For an honest answer, I would guess this is some sort of link card for a game with an internet ranking system. The Serial port (it is NOT a VGA, VGA housings are blue and COM Serial housings are black) would be used for the local linking, and the MODEM ports would be used for the internet connectivity. Best guess would be for a racing game that allowed local linking and a universal member ID number for you to record your rankings. I know a few of the old racers allowed for a function like that and a keypad to enter your pin number. There is also a 16pin header on there, which would connect to the mobo. The screw terminals would probably supply DC power to the card.