounted'' by the UNIX mount command and then it is accessible as a file system (you can snoop around on it using cd and ls commands). The UNIX tar command will take a UNIX directory tree and from it create a single file, but this file will not be in the proper form for a CD-ROM drive. For the material on a CD-ROM to be a file system that can be mounted, the file must be prepared by a tar-like program. One such program that we purchased (with a huge academic discount) is called ``makedisk'' from a company called Young Minds. Before that we mimicked a CD-ROM with the UNIX mount command, by mounting a file system in read-only mode. I believe you can circumvent the purchase of the Young Minds software by having your tar tape formatted (for a price) by the disk manufacturer.