www.dl2rum.de

My 590 has an FSK input I'd like to use - is there a Mac digital app that uses the correct FSK keyline rather than audio output? It looks like Cocoa Modem, FLDigi and others that I have looked at use AFSK.

I can run other stuff in Parallels but I'd rather not. I've been lucky enough to have all my other digital apps work fine natively.

I always use real FSK. There are a lot of devices on the market supporting FSK. See microHAM: http://microham.com
cocoaModem support the OOK mode. A simple converter can convert these OOK signal to FSK.