Dma emulation for non-dma capable interface cards
CA 2135505 C · Owner: Hon, Stephen · Inventors: Devins, Robert J.; Hon, Stephen; Keller, Emory D.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method and means are provided for simulating a direct memory access (DMA) function to access memory in a host computer having a DMA controller for the purpose of enabling the transfer of data between the host memory and a computer accessory data handling device not capable of DMA operation that can be operably connected to the host including determining the location in the host memory for data to be transferred from the host memory to the accessory data handling device or from the accessory data handling device to the host memory by reading the memory address contents of the DMA controller. Data is read from the host memory at the address specified in the DMA controller and written to the …
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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 November 9, 1994 and granted November 9, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 9, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 9, 2016.
- 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.