 Mailüfterl was built from May 1956 to May 1958 at the Vienna University of Technology by Heinz Zemanek.Heinz Zemanek had come to an agreement with Konrad Zuse, whose company Zuse KG would finance the work of Rudolf Bodo, who helped build the Mailüfterl, also that all circuit diagrams of the Z22 were supplied to Bodo and Zemanek, and that after the Mailüfterl project Bodo should work for the Zuse KG to help build the transistorized Z23.The first program, computation of the prime 5,073,548,261, was executed in May 1958.