A modem coupler making it possible for a modem to access an analog signal telephone communication system directly from a multi-line key telephone set, the modem interfacing the system with a digital computer terminal or any other terminal that processes digital data. The modem coupler is self-sufficient...http://www.google.com/patents/US5014299?utm_source=gb-gplus-sharePatent US5014299 - Modem coupler for multi-line key telephone system
