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. 27, 1993
Filed:
Sep. 12, 1990
James W Sundet, Chippewa Falls, WI (US);
Roger G Brown, Colfax, WI (US);
Cray Research, Inc., Eagan, MN (US);
Abstract
A fault tolerant network for a plurality of computers includes a system for controlling access to shared peripherals. Access to the shared peripherals is coordinated among the computers by means of communication through a semaphore box. Each computer connects to the semaphore box via a channel. The semaphore box is comprised of two major sections: a semaphore section and an I/O section. The semaphore section contains two sets of semaphores: a first set comprising reservation semaphores for the shared peripherals; and a second set comprising heartbeat semaphores for the sharing computers. The first set is used to reserve a particular peripheral for a particular computer and indicate the source of the reservation; the second set provides a 'heartbeat' to prevent reservation semaphores from being set indefinitely in the event communication with a particular computer is lost.