Ruby slippers only runs on BB2. Other Wizard of Oz games for BB1 use a TSE box for the top display. A limited function device that isn't getting video from the CPU itself. Very different.
You can run those BB1 Wiz of Oz games on BB2's, but you need a TSE fooler box and only the lower screen actually works. But the games will play.
Dedicated BB2 Ruby slippers machines have a topper with screen/lighted marquee around the upper screen and on top. But the game plays just as well without having this, and why they have the option to disable it in the settings.
If the top overlay and marquee is removed, as far as video you see the same images on the screens.