This is a fascinating video of Circa 1964 Livermore Data Systems "Model A" Acoustic Coupler Modem.  What is most fascinating is that our intrepid tinkerer, K.C., had the modem but then he had to scrounge for the other pieces necessary to enable his experiment.

1. The Serial Adapter.
2. The circa 1980 phone.

So above and beyond the modem itself, all the other pieces are leaving the world as well.  His observation about how the USB port wouldn’t send the correct voltage to change the tone of the modem appropriately is telling.  Does your computer have a serial port on it?

I especially love the technical equipment necessary for completing the job.

exhibit a

Check it all out at phreakmonkey.com