Barr had earlier created an analysis-of-variance modeling language inspired by the notation of statistician Maurice Kendall. He developed it in assembly language on the IBM 1410, as a graduate student at North Carolina State University from 1962 to 1963. Dr. A. Grandage, author of IBM 650 analysis-of-variance programs, advised on some of the statistical computations. This was followed by a multiple regression program with a flexible input format and with algebraic transformation of variables, in 1963 to 1964. Drawing on those programs, along with his experience with structured data files, he created SAS, placing statistical procedures into a formatted file framework.