I started in the late 70s in oil and gas exploration, Tech work on collecting information on drilling activity and other geological first looks and testing. Learned how to type reports and setup "blue line" graphics. Used pen and ink mechanical drawings on velum paper, copied them to a sheet of yellow photosensitive paper, then submitted the yellow line paper to ammonia vapors to develop the blue line copy. Next used a "telecopier" to transmit blue line to a receiver that redrew the copy for the home office. Used a regular telephone to call the office, the office person (secretary or whomever) would connect their phone line to the telecopier device and the ink pen would redraw the original. It was all spinning cylinders of paper on each end. Was quick too. This all before there were any telephone computer connections.
Graduated in late 80s in electrical engr. Started seeing the automation of industrial production in pulp and paper industry, steel, carpet, pharmaceutical, petro chemical, agricultural storage and shipping, power generation, raw material storage and transportation even mining. The computer (IT) jobs I worked on were across the industrial production and processing industries. Got to see and work in many different environments.
Early environments were located in basements, closets, electrical supply rooms, warehouses, etc.. I did not really see quality control rooms till real early 90s.
My "office" was really the spare parts room. Lots of part cabinets and shelves. Tools everywhere, punch cards, "bootstrap" paper tapes. I remember being impressed with magnetic core memory.
You could smoke almost anywhere inside. Since I was rarely needed or wanted in the main office, I could wear a shirt without a tie, even bluejeans if I was scheduled for maintenance tasks.
Worked a pager system owned by the company. Always on call 24\7, even vacations. You were the computer "doctor" and if it hiccupped, you were called.
I remember the time when computers were unguarded, even the plant facilities. I would get a call at 2 am to check something out, would drive over and park my car walk past a guard shack without so much as a wave to the persons inside, open and close gates, doors and so on until I was in the "computer room". Then get started with the error codes or messages. No logons etc.
What a different world it was back then.