 At that time, it was the only working computer in continental Europe, and the second computer in the world to be sold, beaten only by the BINAC, which never worked properly after it was delivered.Other computers, all numbered with a leading Z, up to Z43, were built by Zuse and his company.Notable are the Z11, which was sold to the optics industry and to universities, and the Z22, the first computer with a memory based on magnetic storage.