The Z5 was a computer built by Zuse from 1950 to 1952 and built by him from 1952 to 1953. The Z5 is the successor of the Z4, and is much more compact and powerful. Zuse implemented the machine with relays, since vacuum tubes were too unreliable at the time. The Z5 used the same princips as the Z4 did, but was six times faster. It also had punched tape readers, which the Z4 did not have. It was the fifth computer built by Konrad Zuse.