Z2 (computer)

The Z2 was an electromechanical (mechanical and relay-based) computer that was completed by Konrad Zuse in 1940. It was an improvement on the Z1 Zuse built in his parents' home, which used the same mechanical memory. In the Z2, he replaced the arithmetic and control logic with 600 electrical relay circuits, weighing over 600 pounds. 
The Z2 could read 64 words from punch cards. Photographs and plans for the Z2 were destroyed by the Allied bombing during World War II. In contrast to the Z1, the Z2 used 16-bit fixed-point arithmetic instead of 22-bit floating point.
Zuse presented the Z2 in 1940 to members of the DVL (today DLR) and member Prof. Alfred Teichmann, whose support helped fund the successor model Z3.