What was your first modem? Mine was a 300 baud VICMODEM for my Commodore VIC-20 which included a type in terminal program in the user guide.
You had to manually dial the number with the phone, unplug the coil cable from the handset when you heard the carrier, and plug it into the modem!
@jimfl Nice! Love the design.
Mine too was a TRS-80 Modem I. Although mine is white (like the Model 4) not 'battleship gray' or 'Mercedes Silver' (like the Models I, II, III and 16).