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:
Jan. 12, 1982
Filed:
Dec. 28, 1978
Paul W Hunter, San Jose, CA (US);
Alexander E Malaccorto, San Jose, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method and means are provided to increase the effective data transfer rate between a direct access storage device (DASD) and a central processing unit (CPU) communicating with the DAS device through a channel and a DASD control device. A command issued to the AS subsystem which requires mechanical motion in the DAS device is stored in the subsystem and the subsystem provides a response to the channel indicating that the command has been carried out, without actually carrying out the command. The channel responds by issuing one or more additional commands in the chain to the subsystem which may be carried out without mechanical motion. When a command is issued to the subsystem which again requires mechanical motion of the device, the control device causes the stored command to be executed essentially simultaneously with the newly received command. This execution of the stored command out of its normal sequence and in parallel with another command involving mechanical motion of the DAS device decreases the time required to perform operations with the DASD subsystem.