CompuServe Messages

I guess I need to clarify another point. You can read ISO-9660 disks on a UNIX book and you can access the data as you would a normal file but you can't run DOS programs. My Atari ST and the IBM have the same type of filesystem ("MS DOS LIKE"). I can move files back in forth between my Atari and the IBM PC. I can read/write ascii, database, and other data files without any problem. But I can't run DOS programs on my Atari. My Atari uses a 68000 like an Apple MAC does and IBM uses the intel cpu 80286. And the IBM can't run my Atari programs but they can share data because they understand the same filesystem. UNIX, Apple, Atari, IBM, etc can all understand ISO-9660 CD-ROMs, all platforms can read the same data files. But you can only run IBM programs on the IBM, Apple programs on an Apple, Atari programs on an Atari and UNIX programs on a UNIX machine. Propietary CD-ROMS can be very easy to do you can dump an Apple hard disk to a CD-ROM so it is effectively an Apple hard disk. This can't be read on other platforms very easily. You can have a file on the disk the the program checks for and then makes a comparision with the hardware. Then if this machine is not the same then it doesn't run the program. You can do several things to make them proprietary very easily. The Sky is the limit on that one. UNIX systems now support the Rock Ridge format for CDROMs. What Rock Ridge is … is an extension on top of ISO-9660. So you can still read a Rock Ridge CD-ROM on any machine that can read ISO-9660. But only with a Rock Ridge driver does one get all the benefits on UNIX on an ISO-9660 compliant CD-ROM. This a perfect example of why ISO-9660 is such a great standard. If you can put extensions on top of the standard and still have access to the original standard (ISO-9660) you have designed a very good extension to the standard.