I was recently sent an email, requesting information on how to get DOSBox to support certain screen resolutions – the problem being that the proprietary DOS application uses direct screen writes, and, sadly, DOSBox’s CGA driver just can’t handle it. It comes out looking like an Apple ][ color monitor had the fits.

After a few hours of muddling through code, I had a revelation: QEMU. It’s leaps above DosBox in emulation – heck, I use it to test my custom BartPE builds (anti-Spyware/Virus/Cleanup/Backup) images.

Finding that there is already a MacOS X port sent me off to do my “good deed”. The first major problem being that qemu is not only eclectic command-line fu, but it is dynamically linked.

I created a stock MacOS X .app directory structure, wrote a shell script, moved things around, and after a bit of twiddling with install_name_tool, and the magic of dirname, my application was ready.

I installed FreeDOS to a 10M virtual disk, put the SignWriter application on it, setup a CONFIG.SYS and an AUTOEXEC.BAT… stuffed it, and viola!

The glories of monochrome CGA, half sized, running on my ancient PowerBook. Now accessable by a single icon click. Full screen mode is achieved with Ctrl-Shift-F. Via la Mac revolution!