Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US05/945,921external-prioritypatent/US4266880A/en
Priority claimed from US05/945,922external-prioritypatent/US4273456A/en
Priority claimed from US05/945,953external-prioritypatent/US4272205A/en
Application filed by International Business Machines CorporationfiledCriticalInternational Business Machines Corporation
Priority claimed from EP79102457Aexternal-prioritypatent/EP0009086B1/de
Application grantedgrantedCritical
Publication of ATE507T1publicationCriticalpatent/ATE507T1/de