Don't take our word as gospel. i mean, until you power it up and look at it on the monitor, you can't know for sure 100% what the board is. I don't know much about some of the older boards, but i know there where conversion kits available for some games to convert them to another game with just a swap of the roms, since the rest of the hardware was the same. perhaps this used to be a mappy and was converted to dig dug

That said, if that's what it is, and you like dig dug, keep it and play it...if not, sell it off and buy yourself a few buttons.