Yesterday my friend installed a new power supply into my 1983 Mario Bros. (conversion) and we noticed a weird 'adapter' that has been soldered onto the board. Actually, we found it a year ago, I'm FINALLY trying to find out what it is.
There were two Double AA batteries which were promptly removed for fear of leaking. Thinking it might be a high score saver we put in fresh batteries, but nothing. Apparently my machine has a counter in the coin box to keep track of how many games have been played, so another counter seems redundant.
Does anyone have any idea what this thing is?