Widely considered the first software patent, "Prater-Wei" was about calculating temperatures for petroleum fractionation. This patent, originally filed by Mobil Oil Corporation in 1960, addressed computerized spectographic analysis. It had many method and apparatus claims that could be performed either on an analog or digital computer, or with pencil and paper. At the time, software was not patentable, so the authors described a non-computer method of choosing the temperatures, using matrix inversion. However, the description in the patent application used linear algebra notation similar to that of textbooks published late in the 19th century to disguise the more obvious matrix notation that was invented much later. (adapted from Henry Gladney, Digital Document Quarterly 4.2, and Digital Document Quarterly 7.3, accessed 01-01-2009).
"A Court of Customs and Patent Appeals (CCPA) decision is famous because the question "whether computer programs could contain patentable subject matter" was also before the CCPA. See Application of Charles D. Prater and James Wei, U.S. CCPA, 415 F.2d 1378, November 20, 1968." (Henry Gladney, Digital Document Quarterly 7,3, accessed 01-01-2009).