For some users, the iMac can be problematic with serial interfaces and earlier versions of software. To use MOTU software with an iMac, MOTU recommends updating to later versions of software:

Digital Performer 2.6 or later
Performer 6.03
Mosaic 1.58
Unisyn 1.52
FreeStyle 2.11
FreeMIDI 1.4 or later
(or later)

These versions of software have USB support and do not require floppy authorization disks (*with the exception of Mosaic 1.58).

*If you encounter authorization problems with an iMac and Mosaic 1.58, please contact MOTU technical support at (617) 576-3066 or email techsupport@motu.com