I pre-date PC's. The first computer I used was my high school's main frame. The Terminal was a telex machine. We typed in our program into the telex machine and produced a tape. We then dialed up the main frame and ran the tape to load the program and the data. Kept our fingers crossed that there were no typos.
FYI, this class helped me get my first full time job with Maersk Line. Where the terminals weighed about 60 pounds.
Ellen