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