Modem adapter for use with standard PC parallel port
US5408614A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 17, 1993 |
| Grant date | Apr 18, 1995 |
| Priority date | — |
| Expiry date | Dec 17, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M11/06
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A modem adapter for use with a standard parallel port of a personal computer (PC) for interfacing to the public switched telephone network (PSTN). The modem adapter accepts digital data, eight bits at a time, from a standard PC parallel port and modulates this digital data into an analog format, compatible with the PSTN. Conversely, the modem adapter accepts analog data from the PSTN and converts it into digital data and transfers this data to the parallel port, at least four bits at a time. The modem adapter of the present invention thus neither requires any additional circuit cards in the PC's card slots nor dedication of any of the existing serial ports. Redirector software intercepts software I/O instructions directed toward a serial I/O port and redirects and reformats these instructions to the modem adapter through the parallel port. This redirection permits existing modem control software to be used without modification with the modem adapter of the present invention.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.