U.S. Robotics Corporation, often called USR, is a company that produces USRobotics computer modems and related products. Its initial marketing was aimed at bulletin board systems, where its high-speed HST protocol made FidoNet transfers much faster, and thus less costly. During the 1990s it became a major consumer brand with its Sportster line. The company had a reputation for high quality and support for the latest communications standards as they emerged, notably in its V.Everything line, released in 1996.
USRobotics Courier 2400 Modem with serial cable attached (mid-late 1980s)
U.S. Robotics Sportster 14,400 Fax Modem (1994)
USR Sportster 56k 117102 ISA modem supporting X2 and V.90
Courier Dual Standard V34 Fax with V32 bis
A modulator-demodulator or modem is a computer hardware device that converts data from a digital format into a format suitable for an analog transmission medium such as telephone or radio. A modem transmits data by modulating one or more carrier wave signals to encode digital information, while the receiver demodulates the signal to recreate the original digital information. The goal is to produce a signal that can be transmitted easily and decoded reliably. Modems can be used with almost any means of transmitting analog signals, from light-emitting diodes to radio.
Acoustic coupler modems used a telephone handset as the audio medium, with the user dialing the desired number and then pressing the handset into the modem to complete the connection. These systems generally operated at a speed of 300 bits per second.
Collection of modems once used in Australia, including dial-up, DSL, and cable modems
TeleGuide terminal
The original 300-baud Hayes Smartmodem