Four wire keyboard interface
CA 1264095 C · Owner: Eberhard, Martin F. · Inventors: Eberhard, Martin F.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A computer system comprises a terminal and a keyboard, the terminal comprises a central control means for controlling the operator of the keyboard and the keyboard comprises a switch array, the switch array has a plurality of rows and a plurality of columns. The terminal further comprises a data output port for transmitting a command signal from the terminal central control means and a data input port for receiving a data signal from the keyboard. The command signal comprises a keyboard initialize signal and a keyboard increment signal. The keyboard further comprises a four-wire keyboard interface means for communicating with the terminal. The four-wire keyboard interface means facilitates …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted December 27, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended December 27, 2006.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.