This Z23 circuit board has heat marks where some components are attached. There are two inspection marks on the component side. The handwritten description on the sticker reads "getestet 17 20A stromuers. (2N512) OV. 9.9.71".
Date
1961 ca.
Manufacturer
Zuse
Identifying Numbers
Other number
OC 26-2 WB
Component side on large metal component closest to insertion end