On one side of the module there are transistors, capacitors, diodes and resistors. "POS LEVEL TO DEC. LEVEL RECIEVER" is printed in solder on the top right edge on the circuit side. "January 31, 1974" is stamped on the component side.
Date
1966 ca.
Manufacturer
Digital Equipment Corporation (DEC)
Place Manufactured
Maynard, Mass.
Identifying Numbers
Model number
W591
Printed in black on the face of the beige extraction handle.
Other number
417
Stamped into the handle on the circuit side
Other number
W591A
Printed in solder on the left edge near the top on the circuit side