Granted Patent
Utility
US 4,439,864 · App. 06/136,503
Modem circuitry
Inventor:
Shahid U. H. Qureshi
Patented Case
View Patent ↗
Granted: Mar 27, 1984
Filed: Apr 3, 1980
Inventor
Shahid U. H. Qureshi
Assignee (at issue)
Codex Corporation
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.