Colossus was a set of computers developed by British codebreakers in 1943–1945 to help in thecryptanalysis of the Lorenz cipher. Colossus used thermionic valves (vacuum tubes) to performBoolean and counting operations. Colossus is thus regarded^[2] as the world’s first programmable,electronic, digital computer, although it was programmed by switches and plugs and not by astored program
https://en.m.wikipedia.org/wiki/Colossus_computer