O Leon Pierce, Mark C Smith, R Byron Driver: Line powered modem. Universal Data Systems, Weingarten Schurgin Gagnebin & Hayes, July 26, 1983: US04395590 (60 worldwide citation)

A modem for coupling a data terminal or other apparatus to a telephone line and deriving its operating power for both transmitting and receiving operation from the telephone line, and providing electrical isolation between the telephone line and the data terminal.

R Byron Driver: Line powered modem automatic answer device powered from equipment. Universal Data Systems, Weingarten Schurgin Gagnebin & Hayes, November 15, 1983: US04415774 (53 worldwide citation)

An automatic answering device controlled by attached data equipment and used with a modem powered from the telephone line. The modem and automatic answering device are automatically connected to and subsequently powered by the telephone line when a ring signal has occurred on the telephone line and ...

R Byron Driver, Larry Fullerton: Balanced biphase transmitter using reduced amplitude of longer pulses. Complexx Systems, Schwartz Jeffery Schwaab Mack Blumenthal & Evans, June 17, 1986: US04596023 (10 worldwide citation)

The data communication system includes an encoder to receive nonreturn-to-zero data signals and convert them to biphase signals, a current mode transmitter for transmitting the biphase signals, and a communication link connected to the transmitter. The encoder senses transitions in the nonreturn-to- ...