From Mark Grebe:
Sio2OSX is a peripheral emulator for the Atari 8-bit computers that allows the Atari computer to use an OSX based Macintosh as a disk drive, a cassette drive, and a printer. Sio2OSX peforms functions similar to APE or SIO2PC on Windows based computers. Sio2OSX is a shareware program, and must be registered for full operation. The unregistered version of the program will run for 5 minutes before quiting, allowing you to verify operation with your hardware setup before purchase. The software can be easily registered for $25 through Kagi. A full manual is included within the application's Help menu. Note, as this does require serial USB hardware, and is a new product, please try it out on your hardware before you pay the registration fee. I'll be glad to answer any questions you might have by email.
What's new in this version:
VAPI and PRO image capability added!