I've been reading a bit about the upcoming Firaxis XCom update and I've been getting a hankering to play the original X-Com. Well, I played it on the Playstation 1, I don't know if I have the disc anymore and even if I do, that's going to be annoying. I had a mouse for the original PS1, but who knows where that is, and who knows if I can even connect it to my PS3. I don't think I've got anything to connect a PS1/PS2 controller to my the PS3. (I know I did have a gizmo for moving Memory Cards over but I don't recall if it had a controller port.) And even if I got a mouse to work somehow … I don't want to play it in my living room with a mouse on the coffee table.

Anyway, a big hat tip here to my friend Tony who had mentioned to me at some point in the past that if you buy X-Com on Steam that it just ships inside an open source project called DOSBox. And you can download a version of DOSBox for OS X. So this morning while I was watching the Apple liveblogs I did all this. It works, but there are a few tweaks I had to make to make things convenient. Here's what you do.

Buy X-Com on Steam. You can get the first game for $5 or a whole bunch of them for $15. I don't know if you can actually do this from the Mac Steam client, I did it in a Windows 7 virtual machine.
Install DOSBox. Download it, and then put DOSBox.app in your Applications folder.
Copy the files from Windows to somewhere useful on your Mac. I made a DOSBox folder in my Documents, but wherever works for you. Assuming your Steam is working in the default place you want to copy the folder C:\Program Files\Steam\Steamapps\common\XCom UFO Defense.
When you get into DOS that long file name is going to be a pain. I renamed the folder to just XCom – so I have ~/Documents/DOSBox/XCom.
At this point you could just run DOSBox manually, mount the folder, and run the stuff, but there's a better way and that involves a dosbox.conf file. The folder already contains one but you need to pass that to dosbox, and that's a pain as well. Here's the whole command that I use:
/Applications/DOSBox.app/contents/macos/dosbox -conf /Users/tsanders/Documents/DOSBox/XCom/dosbox.conf
This file didn't completely work for me. There was something not right about fullscreen mode but I didn't want the app in fullscreen on my 27" monitor anyway. The conf file also defaults to a 2x interpolation and I wanted to use the 3x. Lastly the volume was way too loud for me. So here's a list of changes I made:
- Comment out fullscreen=true (so #fullscreen=true)
- Change scaler=advinterp2x to scaler=advinterp3x
- At the bottom in the [autoexec] section change the mount command to the proper path. Mine is mount c /Users/tsanders/Documents/DOSBox/XCom -freesize 1024
- Add the line "mixer master 25:25" to set the volume levels 25% of maximum
OK, so far so good but that command line is a pain in the rear to enter. That's easy to fix! Run Automator, select the Application type, then in Utilities pick a "Run Shell Script" action. Paste the command over the line that says "cat". You probably don't want Automator to wait for the command to complete, so be sure to add " &" at the end of the line.
/Applications/DOSBox.app/contents/macos/dosbox -conf /Users/tsanders/Documents/DOSBox/XCom/dosbox.conf &
Save the resulting Automator action in your Applications folder and you're done!
Optional bonus step: Go to images.google.com and get a nice icon image - I just looked for "x-com ufo defense box". Find the app you made in the last step, select it in the Finder and hit cmd-I. In the info window that comes up you can select the icon (it should be the little Automator robot) and just paste an image from the clipboard.

At this point you have an icon in Finder you can double-click, or something you can launch from Spotlight. No more opening Terminal, navigating to the proper directory, or remembering the syntax of the DOSBox commands. Pretty cool.

In theory this ought to work for a large number of DOS games. Of course, the devil is really in figuring out the proper settings for that DOSBox config file. That's where the cool part is that the Steam file is already mostly correctly configured. (I didn't chase the fullscreen problem but I suspect it's related to having two monitors, it might work fine with a single monitor.)

Edited to add March 7, 2012 10:21 PM:When I was working on this I had Automator open and I didn't notice this but the first version of the Automator app continued to run until I quit the game, resulting in a turning gear icon in the menubar. The fix is simple: just put the command line into the background with a simple & at the end. I adjusted step 7 to reflect this.