This M502 "Negative Input Converter" module consists of numerous components on one side of the board. On the same side there is an inspection stamp. The circuit side of the board consists of printed conductors.
Manufacturer
Digital Equipment Corporation (DEC)
Place Manufactured
Maynard, Mass.
Identifying Numbers
Model number
M502
Printed on the extractor handle.
Other number
M502B
Printed with solder on the circuit side of the board.