The object consists of two symmetrically mounted groups of components with a capacitor and resistor between them and a common capacitor and resistor. Each half has five transistors two coils and other active and passive components. On the component side there are also three quality control stamps, one is barely visible. On the solder side there are lettered coordinates A-Z.
Date
1965 ca.
Manufacturer
Digital Equipment Corporation (DEC)
Place Manufactured
Maynard, Mass.
Identifying Numbers
Model number
4521C
Etched in solder at insertion end of board
Other number
41521
Engraved on the outside of the frame on the extraction end
Serial number
0196954
Engraved on the side of the frame toward the extraction end