My grandfather purchased a niche customer management DOS application in 1986 or so and used that Software up until the day he died in 2012.
When he was finally forced to upgrade to a computer without a parallel port, he was a bit stuck for a bit because the software would only print to a printer connected via parallel port. I couldn’t find a card for this at the time, for whatever reason, but I eventually was able to trick the software into printing to a modern printer and I had never seen him more happy since it saved him the $3000 software upgrade fee.
When he was finally forced to upgrade to a computer without a parallel port, he was a bit stuck for a bit because the software would only print to a printer connected via parallel port. I couldn’t find a card for this at the time, for whatever reason, but I eventually was able to trick the software into printing to a modern printer and I had never seen him more happy since it saved him the $3000 software upgrade fee.
Miss you, Grandpa!