Method and apparatus for detecting cursors
CA 2010960 C · Owner: Sun Microsystems, Inc. · Inventors: Frank, Edward H.; Westberg, Thomas
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Apparatus and methods are disclosed which are most advantageously used with a digital computer for detecting the location of multiple cursors in a computer memory having parity bits. In one embodiment of the present invention the, normal parity checking scheme of the computer memory is modified, such that the parity bit is used to detect data locations containing cursor data. Writing new data to the frame buffer is implemented as a read-modified-write cycle. In another embodiment of the present invention the parity, checking of the computer memory is no longer used as such. Instead the memory controller has a mode that forces the parity bit to one of two states, independent of the contents …
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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
- Filed February 27, 1990 and granted December 21, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 27, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 27, 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.