Reading 80 minute CD-R's in modern Macs

We just got a new Mercury Pro CD/DVD/BlueRay drive (with ASMedia ASM1053E chip set) from OWC. The first CD we put in was a Maxell 80 minute (actually listed as 79 minute) CD-R with just .jpg files on it. The Mac Air M2/Ventura said it could not read it. Using disk utility to mount it says “Could not mount “disk4s1sa”. ( entry error - 119930868.)” (see attached). This CD-R disk reads just fine in a G5 Pro desktop/Leopard, and a 2011 MBP/High Sierra. This Mercury Pro/Mac Air M2 combination reads other CDs and CD-Rs just fine. OWC tech help suggested plugging the Mercury drive into the 2011 MBP to see if the drive read the CD-R on that machine. It read it just fine there. A 2015 MBP/Monterey using this Mercury Pro CD/DVD/BlueRay drive also could not read this disk, same error. So the problem is obviously the Mac Air M2/Ventura and the MBP/Montrery do not like 80 minute CD-Rs. The two images below are when just inserting the CD-R into the drive, and the second when trying to mount the CD-R in Disk Utiltity.

Screen Shot 2023-04-07 at 4.51.28 PM

From the screenshot, they are “Mac OS Standard” volumes, which is another name for HFS. Apple dropped support for HFS in Catalina (10.15), which is why you can read the discs on older versions of macOS. Here’s a good message from @Shamino in a good thread about the problem with some possible workarounds (although one, reading them on an old machine, you can already do).


If you have an older machine, and there aren’t too many problematic discs, then you might want to read them on the older computer and then burn a new disc using a format compatible with modern macOS.

I don’t know if burning an HFS+ format disc is something considered valid today.

Macs of all generations should be able to support ISO-9660 format. ISO-9660 limits filenames to the old 8.3 standard, but there are extensions for going beyond this. The Joliet extension was invented by Microsoft and is widely supported these days. The Rock Ridge extension provides support for many UNIX-specific file system concepts like symbolic links and file permissions. macOS should support both Joliet and Rock Ridge extensions (but classic MacOS 7 through 9 requires add-on software to support them).

If you want to burn a data-DVD (or Blu-Ray disc), you should use the UDF format, which is standard for DVD and BD media.

Third-party disk burning software (like Roxio Toast) should give you the ability to select the format you want to use. I’m not sure what format you will get if you try to burn a data disc from the Finder.

Your right, the unreadable disk is Mac OS standard. The MacAir M2 can read another disk that is Mac OS Extended. I think that is HFS+. So all I have to do is copy the MacOS Standard CD onto another formatted ISO 9660, Mac Extended, or something else more modern. But I am really surprised they dropped reading of HFS.

Blockquote I’m not sure what format you will get if you try to burn a data disc from the Finder." I am trying that from High Sierra right now and will report back.

With High Sierra I got MacOS extended (i.e. HFS+) will try Monterey tomorrow.

With Monterey, Finder formatted CD-R as MacOS extended (i.e. HFS+) too


Great to know. But it does meant that if you have a need for really old Macs to read the disc, you’ll need to burn the disc with third-party software.

HFS+ (aka “Mac OS Extended”) was introduced in Mac OS 8.1. If you think an older Mac may also need to read the disc, then you will want to burn your CD as ISO-9660. Support for ISO format goes all the way back to Mac OS 6 (maybe even older), as long as you have installed the corresponding system extension (which Apple bundled with the CD-ROM extension).

Likewise. It’s equally frustrating that this prevents modern Macs from mounting HFS-formatted disk images and HFS-formatted floppies (e.g. with a USB floppy drive).

I assume the HFS driver was 32-bit code and Apple didn’t want to pay for the development and support to port it to 64-bit. But I think it wouldn’t have cost them that much to port their read-only driver in order to allow mounting old volumes. But they didn’t ask me my opinion.

I’m more surprised that the macFUSE project (to add third-party file systems to macOS) doesn’t include HFS support. I can only assume that there isn’t a whole lot of demand for it.

FWIW, here’s list of supported MacFUSE file systems.

Some web searching did find fuseHFS, an unofficial MacFUSE extension for HFS. But this driver is beta, and the author considers it “hobbyist” quality. So I wouldn’t use it on any production system without performing lots of testing on another system. But so far, this is the only option I know about.

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Yes, dropping HFS sucks, but if there is a poster child for “technical debt,” it would be this. I understand why it wasn’t carried forward. Sadly, though, I have large CD-based clip art libraries that I still use, which are stored on dozens of HFS CD-ROMs. Eventually I bit the bullet and spend a day copying them to modern media for ongoing access.

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