Vampire computers: They're a thing.
Let me try to explain. As long as there have been deep simulation games, people have been creating pretty wild things in them. How they do it is usually more interesting than the object itself. A word processor is boring. A word processor made inside Minecraft using thousands of redstone blocks? Pretty rad.
Dwarf Fortress players have long been just as wildly inventive—the Dwarf Fortress wiki even has a page for Computing, explaining how to use the game's pressure plates, open or closed doors, animals, and other elements to reproduce binary code.
As I learned recently by talking to Dwarf Fortress creator Tarn Adams, vampires actually make for very effective computer operators. When I asked what could make for a really ridiculous, obscure Steam Achievement for the upcoming Steam release of Dwarf Fortress, this was not what I expected (then again, I never really know what to expect from Dwarf Fortress).
"Ah, geez. What is the strangest thing that can possibly happen?" Adams said with a laugh. "People have those vampire computers. We can encourage them—like if a vampire steps on a pressure plate, we can get them into computer processing that way."
I needed to know more, obviously. Adams elaborated.
"The perpetual vampire computers. They don't need sleep or food, right, so they can run your computers forever if you draft them into the military and then have them walking patrol patterns. They're much more reliable than animals are, as a computer operating method."
I can't find video evidence of a vampire-based computer, but I'm guessing Adams has seen some wild creations in the 13 years Dwarf Fortress has been available. There is, at least, ample wiki documentation about using vampires as immortal lever-pullers (apparently they're also great bookkeepers, as long as you prevent them from going insane when their clothes rot away).
If you've built a vampire machine in Dwarf Fortress, please share it with us. The world needs to see. Meanwhile, here's a video of Space Invaders built inside Dwarf Fortress.