1) Open Terminal, drag in the DOSBox unix exe (located in DOSBox.app/Contents/MacOS/ by right-click "show packet content").
2) Create a folder daghd (to be used as Drive c: ) anywhere at your hard disk, drag it into terminal (to see the command line as shown in daghd.png.
/Volumes/pathtodosbox/DOSBox.app/contents/MacOS/dosbox /Users/yourname/pathtodosbox/daghd/
This is the first part in the long line of Terminal command.
3) add " -c mount d "/volumes" to the line (w/o enclosed quotes, just the quote left from /volumes).
4) drag in the unstuffed demo folder, enclose it with a quote.
-c mount d "/Users/yourname/pathto/Dag/". The command line should read like this:
/Volumes/pathtodosbox/DOSBox.app/Contents/MacOS/Dosbox /Users/yourname/pathto/daghd/ -c mount d "/volumes/Users/yourname/pathto/Dag/"
5) do not press enter, but add " -t cdrom -label \"dag\"" after the line.
/Volumes/pathtodosbox/DOSBox.app/Contents/MacOS/Dosbox "/Users/yourname/pathto/daghd/" -c "mount d /Users/yourname/pathto/Dag/ -t cdrom -label \"dag\"" -c frameskip=10
I added -c frameskip=10 here, otherwise you'll have to look the intro screen for a long time. If frameskip=10, you can install alomst immediately.
All this will mount the daghd as drive c and the downloaded and unstuffed zip file will be mounted as CD ROM drive (as drive d: in this example)
Be sure, your path to the emulated CD ROM doesn't include space bar (' ').
6) Press return to start the DOSbox
7) Type in "d:", then "install".
Since all files are stored at your hd, you can choose minimum install.
For me, it starts now.
Once installed this way, you can add the demo to your frontend.
In this case, choose /daghd/dagdemo/dagdemo.exe as drive c: and you need still the /dag folder as CD ROM drive to run the demo.
This is the point I must give up, because I don't managed to run this demo by a frontend, mostly the one i created. But for now, I found an error in it which doesn't mount any other drives than C:, when running a game from the games list. Fixed the problem in the source code, but the demo still asks for its cd (the folder "/dag"), if started from insde the frontend even the "CD" has been mounted.