Ahhh… the memories… Back in the day (around 1978), I had one of these beauties. All you had to do was place the telephone handset into those cups (really! ), dial up your favorite server, and Presto! You were on-line at 300 bits per second. And for only $139 – it was heaven!
While rummaging through my files, I came upon its (dot-matrix) printed manual, so I scanned it for posterity. Enjoy!
Photo credit: http://www.swtpc.com/mholley/USR/USR_Modem.htm
: Wait… What? You had to insert the handset into those cups? Why? AT&T insisted on this to “prevent damage to the telephone system” from third-party (unlicensed, untested, unreliable) equipment. Only after the Carterphone decision in 1968 would AT&T allow you to make any sort of electrical connection to the phone network. Before that, you could not connect your own telephone (you had to rent one from AT&T), or a fax machine, or a modem, etc.USR-310 Acoustic Coupler Manual