Standard Elektrik Lorenz was a German manufacturer of electronic devices of many sorts, based in Stuttgart-Zuffenhausen. Its history reaches back to the early years of German electrical industry (with forerunners in 1880 and 1897). Since about 1930 and until 1987, the company was a subsidiary of ITT, before they were bought up by Alcatel and continued under the name Alcatel-SEL. Since then, the various parts of the widespread trust suffered a vivid history of more downs than ups, before they essentially disappeared.

In the context of digital art, only the manufacturing by SEL of the computer ER 56 is of importance. The Computing Center of the University of Stuttgart owned such a machine and used it for some years as their main computing device, when in the early 1960s the young Frieder Nake did his first works of computer art using this machine (since 1963).