Reminds me of a story: I ordered a soundcard for an engineers workstation. Had problems with accounting about this. What does he need a Soundblaster for? Well, he actually needed a joystick for his CAD package!
I used to have to unplug the printer from the parallel port so I could plug in my first MP3 player and transfer MP3s I had totally legally acquired in 1999.
The parallel port scanner that made your entire computer able to do absolutely nothing while scanning. No mouse input, no display update. An absolute time warp for your CPU.
I think my old Logitech from around 1995 plugged into the COMM port.
Why are you surprised? The only ADCs in you computer were on the sound card, and a joystick was just two potentiometers and a couple of push button switches.