found this http://www.ebay.com/itm/Sega-genesi...2082?pt=Video_Games_Games&hash=item3386758a02 mostly interested in the other box that seems to randomly load 6 other cartridges? maybe the one in the genesis is a boot loader?
That black box is a jukebox system called the Sega Demo System DS-16. I actually have one myself and I wrote half of the information in the link. The DS-16 basically allows you to switch between up to 6 games on the fly with a button. no powering down or resetting needed. The switcher button does it all. IT also has a timer built in to switch between games at set time limits. Takes standard game carts.
I remember seeing a magazine add for a sega "jukebox" game loader, It held six games and there was a boot game.