Earlier quoted context omitted.
Bad, old memory: "Every transaction must have a line written to the printer" Tracking down "why is the antique system suddenly slow". Power went out, system came back up fine, everything but the one ancient but vital app is fine. Dig, dig dig, there's this old dot matrix printer in another room (because it used to be loud and annoying) that no on has fed or looked at in years. It finally died with that outage, and it…
Holy cow how old was this system, circa 1975 or something?
I'm pretty sure it was the only dot matrix printer with a serial port i ever saw. Even daisy wheels were parallel port by the time this went in; but they had a like 50ft cable to move it to the other room. Someone worked hard and paid large to set that up originally.