OK.  I've tried even more cdrom hacking.  Here's what I've found, or
at least guessed at.

Normal ISO images do not work for booting.  I've tried several
variations of the mkisofs command, many NetBSD, OpenBSD, FreeBSD and
windows cdroms.  The only ones that work are the WinNT ones that
appear to have a FAT file system on them as well as the iso9660 one.
I say appear to because I've looked specifically at the "special"
cdroms to see why they work and others don't[*].  So I'll look into
this a little more and let people know what I find.

I'll try to burn an MSDOS FAT cdrom tomorrow at work to test this
theory out.  Maybe I'll just bring home the cdburner to make testing
easier :-).

I notice that there's support in mkisofs for hfs (mac) co-formatting
of the image.  However, I've not looked at that code.

Warner

[*] The reason I haven't is lame: I'm ripping my music cd collection
into MP3s and don't have a space cdrom to check with. :-)