The new version 3.0 bring you new features an some bug-fixes New Features/Bug Fixes (in version 3.0):
* Added OpenGL rendering for improved performance and improved compatibility with OSX 10.4 and above.
* Added Printing to a choice of 3 simulated legacy printers, with output to PDF files.
o Epson FX-80 – Text and Graphics dot matrix printer supported by most later Atari software.
o Atari 1020 – Color printer/plotter.
o Atari 825 – Early Atari dot matrix printer included for use with early Atari software.
* Added Function Key window to allow user to press Atari Start, Select, and Option keys from floating palette.
* Added enhancements to the built-in debug monitor.
o Ability to run in Fullscreen.
o Command history
o Read/Write emulator memory from/to Macintosh files.
o Read/Write emulator memory from/to Atari disk image sectors.
o Memory Move
o Bank Switching (XE)
o Complex Breakpoints
o Instruction Tracing to Files
o Improvements to the History command
* Added the ability to create blank Cassette images.
* Added the following features from Core Emulator version 1.3.6+
o Loading of BASIC files from Loading executable file menu item
o Added new Atarimax cartridge types
o Bug fixes
* Added Fix for Sound issues on certain classes of machines. Sound should now be much more stable.
* Added Fix for Atari control key not working properly when using international keyboard mapping.
* Added Fix for some Preferences not getting saved when changed by emulator menus.
* Added Fix for bug where screenshots taken in 16 bit colors would be all black.
* Added Fix for garbage being displayed in emulator window after retuning from Fullscreen.
* Added Fix in Disk Editor for issue recognizing Atari Dos type on some enhanced density disk images.
Details gibt es hier: http://members.cox.net/atarimac/