And then .. disaster! My MS boardset has developed a fault. Allow it to warm up a bit and corrupt flashy bars appear above and below the picture. The actual game screen is unchanged and all works, it's like the game is drawing extra memory above and below the actual boundary of the picture. I'm unfamiliar with Missile Command type hardware, does anyone have any suggestions? In fact in test mode where only white is used (it says ram/rom are ok), the corruption doesn't really change at all, then scrolls if you roll the trackball, almost like it's drawing the data area for the inputs under the screen.