"NOTE THAT THERE ARE TWO STYLES OF BOARDS.
The board in your system may be one of two styles. The early style has a RED LED. The EPROM is installed on this style with the notch towards the edge of the board. The later style has a YELLOW LED. The EPROM is installed on this style with the notch away from the edge of the board and in toward the center of the board.
Do Not Use the EPROM label as a reference. Failure to install the EPROM the correct way will destroy the EPROM and may damage the interface board.
Do not install a DataGuard 5 EPROM on a board with a RED LED