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:
May. 27, 1980
Filed:
Oct. 19, 1978
Henry Bardsley, III, Saratoga, CA (US);
Fernando A Luiz, Monte Sereno, CA (US);
Nils F Nilsen, Tucson, AZ (US);
Ronald C Simpson, San Jose, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method and means for the recovery of non-logged data by a CPU/channel from a storage subsystem, which data would normally be overwritten upon the subsystem being RESET by the CPU/channels. A defaulting control unit simultaneously initiates a DISCONNECT IN sequence to its attaching channels and sets an appropriate status bit at a control unit/control unit communications interface. The channel responds to the DISCONNECT IN with a SELECTIVE RESET interface sequence which sequence is buffered by the defaulting control unit. Meanwhile, the companion functioning control unit, when operating at its lowest interrupt level, polls the status bit periodically and offloads data registers through the interface connection from the defaulting unit within a predetermined time. At the end of this interval, the SELECTIVE RESET is honored, thereby erasing all data in the defaulting control unit registers.