System for programmed operation of direct access storage device (dasd) subsystems
CA 2027992 C · Owner: International Business Machines Corporation · Inventors: Ottesen, Hjalmar Holmboe; Greenberg, Richard; Glaser, Thomas William
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A data processing system is disclosed having a direct access storage device (DASD) subsystem comprising a number of separate physical housings, each housing having a number of disk supporting spindles mounted therein. The velocity of rotation of the spindles within a housing is synchronized, and the rotational position of the spindles may be locked into a fixed relationship. When number N of disk supporting spindles are provided spindle rotation is synchronized, and mirrored data files are written out of phase by 360/N degrees thereby, providing reduced latency time during a subsequent read operation, while at the same time providing data integrity through the use of redundant data files.
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 October 18, 1990 and granted November 29, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 18, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 18, 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.