Layered protection system for computer's hard disk
CA 2055606 A1 · Owner: Morrison, Gilbert W. · Inventors: Morrison, Gilbert W.; Myhre, Trygve C.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A system (10) and device (18) for controlling access to the hard disk memory portion of a computer on both hardware and software levels, with associated administrative control. A switching device (18) is inserted in the wiring between the hard disk controller and the hard disk (32), requiring the application of a key (34) or other suitable electronic or digital access means for operation of the switch allowing an unprotected mode a mode wherein a, disk (24) in a protected disk drive may be read from but not written to; a mode wherein a disk (24) in a protected disk drive may be written to but not read from and a mode wherein a disk (24) in a disk drive may neither be read from nor …
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 July 10, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 10, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 10, 2012.
- 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.