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.

Date of Patent:
Oct. 13, 1987

Filed:

Nov. 18, 1985
Applicant:
Inventors:

Jay P Duncanson, San Francisco, CA (US);

Mark R Murray, Atlanta, GA (US);

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04L / ;
U.S. Cl.
CPC ...
375-8 ; 371 49 ; 375111 ; 379 93 ; 379 97 ;
Abstract

An improved modem is described which can selectably operate in a synchronous communications mode, an asynchronous data mode, and an asynchronous command mode. A processor 47 controls the operation of the modem, adds starting and ending flags and frame check sequences to transmitted data, searches for flags and sync characters in received data, adds and deletes start, stop and parity bits required for communications with the asynchronous communications element 18, and performs zero bit insertion and deletion for HDLC/SDLC communications. Processor 47 also controls and monitors the operating parameters of the modem engine 60.


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