Maybe I wasn't clear in the description....
All the disks with their files mount on the Mac and list properly via PC Exchange in the AFE control panel. I can load any of them into Cubase 2.0 Score, VST 4.0 or VST 5.0 on the MDD. No problems. One would think that once I saved them on the Mac as an Arrangement or Song, I should then be able to load them into Logic. Not true as far as I can tell.
You don't need an internal floppy drive. The Mega 4 Atari disks are DOS format, so they mount straight away on the Mac via USB floppy drive. Logic will see the original files on the Atari disk and also see them once I've loaded them into Cubase on the Mac and re-saved them on the Mac, but Logic will not load them in either format.
Problem here is not the disk format or drive. Problem is Logic won't load them without crashing, freezing, etc. Logic says, "Come on in." But door is locked...
So to put the question another way... Has anyone ever loaded a Cubase file of any type into Logic?