Apple Intelligence is now available on iPhone, iPad, and Mac!

📢 Newsroom Update

Apple introduces M4 Pro and M4 Max. Learn more >

Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

5 each CDRs burned 2001 will not open

In 2001 we backed up certain folders from the HD of a PPC Mac G3 to five (unbranded) 800 meg discs using, most likely, the Toast application. Today when attempting to open the discs to retrieve some archived business related files, I get the following message depending on which iMac I'm using.


On an iMac 27" running Sierra 10.12.6 when I insert the disc the message reads: "The disk you inserted was not readable by this computer." Note, however, that Disk utility recognizes the iMac internal "CD style" drive.


On an iMac tangerine running OS 9 the message reads: "This disk is unreadable by this computer. Do you want to initialize the disk?" Name field shows: untitled, the Format field: ProDOS zero K (It shouldn't show zero K because the 800 meg disks should be full of data.)


Naturally I don't want to initialize because I'm hoping to access folders and documents from these discs.


Is there some resource I should have on the 27" iMac 10.12.6 and/or on the Tangerine iMac OS 9.2.2 to enable the discs to open?


Attached are screenshots of an actual disc (#1) plus screenshots from the iMac Sierra 10.12.6 (#2) (#3)and OS 9.2.2 (#4)


Any suggestions on how, if possible, I might retrieve the files on these discs will be greatly appreciated!

iMac 27″, macOS 10.12

Posted on Jun 10, 2024 12:15 AM

Reply
Question marked as Top-ranking reply

Posted on Jun 10, 2024 4:08 PM

Apple dropped all support for the HFS (no "+") filesystem in Catalina and later.


Reportedly, Macs running Catalina and later will reject all optical discs that have HFS filesystems on them, including hybrid discs that were explicitly written with two filesystems so that they could be read on a Windows PC. Although the modern Macs might be capable of reading the filesystem meant for Windows PCs, when they see the HFS one, they choke and reject the disc.


Thus if you have an old optical disc written by a Mac that is in perfectly good condition, you might have more luck reading it on a Windows PC than on a modern Mac. A truly sad state of affairs.


------------------------------


Quite apart from that, CD-Rs don't necessarily last as long as people thought they would. The aluminum layer on a factory-pressed CD or DVD may last a long time – but the dye layer on a recordable disk might deteriorate after 10 years. You say that you burned your discs in 2001 (about 23 years ago), so it is possible that they have gone bad – especially if you have been storing them in any place where they would be exposed to a lot of heat.

11 replies
Question marked as Top-ranking reply

Jun 10, 2024 4:08 PM in response to sgcnostromo

Apple dropped all support for the HFS (no "+") filesystem in Catalina and later.


Reportedly, Macs running Catalina and later will reject all optical discs that have HFS filesystems on them, including hybrid discs that were explicitly written with two filesystems so that they could be read on a Windows PC. Although the modern Macs might be capable of reading the filesystem meant for Windows PCs, when they see the HFS one, they choke and reject the disc.


Thus if you have an old optical disc written by a Mac that is in perfectly good condition, you might have more luck reading it on a Windows PC than on a modern Mac. A truly sad state of affairs.


------------------------------


Quite apart from that, CD-Rs don't necessarily last as long as people thought they would. The aluminum layer on a factory-pressed CD or DVD may last a long time – but the dye layer on a recordable disk might deteriorate after 10 years. You say that you burned your discs in 2001 (about 23 years ago), so it is possible that they have gone bad – especially if you have been storing them in any place where they would be exposed to a lot of heat.

Jun 10, 2024 5:17 PM in response to sgcnostromo

You can try using a Linux system to see if it can read the CDs. Linux is able to read the old Apple file systems, although with some distributions the necessary drivers and/or software may need to be installed from the Linux distribution's software repository.


The easiest option may be to create & use a bootable Knoppix USB stick. IIRC, Knoppix has the older Apple file system drivers installed by default, but it has been a while since I tried to access the older Apple file systems. Knoppix should be able to boot any 2007 to 2015/17 Mac (without USB-C ports & do not use a 2006 MacBook with the 32bit Core Duo CPU or it may damage that specific model laptop), or most any PC using a decent CPU. Booting from a Knoppix USB stick should not affect the data on the internal drive because the Knoppix default is not to automatically mount any volumes. If you try to boot a Knoppix USB stick on an Intel Mac, then you must give it time to boot since the Mac may appear frozen on the Apple boot picker menu due to how Knoppix boots & the Mac's very limited firmware. It can sometimes be tricky getting a Linux USB stick to boot to boot on some UEFI booting PCs due to poor UEFI implementations for selecting boot media. It is possible to boot recent versions of Knoppix even if the PC has Secure Boot enabled, but you must select the proper bootloader file (I think it may be the bottom one on the list of boot files).


You can try using data recovery software to attempt to recover the files if the CDs are damaged.


Jun 16, 2024 8:42 AM in response to sgcnostromo

Try using the v9.1 Knoppix .iso file with "EN" in the name for ENglish. Either the CD or DVD version should be Ok although the DVD version will contain more items, but IIRC the CD version used to have the necessary drivers installed by default. Even if they are not installed by default, it is easy enough to install them if using the most recent version of Knoppix.


To create a bootable Knoppix USB stick you can use the downloaded Knoppix .iso file as a source for Etcher (Mac, Windows, Linux). Or you can burn the .iso image to a CD/DVD (you do not burn the .iso file to CD/DVD, but burn the contents of the .iso file to the CD/DVD). It has been over a decade since I burned a CD/DVD, but on macOS I believe you need to use a third party app such as Toast since macOS is usually unable to mount or process Linux .iso files.


The other Knoppix files listed are used to confirm the integrity of the .iso file to make sure the download process did not corrupt the file & the file has not been tampered with after creation. You need to use a utility to create a hash of the downloaded .iso file & compare it to the respective file.....macOS & Windows both have built-in command line utilities to do this. The files with "DE" in the name are for German (DEutche).




Jun 10, 2024 10:40 AM in response to sgcnostromo

CDs or DVDs?


Regardless of formatting, burnable optical disks are not permanent. They are not like "pressed" app, music and movie disks. Burnable disks have photo-sensitive dyes that will degrade with time. This article has a very good illustrated explanation of the difference between pressed CDs and writeable ones. Very different technologies:


http://techref.massmind.org/techref/cdrs.htm


This one:


https://www.howtogeek.com/682807/the-cds-you-burned-are-going-bad-heres-what-you-need-to-do/


has some info and storage recommendations which says UV light can degrade the writeable layer and cause loss of data. Other source find that, with proper storage, burnable CDs can last up to 100 years; with improper storage they can be useless in as short as fve years. Yours are 23 years old.


Where were they stored? I hope you don't say "the attic." 😱

Jun 14, 2024 12:29 AM in response to HWTech

After checking out your Knoppix link, I have an old but fully operative c.2006 Gateway laptop running Windows XP with a working CD/DVD drive. As you wrote: "...or most any PC using a decent CPU. Booting from a Knoppix USB stick should not affect the data on the internal drive because the Knoppix default is not to automatically mount any volumes." If that Gateway PC will open the ProDOS burned disks, I might retrieve something even if only the high res product photographs catalog text info.


Anyway, I want to give it a try. However... after looking at the Knoppix site I haven't the foggiest notion of what I need to download to the USB stick given the numerous links and file sizes from apparently all over the world. Any suggestion where I mighty access a beginner's primer on how Knoppix works? I'm no technician and won't be offended if you suggest I'm over my head.


Thank you for any opinion. Best Regards. SC

Jun 14, 2024 8:44 AM in response to sgcnostromo

Regarding picture #4: This does not have to mean that the discs actually were made in a ProDOS format. I have earlier noticed the same message with an old CD-R that refused to be recognised. After many more attempts, it finally appeared as a readable Mac OS Standard disc on the Desktop of a Mac OS 8.6 iMac G3. So, you could perhaps check whether inserting a CD ten, twenty, or even thirty times would change anything.

5 each CDRs burned 2001 will not open

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.