1200 would have been unbelievably fast in 85. Try 300 acoustic couplers. I was a student lab tech in my high school in 83 or 4. Being the ahole I was, I’d walk into the lab and whistle loudly fully knowing that everyone’s terminal would freak out with line noise. BofH indeed.
I have to disagree with your timeframes a bit at least for home PCs. I never had an acoustic coupler but I had a 1200 and subsequently faster modems starting in about 1983. I did use acoustic couplers on teletypes in the mid 1970s.
I'm not surprised that a high school computer lab would have been lagging by a few years. I'm guessing I was at a 1200 direct phone jack modem connection in 1985 (which would have been my first modem).
