I was an IT tech in college, and one of our biology professors had a stack of ancient computers in a closet specifically because the electron microscope in his lab had to have a computer as a controller connected to it that ran Windows 3.1 and which had extremely specific hardware specs. He’d Frankenstein them together as parts quit, and was always on the lookout for this very specific computer on eBay. I had to get his microscope back running once by installing Windows and the controller software on the “new” computer, and it was actually really enjoyable. Brought back a ton of memories. But yeah, he is just buying time until his perfectly good microscope quits working all because he ran out of parts.
Compaq or Dell. Similar situation with microscopes. They required FireWire to work.
