 In 1940, the German government began funding him and his company through the "Aerodynamische Versuchsanstalt" (AVA, Aerodynamic Research Institute, forerunner of the DLR), which used his work for the production of glide bombs.Zuse built the S1 and S2 computing machines, which were special purpose devices which computed aerodynamic corrections to the wings of radio-controlled flying bombs.The S2 featured an integrated analog-to-digital converter under program control, making it the first process-controlled computer.