The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 18, 1995
Filed:
Dec. 17, 1993
Timothy J Thornton, Camarillo, CA (US);
Robert Rosen, Agoura Hills, CA (US);
Eric K Henderson, Agoura, CA (US);
Xircom, Inc., Calabasas, CA (US);
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.