The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 29, 1980
Filed:
Jan. 23, 1978
Iain D Allan, Saratoga, CA (US);
Per-Erik Walberg, San Jose, CA (US);
Sperry Rand Corporation, New York, NY (US);
Abstract
A method and apparatus for accessing data blocks in a computer system having multiple-disk drive rotational position sensing which is not centrally synchronized and where data read and write requests are normally weighted by the order of availability of requested data blocks. The weighting of the priority, or queue position, of selected data blocks is modified by advancing the apparent initial location of data blocks designated for preferental access and maintaining an availability signal, or peripheral interrupt, for an extended period. A special pre-data-transfer instruction indicates the duration of the peripheral interrupt. A circuit for implementing the invention has a storage register for receiving the special instruction, a down counter for decrementing for the duration of the designated pre-data-interrupt and an interrupt duration control latch for issuing and extinguishing the interrupt. The invention permits preferential processing of demand type high priority data where there is no central clock synchronization among peripheral storage devices.