I didn't know that about -RW discs having a less refelctive layer, but that would make sense with older drives having problems reading them. Might just have been a lucky incident or something. It's still a puzzle why burning audio on the CD-RW worked, and yes -I deliberately chose to close each session when burning. The CD-R discs say '48X' on them which I assume refers to the maximum burning speed (probably faster than my Superdrive can handle since it chose 32X). I chose the lowest speed first (4X I think) and when that worked OK I tried the maximum speed (32X) for the next one which also turned out perfect. I tried burning with one of my preacious CD-R discs (I only have a few of them left and needed them all for this project) and it worked perfectly right away! It looks like the write speed is determined by the disc itself, not the drive. If someone thinks Toast could solve the issue I could probably install a lower MacOS version on an external drive in order to re-install Toast, but I'd rather not if there are simpler ways to do this.

I did buy 'Toast' a few years back, but it's not compatible with High Sierra. Write Strategies: CD-TAO, CD-SAO, CD-Raw, DVD-DAOĪnd refreshing the above after inserting a CD-R disc: The Superdrive in my Mac Pro is, according to System information (when inserting a CD-RW disc):ĭVD-Write: -R, -R DL, -RW, +R, +R DL, +RW So I came across the Open source Burn which seems to do everything I want except I don't get to choose between any other speeds that 4x. They have a tendency of removing useful features which they consider 'outdated' The CDs work fine on the Mac though.Īctually it's been a while/several MacOS versions ago that I burnt a CD and had trouble finding options for doing this in High Sierra -so I gather Apple have either trimmed down this feature, hidden it very well, or removed it altogether.

I'm trying to burn some CDs on my Mac Pro (10.13.6 High Sierra) which are to be used with a vintage 80's computer, but they can't be read there despite using the correct format (ISO-9660/Joliet). Are there any apps which allow me to burn data CDs at the lowest possible speed (1x)?

Toast for mac 10.13