The board is covered in various active and passive components which are surrounded by an aluminum frame and a blue plastic 22 pin male connector. There are two round inspection stamps on the component side, one of which is very faint. On the solder side there is a grid lettered A-Z.
Date
1965 ca.
Manufacturer
Digital Equipment Corporation (DEC)
Identifying Numbers
Model number
4525C
Printed on the solder side of the board at the insertion end