The Zuse palimpsest refers to the film stock used by Konrad Zuse to encode information for his Z3 computer, completed in 1941.
"During the war I couldn't get ordinary commercial punched-tape machines, which were than already in use in the telephone business for 5-track punched tape. I built my own punching and reading devices and used normal filmstrips--[Helmut] Schreyer's idea. They were punched with a simple manual keypunch" --Konrad Zuse, The Computer--My Life (Berlin: Springer-Verlag, 1984), 63.
The film strips encoded binary data in successive rows of 8 dots per row. The image on the film was unimportant, a mere trace of the medium's former life.