Of computers. Machines whose designs were started after 1955 (approximately) and are characterized by both vacuum tube (valve) and discrete transistor logic. They used magnetic core main memory. By this time a wider range of input/output equipment was beginning to be available, with higher-performance magnetic tape and the first forms of online storage (magnetic drums and early magnetic disks). Models of such online storage devices include magnetic drums in the UNIVAC LARC and 1105, and early disks in the IBM 1401–1410. During the second generation, initial efforts at automatic programming produced B0, Commercial Translator, FACT, Fortran, and Mathmatic as programming languages, these in turn influencing the development of the third generation languages – Cobol and later versions of Fortran. See also Atlas.