I won this machine last night from the Goodwill auction site. Any idea what this switch is for? Unfortunately, I only have this photo from the listing until I go pick the machine up - probably later today.
Also there is a pic of the serial #. With what I think is a copyright date of 1989, I am hoping this a ROM 3 machine but I wanted to check the serial # to be sure. I have a feeling someone here knows how to decipher it.