The reel-to-reel format was used in the earliest tape recorders, including the pioneering German-British Blattnerphone (1928) machines of the late 1920s which used steel tape, and the German Magnetophon machines of the 1930s. Originally, this format had no name, since all forms of magnetic tape recorders used it. The name arose only with the need to distinguish it from the several kinds of tape cartridges or cassettes such as the endless loop cartridge developed for radio station commercials and spot announcements in 1954, the full size cassette, developed by RCA in 1958 for home use, as well as the compact cassette developed by Philips in 1962, originally for dictation.