Macintosh CD-ROMs

Summary: Information on Macintosh CD-ROMs. How to read Macintosh CD-ROMs on a PC. How to produce Macintosh CD-ROMs on a PC. Links to all other pages of this site about CD-ROMs.


As a consequence of the explosion of the CD-ROM burning tools (hardware and software), CD-ROMs are now ubiquitous and are used heavily to transfer data files amongst computers. However, Macintosh CD-ROMs keep some mystery (in particular for PC users) and aren't always well understood. Why are Macintosh CD-ROMs different? Is it possible to read them on a PC? Can Macintosh computers read classical CD-ROMs (conforming to the ISO 9660 standard)? Is it possible to produce on a PC a real Macintosh CD-ROM? With which tools?
This page presents answers to these questions and contains links to all relevant pages of this site. See also the part of our site map on CD-ROMs.

What is a Macintosh CD-ROM?

A Macintosh CD-ROM, as all other Macintosh storage media, is organized according to the HFS standard. The acronym HFS means Hierarchical File System. This is the name of the Macintosh file system, introduced after the first "flat" one, used on the 400 KB floppy disks.
Contrary to the PC, where CD-ROMs (ISO 9660 CD-ROMs, to be more precise) follow a specific storage scheme and aren't formatted like MS-DOS or NTFS media, Macintosh CD-ROMs are like other magnetic disks and are in fact often images of real (physical) magnetic disks.

Can a Macintosh CD-ROM be Read on a PC?

No. Better said, not without some special software, like our MacDisk.
It can happen that you get a CD-ROM from a partner without knowing whether it is an ISO 9660 CD-ROM or something else. How to ascertain the very nature of the disk?
Under Windows 95 and NT 4, when you try to open a HFS CD-ROM in the Explorer, you get the message:

A device connected to the system doesn't work correctly.

(This is a translation back to English of the French message, but you should get it right).
Under Windows 98 and higher, the behavior of the operating system may lead to misunderstandings, because it displays an empty window and even gives it a fake title of 'CD'.
It can also happen that the Macintosh user burnt a CD-ROM as an ISO partition with Apple and/or Joliet extensions. In this case, you can get crippled filenames without real extensions and have no clue about the real contents of the files. See our page on such ISO volumes produced on a Macintosh.
In all those situations, your best bet is to try our MacDisk, which can manage all kinds of disks produced on the Macintosh.

Can Macintosh Computers Read ISO 9660 CD-ROMs?

Yes. Again, better said, under some conditions and with some restrictions.
The Apple Macintosh computers can read two kinds of CD-ROMs: first, HFS CD-ROMs (see above). Then (if the correct extensions are loaded), ISO 9660 CD-ROMs. Depending on the version of the operating system, the Macintosh accesses the Joliet long filenames or not (there is an extension written by Thomas Tempelman to alleviate those problems). Again, depending on the settings of the computer, the very nature of the data files will be recognized or not (the Macintosh file system doesn't use extensions to characterize the files, but signatures). Therefore, the user may be able or unable to open a file by double-clicking on the file icon.
Last but not the least, Macintosh programs are generally stored in the resource fork (see our page on forks for more information on this aspect). Since no one of the major CD-ROM burning software packages on the PC manages Apple extensions to ISO 9660, it it not possible to install a Macintosh program on an ISO 9660 CD-ROM.
MacImage (version 7) now features such a mode.

Three Reasons to Burn Real Macintosh CD-ROMs on a PC

Those three reasons (accessing long filenames, identification of the file contents, installation of Macintosh programs) are enough to justify the effort of producing Macintosh CD-ROMs on a PC. This is even more true if you are a professional and want to distribute your CD-ROMs to potential customers without knowing their computer equipment, their computer knowledge and the like.
We present on this site a range of solutions to produce Macintosh CD-ROMs on a PC.

Other CD-ROM Pages

We publish on this Web site numerous other pages on CD-ROMs. The list below can be used as a little sitemap of all those pages. Some of them are rather general, while other ones pinpoint some often ignored questions:

Pierre Duhem (ex-Logiciels & Services Duhem)
3, rue Pierre Haret - F-75009 Paris (France) - Tel. (+33) [0]149 700 455