First post, by emendelson
I'm not sure anyone can use this, but I put together a DOSBox system for OS X that works like this:
DOSBox for OS X has been "wrapped" inside an AppleScript app (called DOSBoxApp) that launches DOSBox. When you launch the AppleScript app, DOSBox opens, with drive C: as a folder inside the AppleScript app and drive D: as the OS X desktop.
If you drop one or more files on the AppleScript app (the icon, not the DOSBox window), those files get copied into drive C: in DOSBox. If DOSBox is not running, the files get copied into Drive C: and then DOSBox itself opens. If DOSBox is already running, the files get copied into drive C: and are available for use.
When DOSBox starts, it runs a batch file in drive C: named COMMANDS.BAT. You can drop a text editor into Drive C: and use it to edit COMMANDS.BAT so that programs run automatically. If you want to get files out of Drive C:, just copy them from DOSBox to drive D: (the OS X desktop).
Again, I don't know if this any use to anyone, but here it is anyway (EDIT: updated link, 2018; new version 10 Oct 2018):
http://www.columbia.edu/~em36/DOSBoxApp2018.zip
EDIT: See a message dated 10 Oct 2018 for details of this new version.