How to transfer Classic Mac Pro Tools files to a modern computer without file corruption

How to transfer Classic Mac Pro Tools files to a modern computer without file corruption

Old Mac Pro Tools Sessions

In order to open old Pro Tools session files (from Mac OS8.x, 9.x, OSX 10.0-10.4, Pro Tools versions 1 to 5 with SD2 files ) in modern Pro Tools you need an old version of Pro Tools and save it, over several PT versions. Not everyone has access to old Mac computers that can run multiple old versions of Pro Tools. That is where we can come in to convert the old Pro Tools session files for you. But you must make sure the files' chain of custody is clean to prevent file corruption.

About Classic Mac files and how they are different

Classic Mac files should never leave the Mac HFS+ file system or they will be corrupted and no longer readable. Back in the Classic Mac days (1984-2002) Mac files were not required to have dot extensions to their file names to identify their file type. Instead they used the filetype and creator attributes. These were a set of 4 characters for each one that the OS would use to show the correct icon for a file, or to launch the right application when a file was opened directly from the desktop. Without them, an app cannot recognize a file and open it. You could see the filetype and creator by opening the file in ResEdit. These attributes are stored in what is called resource fork in the Mac HFS+ file system. While Macs of this era can connect to non-Macs computers file systems to transfer files through drive connections, FTP, SMB, these destination file systems (typically FAT32 or NTFS) did not recognize the resource fork, so when they are written from a Mac to these other file systems they are lost. This is why almost all Mac files of this era that were available over FTP or internet were either compressed in a .sit (Aladdin Stuffit) or .zip file. This compression preserves the resource forks of the files within. However, with the right tools, it is sometimes possible to restore the filetype and creator to Classic Mac files, and doing so will make most of them work again IF you know which ones to use, meaning you need to remember what app was used and you needed to know the filetype and creator attribute codes to apply. If the resource fork used other important data for the file, the file cannot be fixed even if you add the filetype and creator, which is true of SD2 files. We can do some amount of file forensics to figure this out when it is unknown. However, besides the resource fork containing filetype and creator, some also contained other important data. In particular, Sound Designer II (or SD2) files contained the sample rate, bit depth, and length of the file. This was the default audio file format option in early versions of Pro Tools. When an SD2 file loses this meta data it will be impossible for Pro Tools to load the audio into its session file. A guessing game can be played to convert the SD2 files to WAV but then they must each be manually relinked in Pro Tools. With some sessions containing hundreds of audio files this is very tedious and we charge a premium for this service in comparison to SD2 files that relink with no issues.

Classic Mac OS File Chain of Custody

What do we mean by "file chain of custody"? This is the journey the files have taken over their lifetime from the original computer they were recorded, to any of your storage drives, to any cloud service, and then on to the computers here at Deep Signal Studios.

Here are a few examples of clean chains of custody that a Pro Tools session, Studio Vision, Emagic Logic or Cubase VST files with SD2 audio tracks can take that will prevent file corruption:

  • A backup created between 1989 to 2004 on either Classic Mac (System 7.x, MacOS 8.x, MacOS 9.x) or OSX 10.0, to 10.3, and read by any MacOS (including OSX) from a CDR, DDS tape, DVD-ROM, external FireWire drive, or Mac HFS+ formatted USB drive (including USB Iomega Zip or Jaz) or other external USB hard drive like an orange LaCie drive, written with either Intel or PowerPC chipset, which is then zipped (.zip) or stuffed (.sit) on that same Intel or PowerPC Mac, and transferred over the internet or to a USB flash drive to end up at a large file transfer service.
  • All files (session and audio) compressed in a .sit or a .zip on a version of MacOS with either Intel or PowerPC transferred over the internet or on a FAT32, NTFS, Mac HFS+, or any other file system.
  • Files transferred from a SCSI drive on a Classic Mac an OSX 10.0-10.3 Mac over a local network or read with a PCI SCSI card, and then transferred to an Apple HFS+ formatted USB drive.

Examples of Chain of Custody of Mac files that will be corrupted:

  • Files that are not zipped (.zip) or stuffed (.sit) and uploaded to a large file transfer service
  • A Windows PC using special software to read Apple HFS+ external or internal storage drives of any type (USB, Iomega Zip or Jaz, CD-ROM, DVD-ROM, FireWire, internal IDE drive) which are then copied to the internal Windows hard drive or zipped directly from the external storage drive.
  • Copying files from a Mac internal or external drive to a USB connected FAT32 or NTFS hard drive, and then attempting to use them ever again on another Mac.

Sending DSS your Pro Tools files from the 90s

ALWAYS zip or stuff (.sit with Stuffit) your files on your Mac before uploading them to a file sharing service to send to us. Never send upload them unzipped, they will not survive. Mac Pro Tools files made with PT 1 through 8 should have always been stored on a Mac HFS+ file system during their lifetime, like a hard drive, CD-ROM, DVD-ROM, DVD-RAM, DDS tape. If they were ever stored on NTFS, ExFat, or FAT32 (Windows file systems) they will be corrupted and the session file cannot be recovered. When they are uploaded to the cloud unzipped, they are written to one of these file systems and become corrupted. The sd2 audio files can be converted but if you made edits it will be painstaking to reassemble the hundreds of audio files some sessions have without the session file. If the session file is not zipped, it will be corrupted as well.

DO NOT TRY TO OPEN VERY OLD PRO TOOLS SESSIONS in current Pro Tools that do not have file extension by adding .ptf or .ptx, you will damage the file! Just get them to us using Usendit, Dropbox, Wetransfer, Starchive, etc. You must Zip them first. If you use Google Drive use the option to share with anyone with the link. If they are on a PowerMac, G3, G4, any other Mac who's browser cannot connect to the modern internet DO NOT move them to a current computer by using a USB flash drive that is not formatted for MacOS in HFS+ UNLESS you zip the files first. Most USB flash drives are formatted in ExFat or FAT32. While early version of OSX can read these, copying native Mac OSX files to them without formatting them in HFS+ first will corrupt the files unless they are zipped. You can use the Disk Utilities app to format a USB Flash Drive to the HFS+ Apple Mac file system but you will need to zip the files on a Mac, regardless.

If you wrote the files to a CDR or DVDR with MacOS 6.x, 7.x, 8.x or 9.x and possibly OS X 10.0, 10.2, 10.3, they cannot be read by macOS 13 Ventura (and possibly macOS 12 Monterey) on an M1 or newer Mac. You will either need to find an older Mac or send us the disks. If you can find an Intel Mac with macOS 15 Catalina or earlier it can read them, copy the files to the hard drive and zip them. From there, you may use the same Mac to upload the .zip file. You can use any USB flash drive in any file system to copy the zipped files so you may bring it yo to another computer for upload, even a Windows computer. This will need to be done in situations where the Mac is so old that its browser browser, even the newest ones that can run on that particular OS, cannot access modern websites because the internet security standards are incompatible.

If you have hired a forensic HD data recovery service to perform unarchiving from an obscure tape storage format or from a crashed or physically damaged hard drive PLEASE ask them to read this page. We know from experience that even they get this wrong sometimes.

If your Pro Tools session files have one of these icons below that is visible in current MacOS (or still using a machine from that period) they, along with your SD2 files, will probably be OK as long as you zip them. Pro Tools Windows session files will not have any of the above problems.

Pro Tools 4 Pro Tools 4.2 Pro Tools 5 Pro Tools 5.1