Sportster 28.8 V.34 data/fax modem

Supports ITU-T V.34 at 28.8 kbit/s and V.32 bis at 14.4 kbit/s. Backwards compatible with slower speeds down to 300 bit/s.
2 RJ11 phone jacks: one for connection to the telephone wall socket, the second for connection to an analogue phone if required.
25-pin socket for connection to computer serial port.
Volume control.

7 LEDs indicate: AA, CD, RD, SD, TR, CS and ARQ/FAX.

8 DIP switches control the following options:
1. Data terminal ready override
2. Verbal/numeric result codes
3. Result code display
4. Command mode local echo suppression
5. Auto answer suppression
6. Carrier detect override
7. Power-on and ATZ reset software defaults
8. AT command set recognition

Separate wall socket power adapter for mains voltage appropriate to the market area, providing 20v AC at up to 750 mA, connected by twin cable to coaxial socket on the modem.

In late 1994 the web was beginning to take off, but most users could only connect to the internet via a dial-up modem, some at only 300 bit/s. The ITU-T V.34 recommendation for 28.8 kbit/s transmission had just been published in September 1994, and U.S. Robotics was one of the first companies to offer a compatible modem for personal computers. At that time few would have envisaged that a decade later VDSL2 modems using discrete multi-tone modulation would allow existing copper subscriber lines to carry data reliably at over 100 Mbit/s.

Here you find 2 models, 2 with images and 0 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
All listed radios etc. from U.S. Robotics, Inc. / USR; Chicago, Skokie, Schaumburg, IL