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:
Nov. 03, 1998
Filed:
Dec. 11, 1997
Shanker Singh, Morgan Hill, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method and means in a stored, program-controlled machine to maintain an uninterrupted access and copying of simple parity-coded words of an initial program load (IPL) or other software from a read-only memory or a memory with limited rewrite capability in the presence of detectable errors, erasures, or faults. The method utilizes detected parity error in a word copied out from storage to modify the address register to seek the same word from a mirror address of an image copy of the IPL. The image copy is stored at a second range of consecutive memory address nonintersecting and symmetric with the address range of the original IPL. The IPL is then accessed in the second address range until either another parity error causes a switch back to the original IPL or the program terminates.