This instructable only details software games. If you have something on a floppy disk then you'll need hardware to put it on.
Step 1: Get a game
Step 2: Get DOSBox
Step 3: Run boom on dosbox
1- wherever you put Boom when you downloaded it, go to it. Right click boom and click"get info. "
2- in the "open with" menu, go to "other" and a dialog box in the applications folder opens up. Some apps are grayed out. Up at the top where it says "reccomended applications" click that and switch it to "all applications."
Step 4: Place your doom.wad in the right folder
Step 5: Launch Boom and you're good!