<一般論文>コンラート・ツーゼにおける計算機観--計算機械から汎用情報処理機械へ--

Abstract

Konrad Zuse, a German computer pioneer, is widely known for having made the binary, fully-functional, and programmable computer (Z3), which became opera-tional in 1941. Besides this achievement, he is also known for his work on the first high-level programming language, "Plankalkül, " designed in the middle of 1940s when the Second World War and postwar era confusion disturbed (or stopped) his hardware construction efforts. There is, however, a kind of gap between these two areas of his work. On the one hand all his computing machines made before 1945 have a lack of conditional branching, and on the other, one can write complicated programs including con-ditional branching and looping with Plankalkül. Because of this gap, it is almost impossible for his computer to execute programs written in Plankalkül.Through consideration of his writings in the period of 1935–45, I have attempted to show how Zuse changed his views on the meaning ofRechnen (engl. reckoning, computing) during the development of his binary calculation theory, and that his hardware-construction and theoretical programming language design activities had influence on each other. For instance, his hardware-construction works called for a binary calculation method which led to Plankalkül, and conversely, his theoretical works urged him to enable the Z4 to execute conditional branching and stimulated him into making "Planfertigungsgerät".