I retired from teaching this year (2020) after thirty years in high school. When I started teaching, we still typed everything on electric typewriters and then had someone in the office run copies on a mimeograph machine. (I can still smell that warm ink!) The coolest technology I used was a reel-to-reel movie projector and a filmstrip projector that advanced by itself instead of giving me the beep to advance it.
From that first year in 1989, I saw the projector morph briefly into a giant laser video disc (the size of a record album), and then into the DVDs that I air-played onto my Apple TV. At one time I had purchased my own LCD projector since we had only a few in the whole school for teachers to check out. Now, it sits on a shelf because nobody wants it.
I spent a lot of time in the early nineties confiscating pagers, since only doctors and drug dealers needed to carry them. Later I told kids that they were crazy if they thought I could not see the glow of their forbidden cell phones in the dark half hour before school started. However, in the last few years I kept an iPad in my classroom for kids to use during class when they did not have a phone of their own.
I have always dreaded having to call parents - as probably most teachers do. When I started, I had to go to the clinic or office to get parents' phone numbers and then to a workroom to find a phone. Eventually we got phones in our classroom, and one of my favorite discipline techniques was to look up the parent's phone number on my electronic gradebook and call them from my classroom during class: "I just thought you'd like to know what your son is doing in my class right now. Oh, of course you can talk to him!" Covid-19 and distance learning raised my game even higher, though, when I got my Google Voice number and could then text parents from home. I really wish I had had that sooner!