Z2 (computer)

The Z2 was an electromechanical (mechanical and relay-based) digital computer that was completed by Konrad Zuse in 1940.^[1][2][3] It was an improvement on the Z1 Zuse had 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.

Z2

Drawing of the Zuse Z2
Developer	Konrad Zuse
Type	Electromechanical (mechanical and relay-based) digital computer
Release date	1940; 85 years ago (1940)
CPU	600 electrical relay circuits @ ca. 5 Hz
Memory	64 words
Removable storage	Punch cards
Power	1000 watts
Weight	300 kg (660 lb)
Predecessor	Z1
Successor	Z3

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.^[4] 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^[1][2][3] (today DLR) and member Alfred Teichmann [de], whose support helped fund the successor model Z3.^[5]

Specifications

Frequency

c. 5 Hz

Arithmetic unit

Fixed point arithmetic unit with 16 bit word length

Average calculation time

0.8 sec for addition operation

Number of relays

600

Memory

64 words (same as Z1)

Power consumption

1000 watts

Weight

300 kg (660 lb)^[6]

See also

• Z4