The Z1
Konrad had to repeatedly make calculations, he was tired of that. So Zuse started the design his invention the Z1 in his parents apartment in 1936. This is one of his first inventions that was first called the V1 but was later changed to Z1 because there was a rocket called the V1, and they didn't want any conection between them. He had studied the available mechanical calculating machines of that time, all of which were based on the decimal number system. He had never planned to build a modified or extended decimal machine, because he wanted to build a new type of computer for universal scientific applications. Most of the original pictures of the Z1 were destroyed by a bombing in World War II.