Sad but true.
I went to work for a company in 1995 that was still using PDP11 as their primary language on old DEC machines. This was a commercial application suite. They got their spare parts at garage sales in the area (yes that is what they did, literally!). My last project was to read a bunch of old 9 track tapes to try to find the source code for a program that needed to be modified.
I put up with that for 5 months and bailed to a much better, higher paying job using C on AIX. I was never so glad to leave a company!