There are three Standard Modular System (SMS) cards. Each has a three coiled transformer in the middle. There are also several resistors and diodes on the board.
Date
Circa 1959
Manufacturer
International Business Machines (IBM)
Identifying Numbers
Other number
598399
Stamped next to "IBM" on the component side on one of the modules
Other number
6200202
PECO number stamped in black on the component side of two of the cards
Other number
E.C. 246008
Engineering change number stamped on the component side of one of the cards
