OK.  FAT was a wild goose chase.  At least I didn't burn a cdrom with
it :-)

I dug up my copy of the ARC BIOS specification (version 1.00) and it
just says that it uses iso-9660.  Well, it talks about a root
directory named SYSTEMPARTITION, but it also talks about a directory
in the root partition named SYSTEMPARTITION.  So I'm confused.  Time
to crank up some code and read the simple iso9660 header blocks and
such and see why some cdroms that I have work and the ones that I
create do not.

Warner