Dad found an old floppy of Slay the Mighty Dragon. It’s a text-based adventure game he and I coded in BASIC when I was little. I’ve made the game and a BASIC interpreter available for download here. I would suggest DOSBox to run it. It’ll work in XP, but the sound or a text setting in the ending might not work correctly. If you don’t want to use DOSBox, decompress somewhere, double-click on prog.com and skip down a paragraph.
To start with DOSBox, download, install, and run it. Decompress the zip somewhere, the root of a drive would probably be easiest, or somewhere with short folder names without spaces. Apparently DOS, and DOSBox by extension, has trouble handling spaces or names longer than eight characters. I’ll assume you’ve decompressed it to C:\mightydragon. In the DOSBox prompt, enter mount c: c:\mightydragon, then c:. You should now be at a C:\> prompt. To start the BASIC interpreter, enter prog.com.
You should now be in the BASIC interpreter. Press F3 or type LOAD”, then game.bas. Press F2 to run it. If you’re running with plain ol’ XP DOS emulation, the sounds will probably try to use the PC Speaker on your motherboard, which may or may not work. If you’re using DOSBox, the sound will use your speakers. If you finish the game you’ll probably just have to close the window. I can’t figure out how to exit the BASIC interpreter. Have fun!