Its titled 'AT&Ts 60s modem that won't die' and is really informational on both modems of 'our time' and before. Well... for some of you maybe right on time... at any rate, CRD takes a deep dive on how the very first modems operated and talks a little bit about the later Hayes Standards, too.
Worth a watch - it had me smiling... I never got to use these earlier modems as I started on the Hayes set... but it was neat to learn how folks might 'BBS' before it was easy. :P Take a gander.
Furthermore, if you have a Bell 103 300baud modem, he even setup a POTS phone line that you can get a messasge from:
If you have a Bell 103-capable modem, call this number for a special message: 509.569.7985
Set your serial port to TWO stop bits, not the usual one!