Hardware protection control for computer storage devices
CA 2091501 C · Owner: Elliott, Thomas E. · Inventors: Gonzalez, Richard L.; Elliott, Thomas E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A write protect device for a computer comprising a hardware circuit with a switch connected to an internally installed circuit card which has cable connections between data storage device drives and a drive controller cable the circuit, card intercepting control lines used for drive selection and control. The switch is connected to inputs of a latch circuit which, in one position of the switch, generates *READONLY and READONLY signals at outputs of the latch circuit and *DISABLE and DISABLE signals at other outputs when the switch is placed in a second position. The circuit card includes an inverter and a NAND gate in a *WRITE GATE line to the data storage device drives with one input of …
Read the whole patent
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
- Filed March 11, 1993 and granted April 24, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 11, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 11, 2015.
- 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.